Programs & Examples On #Nested

This tag relates to any of various nested entities or operations in programming.

python "TypeError: 'numpy.float64' object cannot be interpreted as an integer"

Similar situation. It was working. Then, I started to include pytables. At first view, no reason to errors. I decided to use another function, that has a domain constraint (elipse) and received the following error:

TypeError: 'numpy.float64' object cannot be interpreted as an integer

or

TypeError: 'numpy.float64' object is not iterable

The crazy thing: the previous function I was using, no code changed, started to return the same error. My intermediary function, already used was:

def MinMax(x, mini=0, maxi=1)
    return max(min(x,mini), maxi)

The solution was avoid numpy or math:

def MinMax(x, mini=0, maxi=1)
    x = [x_aux if x_aux > mini else mini for x_aux in x]
    x = [x_aux if x_aux < maxi else maxi for x_aux in x]
    return max(min(x,mini), maxi)

Then, everything calm again. It was like one library possessed max and min!

Margin on child element moves parent element

This is what worked for me

.parent {
padding-top: 1px;
margin-top: -1px;
}

.child {
margin-top:260px;
}

http://jsfiddle.net/97fzwuxh/

Nested ifelse statement

With data.table, the solutions is:

DT[, idnat2 := ifelse(idbp %in% "foreign", "foreign", 
        ifelse(idbp %in% c("colony", "overseas"), "overseas", "mainland" ))]

The ifelse is vectorized. The if-else is not. Here, DT is:

    idnat     idbp
1  french mainland
2  french   colony
3  french overseas
4 foreign  foreign

This gives:

   idnat     idbp   idnat2
1:  french mainland mainland
2:  french   colony overseas
3:  french overseas overseas
4: foreign  foreign  foreign

How to use a dot "." to access members of dictionary?

You can do it using this class I just made. With this class you can use the Map object like another dictionary(including json serialization) or with the dot notation. I hope to help you:

class Map(dict):
    """
    Example:
    m = Map({'first_name': 'Eduardo'}, last_name='Pool', age=24, sports=['Soccer'])
    """
    def __init__(self, *args, **kwargs):
        super(Map, self).__init__(*args, **kwargs)
        for arg in args:
            if isinstance(arg, dict):
                for k, v in arg.iteritems():
                    self[k] = v

        if kwargs:
            for k, v in kwargs.iteritems():
                self[k] = v

    def __getattr__(self, attr):
        return self.get(attr)

    def __setattr__(self, key, value):
        self.__setitem__(key, value)

    def __setitem__(self, key, value):
        super(Map, self).__setitem__(key, value)
        self.__dict__.update({key: value})

    def __delattr__(self, item):
        self.__delitem__(item)

    def __delitem__(self, key):
        super(Map, self).__delitem__(key)
        del self.__dict__[key]

Usage examples:

m = Map({'first_name': 'Eduardo'}, last_name='Pool', age=24, sports=['Soccer'])
# Add new key
m.new_key = 'Hello world!'
# Or
m['new_key'] = 'Hello world!'
print m.new_key
print m['new_key']
# Update values
m.new_key = 'Yay!'
# Or
m['new_key'] = 'Yay!'
# Delete key
del m.new_key
# Or
del m['new_key']

Test for existence of nested JavaScript object key

I have created a little function to get nested object properties safely.

function getValue(object, path, fallback, fallbackOnFalsy) {
    if (!object || !path) {
        return fallback;
    }

    // Reduces object properties to the deepest property in the path argument.
    return path.split('.').reduce((object, property) => {
       if (object && typeof object !== 'string' && object.hasOwnProperty(property)) {
            // The property is found but it may be falsy.
            // If fallback is active for falsy values, the fallback is returned, otherwise the property value.
            return !object[property] && fallbackOnFalsy ? fallback : object[property];
        } else {
            // Returns the fallback if current chain link does not exist or it does not contain the property.
            return fallback;
        }
    }, object);
}

Or a simpler but slightly unreadable version:

function getValue(o, path, fb, fbFalsy) {
   if(!o || !path) return fb;
   return path.split('.').reduce((o, p) => o && typeof o !== 'string' && o.hasOwnProperty(p) ? !o[p] && fbFalsy ? fb : o[p] : fb, o);
}

Or even shorter but without fallback on falsy flag:

function getValue(o, path, fb) {
   if(!o || !path) return fb;
   return path.split('.').reduce((o, p) => o && typeof o !== 'string' && o.hasOwnProperty(p) ? o[p] : fb, o);
}

I have test with:

const obj = {
    c: {
        a: 2,
        b: {
            c: [1, 2, 3, {a: 15, b: 10}, 15]
        },
        c: undefined,
        d: null
    },
    d: ''
}

And here are some tests:

// null
console.log(getValue(obj, 'c.d', 'fallback'));

// array
console.log(getValue(obj, 'c.b.c', 'fallback'));

// array index 2
console.log(getValue(obj, 'c.b.c.2', 'fallback'));

// no index => fallback
console.log(getValue(obj, 'c.b.c.10', 'fallback'));

To see all the code with documentation and the tests I've tried you can check my github gist: https://gist.github.com/vsambor/3df9ad75ff3de489bbcb7b8c60beebf4#file-javascriptgetnestedvalues-js

Nested jQuery.each() - continue/break

There is no clean way to do this and like @Nick mentioned above it might just be easier to use the old school way of loops as then you can control this. But if you want to stick with what you got there is one way you could handle this. I'm sure I will get some heat for this one. But...

One way you could do what you want without an if statement is to raise an error and wrap your loop with a try/catch block:

try{
$(sentences).each(function() {
    var s = this;
    alert(s);
    $(words).each(function(i) {
        if (s.indexOf(this) > -1)
        {
            alert('found ' + this);
            throw "Exit Error";
        }
    });
});
}
catch (e)
{
    alert(e)
}

Ok, let the thrashing begin.

Can regular expressions be used to match nested patterns?

Using regular expressions to check for nested patterns is very easy.

'/(\((?>[^()]+|(?1))*\))/'

Extract first item of each sublist

You could use zip:

>>> lst=[[1,2,3],[11,12,13],[21,22,23]]
>>> zip(*lst)[0]
(1, 11, 21)

Or, Python 3 where zip does not produce a list:

>>> list(zip(*lst))[0]
(1, 11, 21)

Or,

>>> next(zip(*lst))
(1, 11, 21)

Or, (my favorite) use numpy:

>>> import numpy as np
>>> a=np.array([[1,2,3],[11,12,13],[21,22,23]])
>>> a
array([[ 1,  2,  3],
       [11, 12, 13],
       [21, 22, 23]])
>>> a[:,0]
array([ 1, 11, 21])

Best way to do nested case statement logic in SQL Server

This example might help you, the picture shows how SQL case statement will look like when there are if and more than one inner if loops

enter image description here

How can I access and process nested objects, arrays or JSON?

Accessing dynamically multi levels object.

var obj = {
  name: "john doe",
  subobj: {
    subsubobj: {
      names: "I am sub sub obj"
    }
  }
};

var level = "subobj.subsubobj.names";
level = level.split(".");

var currentObjState = obj;

for (var i = 0; i < level.length; i++) {
  currentObjState = currentObjState[level[i]];
}

console.log(currentObjState);

Working fiddle: https://jsfiddle.net/andreitodorut/3mws3kjL/

Objects inside objects in javascript

You may have as many levels of Object hierarchy as you want, as long you declare an Object as being a property of another parent Object. Pay attention to the commas on each level, that's the tricky part. Don't use commas after the last element on each level:

{el1, el2, {el31, el32, el33}, {el41, el42}}

_x000D_
_x000D_
var MainObj = {_x000D_
_x000D_
  prop1: "prop1MainObj",_x000D_
  _x000D_
  Obj1: {_x000D_
    prop1: "prop1Obj1",_x000D_
    prop2: "prop2Obj1",    _x000D_
    Obj2: {_x000D_
      prop1: "hey you",_x000D_
      prop2: "prop2Obj2"_x000D_
    }_x000D_
  },_x000D_
    _x000D_
  Obj3: {_x000D_
    prop1: "prop1Obj3",_x000D_
    prop2: "prop2Obj3"_x000D_
  },_x000D_
  _x000D_
  Obj4: {_x000D_
    prop1: true,_x000D_
    prop2: 3_x000D_
  }  _x000D_
};_x000D_
_x000D_
console.log(MainObj.Obj1.Obj2.prop1);
_x000D_
_x000D_
_x000D_

Can you write nested functions in JavaScript?

Not only can you return a function which you have passed into another function as a variable, you can also use it for calculation inside but defining it outside. See this example:

    function calculate(a,b,fn) {
      var c = a * 3 + b + fn(a,b);
      return  c;
    }

    function sum(a,b) {
      return a+b;
    }

    function product(a,b) {
      return a*b;
    }

    document.write(calculate (10,20,sum)); //80
    document.write(calculate (10,20,product)); //250

PHP foreach with Nested Array?

If you know the number of levels in nested arrays you can simply do nested loops. Like so:

//  Scan through outer loop
foreach ($tmpArray as $innerArray) {
    //  Check type
    if (is_array($innerArray)){
        //  Scan through inner loop
        foreach ($innerArray as $value) {
            echo $value;
        }
    }else{
        // one, two, three
        echo $innerArray;
    }
}

if you do not know the depth of array you need to use recursion. See example below:

//  Multi-dementional Source Array
$tmpArray = array(
    array("one", array(1, 2, 3)),
    array("two", array(4, 5, 6)),
    array("three", array(
            7,
            8,
            array("four", 9, 10)
    ))
);

//  Output array
displayArrayRecursively($tmpArray);

/**
 * Recursive function to display members of array with indentation
 *
 * @param array $arr Array to process
 * @param string $indent indentation string
 */
function displayArrayRecursively($arr, $indent='') {
    if ($arr) {
        foreach ($arr as $value) {
            if (is_array($value)) {
                //
                displayArrayRecursively($value, $indent . '--');
            } else {
                //  Output
                echo "$indent $value \n";
            }
        }
    }
}

The code below with display only nested array with values for your specific case (3rd level only)

$tmpArray = array(
    array("one", array(1, 2, 3)),
    array("two", array(4, 5, 6)),
    array("three", array(7, 8, 9))
);

//  Scan through outer loop
foreach ($tmpArray as $inner) {

    //  Check type
    if (is_array($inner)) {
        //  Scan through inner loop
        foreach ($inner[1] as $value) {
           echo "$value \n";
        }
    }
}

Nested classes' scope?

Easiest solution:

class OuterClass:
    outer_var = 1
    class InnerClass:
        def __init__(self):
            self.inner_var = OuterClass.outer_var

It requires you to be explicit, but doesn't take much effort.

How to query nested objects?

Since there is a lot of confusion about queries MongoDB collection with sub-documents, I thought its worth to explain the above answers with examples:

First I have inserted only two objects in the collection namely: message as:

> db.messages.find().pretty()
{
    "_id" : ObjectId("5cce8e417d2e7b3fe9c93c32"),
    "headers" : {
        "From" : "[email protected]"
    }
}
{
    "_id" : ObjectId("5cce8eb97d2e7b3fe9c93c33"),
    "headers" : {
        "From" : "[email protected]",
        "To" : "[email protected]"
    }
}
>

So what is the result of query: db.messages.find({headers: {From: "[email protected]"} }).count()

It should be one because these queries for documents where headers equal to the object {From: "[email protected]"}, only i.e. contains no other fields or we should specify the entire sub-document as the value of a field.

So as per the answer from @Edmondo1984

Equality matches within sub-documents select documents if the subdocument matches exactly the specified sub-document, including the field order.

From the above statements, what is the below query result should be?

> db.messages.find({headers: {To: "[email protected]", From: "[email protected]"}  }).count()
0

And what if we will change the order of From and To i.e same as sub-documents of second documents?

> db.messages.find({headers: {From: "[email protected]", To: "[email protected]"}  }).count()
1

so, it matches exactly the specified sub-document, including the field order.

For using dot operator, I think it is very clear for every one. Let's see the result of below query:

> db.messages.find( { 'headers.From': "[email protected]" }  ).count()
2

I hope these explanations with the above example will make someone more clarity on find query with sub-documents.

How can I combine multiple nested Substitute functions in Excel?

  • nesting SUBSTITUTE() in a string can be nasty, however, it's always possible to arrange it:

Screenshot formula bar

List comprehension on a nested list?

If you don't like nested list comprehensions, you can make use of the map function as well,

>>> from pprint import pprint

>>> l = l = [['40', '20', '10', '30'], ['20', '20', '20', '20', '20', '30', '20'], ['30', '20', '30', '50', '10', '30', '20', '20', '20'], ['100', '100'], ['100', '100', '100', '100', '100'], ['100', '100', '100', '100']] 

>>> pprint(l)
[['40', '20', '10', '30'],
['20', '20', '20', '20', '20', '30', '20'],
['30', '20', '30', '50', '10', '30', '20', '20', '20'],
['100', '100'],
['100', '100', '100', '100', '100'],
['100', '100', '100', '100']]

>>> float_l = [map(float, nested_list) for nested_list in l]

>>> pprint(float_l)
[[40.0, 20.0, 10.0, 30.0],
[20.0, 20.0, 20.0, 20.0, 20.0, 30.0, 20.0],
[30.0, 20.0, 30.0, 50.0, 10.0, 30.0, 20.0, 20.0, 20.0],
[100.0, 100.0],
[100.0, 100.0, 100.0, 100.0, 100.0],
[100.0, 100.0, 100.0, 100.0]]

How do you overcome the HTML form nesting limitation?

Well, if you submit a form, browser also sends a input submit name and value. So what yo can do is

<form   
 action="/post/dispatch/too_bad_the_action_url_is_in_the_form_tag_even_though_conceptually_every_submit_button_inside_it_may_need_to_post_to_a_diffent_distinct_url"  
method="post">  

    <input type="text" name="foo" /> <!-- several of those here -->  
    <div id="toolbar">
        <input type="submit" name="action:save" value="Save" />
        <input type="submit" name="action:delete" value="Delete" />
        <input type="submit" name="action:cancel" value="Cancel" />
    </div>
</form>

so on server side you just look for parameter that starts width string "action:" and the rest part tells you what action to take

so when you click on button Save browser sends you something like foo=asd&action:save=Save

Single Line Nested For Loops

You might be interested in itertools.product, which returns an iterable yielding tuples of values from all the iterables you pass it. That is, itertools.product(A, B) yields all values of the form (a, b), where the a values come from A and the b values come from B. For example:

import itertools

A = [50, 60, 70]
B = [0.1, 0.2, 0.3, 0.4]

print [a + b for a, b in itertools.product(A, B)]

This prints:

[50.1, 50.2, 50.3, 50.4, 60.1, 60.2, 60.3, 60.4, 70.1, 70.2, 70.3, 70.4]

Notice how the final argument passed to itertools.product is the "inner" one. Generally, itertools.product(a0, a1, ... an) is equal to [(i0, i1, ... in) for in in an for in-1 in an-1 ... for i0 in a0]

How do you create nested dict in Python?

This thing is empty nested list from which ne will append data to empty dict

ls = [['a','a1','a2','a3'],['b','b1','b2','b3'],['c','c1','c2','c3'], 
['d','d1','d2','d3']]

this means to create four empty dict inside data_dict

data_dict = {f'dict{i}':{} for i in range(4)}
for i in range(4):
    upd_dict = {'val' : ls[i][0], 'val1' : ls[i][1],'val2' : ls[i][2],'val3' : ls[i][3]}

    data_dict[f'dict{i}'].update(upd_dict)

print(data_dict)

The output

{'dict0': {'val': 'a', 'val1': 'a1', 'val2': 'a2', 'val3': 'a3'}, 'dict1': {'val': 'b', 'val1': 'b1', 'val2': 'b2', 'val3': 'b3'},'dict2': {'val': 'c', 'val1': 'c1', 'val2': 'c2', 'val3': 'c3'}, 'dict3': {'val': 'd', 'val1': 'd1', 'val2': 'd2', 'val3': 'd3'}}

MySQL Nested Select Query?

You just need to write the first query as a subquery (derived table), inside parentheses, pick an alias for it (t below) and alias the columns as well.

The DISTINCT can also be safely removed as the internal GROUP BY makes it redundant:

SELECT DATE(`date`) AS `date` , COUNT(`player_name`) AS `player_count`
FROM (
    SELECT MIN(`date`) AS `date`, `player_name`
    FROM `player_playtime`
    GROUP BY `player_name`
) AS t
GROUP BY DATE( `date`) DESC LIMIT 60 ;

Since the COUNT is now obvious that is only counting rows of the derived table, you can replace it with COUNT(*) and further simplify the query:

SELECT t.date , COUNT(*) AS player_count
FROM (
    SELECT DATE(MIN(`date`)) AS date
    FROM player_playtime
    GROUP BY player_name
) AS t
GROUP BY t.date DESC LIMIT 60 ;

Nested select statement in SQL Server

The answer provided by Joe Stefanelli is already correct.

SELECT name FROM (SELECT name FROM agentinformation) as a  

We need to make an alias of the subquery because a query needs a table object which we will get from making an alias for the subquery. Conceptually, the subquery results are substituted into the outer query. As we need a table object in the outer query, we need to make an alias of the inner query.

Statements that include a subquery usually take one of these forms:

  • WHERE expression [NOT] IN (subquery)
  • WHERE expression comparison_operator [ANY | ALL] (subquery)
  • WHERE [NOT] EXISTS (subquery)

Check for more subquery rules and subquery types.

More examples of Nested Subqueries.

  1. IN / NOT IN – This operator takes the output of the inner query after the inner query gets executed which can be zero or more values and sends it to the outer query. The outer query then fetches all the matching [IN operator] or non matching [NOT IN operator] rows.

  2. ANY – [>ANY or ANY operator takes the list of values produced by the inner query and fetches all the values which are greater than the minimum value of the list. The

e.g. >ANY(100,200,300), the ANY operator will fetch all the values greater than 100.

  1. ALL – [>ALL or ALL operator takes the list of values produced by the inner query and fetches all the values which are greater than the maximum of the list. The

e.g. >ALL(100,200,300), the ALL operator will fetch all the values greater than 300.

  1. EXISTS – The EXISTS keyword produces a Boolean value [TRUE/FALSE]. This EXISTS checks the existence of the rows returned by the sub query.

Nested routes with react router v4 / v5

A complete answer for React Router v5.


const Router = () => {
  return (
    <Switch>
      <Route path={"/"} component={LandingPage} exact />
      <Route path={"/games"} component={Games} />
      <Route path={"/game-details/:id"} component={GameDetails} />
      <Route
        path={"/dashboard"}
        render={({ match: { path } }) => (
          <Dashboard>
            <Switch>
              <Route
                exact
                path={path + "/"}
                component={DashboardDefaultContent}
              />
              <Route path={`${path}/inbox`} component={Inbox} />
              <Route
                path={`${path}/settings-and-privacy`}
                component={SettingsAndPrivacy}
              />
              <Redirect exact from={path + "/*"} to={path} />
            </Switch>
          </Dashboard>
        )}
      />
      <Route path="/not-found" component={NotFound} />
      <Redirect exact from={"*"} to={"/not-found"} />
    </Switch>
  );
};

export default Router;
const Dashboard = ({ children }) => {
  return (
    <Grid
      container
      direction="row"
      justify="flex-start"
      alignItems="flex-start"
    >
      <DashboardSidebarNavigation />
      {children}
    </Grid>
  );
};

export default Dashboard;

Github repo is here. https://github.com/webmasterdevlin/react-router-5-demo

Why would one use nested classes in C++?

I don't use nested classes much, but I do use them now and then. Especially when I define some kind of data type, and I then want to define a STL functor designed for that data type.

For example, consider a generic Field class that has an ID number, a type code and a field name. If I want to search a vector of these Fields by either ID number or name, I might construct a functor to do so:

class Field
{
public:
  unsigned id_;
  string name_;
  unsigned type_;

  class match : public std::unary_function<bool, Field>
  {
  public:
    match(const string& name) : name_(name), has_name_(true) {};
    match(unsigned id) : id_(id), has_id_(true) {};
    bool operator()(const Field& rhs) const
    {
      bool ret = true;
      if( ret && has_id_ ) ret = id_ == rhs.id_;
      if( ret && has_name_ ) ret = name_ == rhs.name_;
      return ret;
    };
    private:
      unsigned id_;
      bool has_id_;
      string name_;
      bool has_name_;
  };
};

Then code that needs to search for these Fields can use the match scoped within the Field class itself:

vector<Field>::const_iterator it = find_if(fields.begin(), fields.end(), Field::match("FieldName"));

Return value from nested function in Javascript

Just FYI, Geocoder is asynchronous so the accepted answer while logical doesn't really work in this instance. I would prefer to have an outside object that acts as your updater.

var updater = {};

function geoCodeCity(goocoord) { 
    var geocoder = new google.maps.Geocoder();
    geocoder.geocode({
        'latLng': goocoord
    }, function(results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
            updater.currentLocation = results[1].formatted_address;
        } else {
            if (status == "ERROR") { 
                    console.log(status);
                }
        }
    });
};

Nesting queries in SQL

You need to join the two tables and then filter the result in where clause:

SELECT country.name as country, country.headofstate 
from country
inner join city on city.id = country.capital
where city.population > 100000
and country.headofstate like 'A%'

Accessing nested JavaScript objects and arrays by string path

using eval:

var part1name = eval("someObject.part1.name");

wrap to return undefined on error

function path(obj, path) {
    try {
        return eval("obj." + path);
    } catch(e) {
        return undefined;
    }
}

http://jsfiddle.net/shanimal/b3xTw/

Please use common sense and caution when wielding the power of eval. It's a bit like a light saber, if you turn it on there's a 90% chance you'll sever a limb. Its not for everybody.

CASE statement in SQLite query

The syntax is wrong in this clause (and similar ones)

    CASE lkey WHEN lkey > 5 THEN
        lkey + 2
    ELSE
        lkey
    END

It's either

    CASE WHEN [condition] THEN [expression] ELSE [expression] END

or

    CASE [expression] WHEN [value] THEN [expression] ELSE [expression] END

So in your case it would read:

    CASE WHEN lkey > 5 THEN
        lkey + 2
    ELSE
        lkey
    END

Check out the documentation (The CASE expression):

http://www.sqlite.org/lang_expr.html

Retrieving values from nested JSON Object

Maybe you're not using the latest version of a JSON for Java Library.

json-simple has not been updated for a long time, while JSON-Java was updated 2 month ago.

JSON-Java can be found on GitHub, here is the link to its repo: https://github.com/douglascrockford/JSON-java

After switching the library, you can refer to my sample code down below:

public static void main(String[] args) {
    String JSON = "{\"LanguageLevels\":{\"1\":\"Pocz\\u0105tkuj\\u0105cy\",\"2\":\"\\u015arednioZaawansowany\",\"3\":\"Zaawansowany\",\"4\":\"Ekspert\"}}\n";

    JSONObject jsonObject = new JSONObject(JSON);
    JSONObject getSth = jsonObject.getJSONObject("LanguageLevels");
    Object level = getSth.get("2");

    System.out.println(level);
}

And as JSON-Java open-sourced, you can read the code and its document, they will guide you through.

Hope that it helps.

VBA EXCEL Multiple Nested FOR Loops that Set two variable for expression

I can't get to your google docs file at the moment but there are some issues with your code that I will try to address while answering

Sub stituterangersNEW()
Dim t As Range
Dim x As Range
Dim dify As Boolean
Dim difx As Boolean
Dim time2 As Date
Dim time1 As Date

    'You said time1 doesn't change, so I left it in a singe cell.
    'If that is not correct, you will have to play with this some more.
    time1 = Range("A6").Value

    'Looping through each of our output cells.
    For Each t In Range("B7:E9") 'Change these to match your real ranges.

        'Looping through each departure date/time.
        '(Only one row in your example. This can be adjusted if needed.)
        For Each x In Range("B2:E2") 'Change these to match your real ranges.
            'Check to see if our dep time corresponds to
            'the matching column in our output
            If t.Column = x.Column Then
                'If it does, then check to see what our time value is
                If x > 0 Then
                    time2 = x.Value
                    'Apply the change to the output cell.
                    t.Value = time1 - time2
                    'Exit out of this loop and move to the next output cell.
                    Exit For
                End If
            End If
            'If the columns don't match, or the x value is not a time
            'then we'll move to the next dep time (x)
        Next x
    Next t

End Sub

EDIT

I changed you worksheet to play with (see above for the new Sub). This probably does not suite your needs directly, but hopefully it will demonstrate the conept behind what I think you want to do. Please keep in mind that this code does not follow all the coding best preactices I would recommend (e.g. validating the time is actually a TIME and not some random other data type).

     A                      B                   C                   D                  E
1    LOAD_NUMBER            1                   2                   3                  4
2    DEPARTURE_TIME_DATE    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 19:30    11/12/2011 20:00                
4    Dry_Refrig 7585.1  0   10099.8 16700
6    1/4/2012 19:30

Using the sub I got this output:

    A           B             C             D             E
7   Friday      1272:00:00    1272:00:00    1272:00:00    1271:30:00
8   Saturday    1272:00:00    1272:00:00    1272:00:00    1271:30:00
9   Thursday    1272:00:00    1272:00:00    1272:00:00    1271:30:00

Nested or Inner Class in PHP

You can, like this, in PHP 7:

class User{
  public $id;
  public $name;
  public $password;
  public $Profile;
  public $History;  /*  (optional declaration, if it isn't public)  */
  public function __construct($id,$name,$password){
    $this->id=$id;
    $this->name=$name;
    $this->name=$name;
    $this->Profile=(object)[
        'get'=>function(){
          return 'Name: '.$this->name.''.(($this->History->get)());
        }
      ];
    $this->History=(object)[
        'get'=>function(){
          return ' History: '.(($this->History->track)());
        }
        ,'track'=>function(){
          return (lcg_value()>0.5?'good':'bad');
        }
      ];
  }
}
echo ((new User(0,'Lior','nyh'))->Profile->get)();

Can you create nested WITH clauses for Common Table Expressions?

I was trying to measure the time between events with the exception of what one entry that has multiple processes between the start and end. I needed this in the context of other single line processes.

I used a select with an inner join as my select statement within the Nth cte. The second cte I needed to extract the start date on X and end date on Y and used 1 as an id value to left join to put them on a single line.

Works for me, hope this helps.

cte_extract
as 
(
    select ps.Process as ProcessEvent
        , ps.ProcessStartDate 
        , ps.ProcessEndDate 
        -- select strt.*
    from dbo.tbl_some_table ps 
    inner join (select max(ProcessStatusId) ProcessStatusId 
                    from dbo.tbl_some_table 
                where Process = 'some_extract_tbl' 
                and convert(varchar(10), ProcessStartDate, 112) < '29991231'
                ) strt on strt.ProcessStatusId = ps.ProcessStatusID
), 
cte_rls
as 
(
    select 'Sample' as ProcessEvent, 
     x.ProcessStartDate, y.ProcessEndDate  from (
    select 1 as Id, ps.Process as ProcessEvent
        , ps.ProcessStartDate 
        , ps.ProcessEndDate
        -- select strt.*
    from dbo.tbl_some_table ps 
    inner join (select max(ProcessStatusId) ProcessStatusId 
                    from dbo.tbl_some_table 
                where Process = 'XX Prcss' 
                and convert(varchar(10), ProcessStartDate, 112) < '29991231'
                ) strt on strt.ProcessStatusId = ps.ProcessStatusID
    ) x
    left join (
        select 1 as Id, ps.Process as ProcessEvent
            , ps.ProcessStartDate 
            , ps.ProcessEndDate
            -- select strt.*
        from dbo.tbl_some_table ps 
        inner join (select max(ProcessStatusId) ProcessStatusId
                    from dbo.tbl_some_table 
                    where Process = 'YY Prcss Cmpltd' 
                    and convert(varchar(10), ProcessEndDate, 112) < '29991231'
                    ) enddt on enddt.ProcessStatusId = ps.ProcessStatusID
            ) y on y.Id = x.Id 
),

.... other ctes

Missing Compliance in Status when I add built for internal testing in Test Flight.How to solve?

Add following at the bottom of your Info.plist

<key>ITSAppUsesNonExemptEncryption</key>
<false/>

Visual Studio Code Tab Key does not insert a tab

As of December 2018 on macOS Mojave 10.14.2 using VSCode 1.29.1 the default keybinding for 'Toggle Tab Key Moves Focus' is set to Command+Shift+M. If you got stuck with this, using that key combo should fix the issue.

Do Command+K Command+S to pull up the Hotkeys Settings and then search for Toggle Tab Key Moves Focus or editor.action.toggleTabFocusMode if you want to change the key combo.

Memory errors and list limits?

First off, see How Big can a Python Array Get? and Numpy, problem with long arrays

Second, the only real limit comes from the amount of memory you have and how your system stores memory references. There is no per-list limit, so Python will go until it runs out of memory. Two possibilities:

  1. If you are running on an older OS or one that forces processes to use a limited amount of memory, you may need to increase the amount of memory the Python process has access to.
  2. Break the list apart using chunking. For example, do the first 1000 elements of the list, pickle and save them to disk, and then do the next 1000. To work with them, unpickle one chunk at a time so that you don't run out of memory. This is essentially the same technique that databases use to work with more data than will fit in RAM.

What is the difference between active and passive FTP?

Active Mode—The client issues a PORT command to the server signaling that it will “actively” provide an IP and port number to open the Data Connection back to the client.

Passive Mode—The client issues a PASV command to indicate that it will wait “passively” for the server to supply an IP and port number, after which the client will create a Data Connection to the server.

There are lots of good answers above, but this blog post includes some helpful graphics and gives a pretty solid explanation: https://titanftp.com/2018/08/23/what-is-the-difference-between-active-and-passive-ftp/

Use superscripts in R axis labels

It works the same way for axes: parse(text='70^o*N') will raise the o as a superscript (the *N is to make sure the N doesn't get raised too).

labelsX=parse(text=paste(abs(seq(-100, -50, 10)), "^o ", "*W", sep=""))
labelsY=parse(text=paste(seq(50,100,10), "^o ", "*N", sep=""))
plot(-100:-50, 50:100, type="n", xlab="", ylab="", axes=FALSE)
axis(1, seq(-100, -50, 10), labels=labelsX)
axis(2, seq(50, 100, 10), labels=labelsY)
box()

Is there a way to rollback my last push to Git?

First you need to determine the revision ID of the last known commit. You can use HEAD^ or HEAD~{1} if you know you need to reverse exactly one commit.

git reset --hard <revision_id_of_last_known_good_commit>
git push --force

Generate preview image from Video file?

I recommend php-ffmpeg library.

Extracting image

You can extract a frame at any timecode using the FFMpeg\Media\Video::frame method.

This code returns a FFMpeg\Media\Frame instance corresponding to the second 42. You can pass any FFMpeg\Coordinate\TimeCode as argument, see dedicated documentation below for more information.

$frame = $video->frame(FFMpeg\Coordinate\TimeCode::fromSeconds(42));
$frame->save('image.jpg');

If you want to extract multiple images from the video, you can use the following filter:

$video
    ->filters()
    ->extractMultipleFrames(FFMpeg\Filters\Video\ExtractMultipleFramesFilter::FRAMERATE_EVERY_10SEC, '/path/to/destination/folder/')
    ->synchronize();

$video
    ->save(new FFMpeg\Format\Video\X264(), '/path/to/new/file');

By default, this will save the frames as jpg images.

You are able to override this using setFrameFileType to save the frames in another format:

$frameFileType = 'jpg'; // either 'jpg', 'jpeg' or 'png'
$filter = new ExtractMultipleFramesFilter($frameRate, $destinationFolder);
$filter->setFrameFileType($frameFileType);

$video->addFilter($filter);

Removing cordova plugins from the project

  • access the folder
  • list the plugins (cordova plugin list)
  • ionic cordova plugin remove "pluginName"

Should be fine!

HTML: How to limit file upload to be only images?

HTML5 says <input type="file" accept="image/*">. Of course, never trust client-side validation: Always check again on the server-side...

Basic Ajax send/receive with node.js

Express makes this kind of stuff really intuitive. The syntax looks like below :

var app = require('express').createServer();
app.get("/string", function(req, res) {
    var strings = ["rad", "bla", "ska"]
    var n = Math.floor(Math.random() * strings.length)
    res.send(strings[n])
})
app.listen(8001)

https://expressjs.com

If you're using jQuery on the client side you can do something like this:

$.get("/string", function(string) {
    alert(string)
})

Failed to resolve: com.android.support:appcompat-v7:28.0

As @Sourabh already pointed out, you can check in the Google Maven link what are the packages that Google has listed out.

If you, like me, are prompted with a similar message to this Failed to resolve: com.android.support:appcompat-v7:28.0, it could be that you got there after upgrading the targetSdkVersion or compileSdkVersion.

What is basically happening is that the package is not being found, as the message correctly says. If you upgraded the SDK, check the Google Maven, to check what are the available versions of the package for the new SDK version that you want to upgrade to.

I had these dependencies (on version 27):

implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support:design:27.1.1'
implementation 'com.android.support:recyclerview-v7:27.1.1'
implementation 'com.android.support:cardview-v7:27.1.1'
implementation 'com.android.support:support-v4:27.1.1'

And I had to change the SDK version and the rest of the package number:

implementation 'com.android.support:appcompat-v7:28.0.0'
implementation 'com.android.support:design:28.0.0'
implementation 'com.android.support:recyclerview-v7:28.0.0'
implementation 'com.android.support:cardview-v7:28.0.0'
implementation 'com.android.support:support-v4:28.0.0'

Now the packages are found and downloaded. Since the only available package for the 28 version of the SDK is 28.0.0 at the moment of writing this.

python, sort descending dataframe with pandas

https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.sort_values.html

I don't think you should ever provide the False value in square brackets (ever), also the column values when they are more than one, then only they are provided as a list! Not like ['one'].

test = df.sort_values(by='one', ascending = False)

Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<AnonymousType#1>' to 'System.Collections.Generic.List<string>

I think the answers are below

List<string> aa = (from char c in source
                    select c.ToString() ).ToList();

List<string> aa2 = (from char c1 in source
                    from char c2 in source
                    select string.Concat(c1, ".", c2)).ToList();

Plotting images side by side using matplotlib

The problem you face is that you try to assign the return of imshow (which is an matplotlib.image.AxesImage to an existing axes object.

The correct way of plotting image data to the different axes in axarr would be

f, axarr = plt.subplots(2,2)
axarr[0,0].imshow(image_datas[0])
axarr[0,1].imshow(image_datas[1])
axarr[1,0].imshow(image_datas[2])
axarr[1,1].imshow(image_datas[3])

The concept is the same for all subplots, and in most cases the axes instance provide the same methods than the pyplot (plt) interface. E.g. if ax is one of your subplot axes, for plotting a normal line plot you'd use ax.plot(..) instead of plt.plot(). This can actually be found exactly in the source from the page you link to.

How do I find out what is hammering my SQL Server?

You can find some useful query here:

Investigating the Cause of SQL Server High CPU

For me this helped a lot:

SELECT s.session_id,
    r.status,
    r.blocking_session_id 'Blk by',
    r.wait_type,
    wait_resource,
    r.wait_time / (1000 * 60) 'Wait M',
    r.cpu_time,
    r.logical_reads,
    r.reads,
    r.writes,
    r.total_elapsed_time / (1000 * 60) 'Elaps M',
    Substring(st.TEXT,(r.statement_start_offset / 2) + 1,
    ((CASE r.statement_end_offset
WHEN -1
THEN Datalength(st.TEXT)
ELSE r.statement_end_offset
END - r.statement_start_offset) / 2) + 1) AS statement_text,
    Coalesce(Quotename(Db_name(st.dbid)) + N'.' + Quotename(Object_schema_name(st.objectid, st.dbid)) + N'.' +
    Quotename(Object_name(st.objectid, st.dbid)), '') AS command_text,
    r.command,
    s.login_name,
    s.host_name,
    s.program_name,
    s.last_request_end_time,
    s.login_time,
    r.open_transaction_count
FROM sys.dm_exec_sessions AS s
    JOIN sys.dm_exec_requests AS r
ON r.session_id = s.session_id
    CROSS APPLY sys.Dm_exec_sql_text(r.sql_handle) AS st
WHERE r.session_id != @@SPID
ORDER BY r.cpu_time desc

In the fields of status, wait_type and cpu_time you can find the most cpu consuming task that is running right now.

Error System.Data.OracleClient requires Oracle client software version 8.1.7 or greater when installs setup

Go to C:\app\insolution\product\11.2.0\client_1\BIN and find oci.dll. Right click on it -->Properties -->Under Security tab, click on Edit -->Then Click on Add Button --> Here add two new users with names IUSR and IIS_IUSRS and give them full controls. That's it.

border-radius not working

Im just highlighting part of @Ethan May answer which is

overflow: hidden;

It would most probably do the work for your case.

How can I close a browser window without receiving the "Do you want to close this window" prompt?

The browser is complaining because you're using JavaScript to close a window that wasn't opened with JavaScript, i.e. window.open('foo.html');.

How to list all users in a Linux group?

You can do it in a single command line:

cut -d: -f1,4 /etc/passwd | grep $(getent group <groupname> | cut -d: -f3) | cut -d: -f1

Above command lists all the users having groupname as their primary group

If you also want to list the users having groupname as their secondary group, use following command

getent group <groupname> | cut -d: -f4 |  tr ',' '\n'

Wait for page load in Selenium

Use:

driver.manage().timeOuts().implicitlyWait(10, TimeUnit.SECONDS);

Which means any search for the elements on the web page could take time to load. The implicitlyWait is set before throwing an exception. The TimeUnit displays whichever way you want to wait in (seconds, minutes, hours and days).

Error - "UNION operator must have an equal number of expressions" when using CTE for recursive selection

Although this an old post, I am sharing another working example.

"COLUMN COUNT AS WELL AS EACH COLUMN DATATYPE MUST MATCH WHEN 'UNION' OR 'UNION ALL' IS USED"

Let us take an example:

1:

In SQL if we write - SELECT 'column1', 'column2' (NOTE: remember to specify names in quotes) In a result set, it will display empty columns with two headers - column1 and column2

2: I share one simple instance I came across.

I had seven columns with few different datatypes in SQL. I.e. uniqueidentifier, datetime, nvarchar

My task was to retrieve comma separated result set with column header. So that when I export the data to CSV I have comma separated rows with first row as header and has respective column names.

SELECT CONVERT(NVARCHAR(36), 'Event ID') + ', ' + 
'Last Name' + ', ' + 
'First Name' + ', ' + 
'Middle Name' + ', ' + 
CONVERT(NVARCHAR(36), 'Document Type') + ', ' + 
'Event Type' + ', ' + 
CONVERT(VARCHAR(23), 'Last Updated', 126)

UNION ALL

SELECT CONVERT(NVARCHAR(36), inspectionid) + ', ' + 
       individuallastname + ', ' + 
       individualfirstname + ', ' + 
       individualmiddlename + ', ' +
       CONVERT(NVARCHAR(36), documenttype) + ', ' + 
       'I' + ', ' +
       CONVERT(VARCHAR(23), modifiedon, 126)
FROM Inspection

Above, columns 'inspectionid' & 'documenttype' has uniqueidentifer datatype and so applied CONVERT(NVARCHAR(36)). column 'modifiedon' is datetime and so applied CONVERT(NVARCHAR(23), 'modifiedon', 126).

Parallel to above 2nd SELECT query matched 1st SELECT query as per datatype of each column.

Change Primary Key

Assuming that your table name is city and your existing Primary Key is pk_city, you should be able to do the following:

ALTER TABLE city
DROP CONSTRAINT pk_city;

ALTER TABLE city
ADD CONSTRAINT pk_city PRIMARY KEY (city_id, buildtime, time);

Make sure that there are no records where time is NULL, otherwise you won't be able to re-create the constraint.

ng-repeat: access key and value for each object in array of objects

In case this is an option for you, if you put your data into object form it works the way I think you're hoping for:

$scope.steps = {
 companyName: true,
 businessType: true,
 physicalAddress: true
};

Here's a fiddle of this: http://jsfiddle.net/zMjVp/

Using Java to find substring of a bigger string using Regular Expression

the non-regex way:

String input = "FOO[BAR]", extracted;
extracted = input.substring(input.indexOf("["),input.indexOf("]"));

alternatively, for slightly better performance/memory usage (thanks Hosam):

String input = "FOO[BAR]", extracted;
extracted = input.substring(input.indexOf('['),input.lastIndexOf(']'));

Git: Could not resolve host github.com error while cloning remote repository in git

Spent a couple hours trying to fix this.

Re-connecting my wifi did the trick.

How to calculate 1st and 3rd quartiles?

Using np.percentile.

q75, q25 = np.percentile(DataFrame, [75,25])
iqr = q75 - q25

Answer from How do you find the IQR in Numpy?

Strip HTML from Text JavaScript

This should do the work on any Javascript environment (NodeJS included).

const text = `
<html lang="en">
  <head>
    <style type="text/css">*{color:red}</style>
    <script>alert('hello')</script>
  </head>
  <body><b>This is some text</b><br/><body>
</html>`;

// Remove style tags and content
text.replace(/<style[^>]*>.*<\/style>/gm, '')
    // Remove script tags and content
    .replace(/<script[^>]*>.*<\/script>/gm, '')
    // Remove all opening, closing and orphan HTML tags
    .replace(/<[^>]+>/gm, '')
    // Remove leading spaces and repeated CR/LF
    .replace(/([\r\n]+ +)+/gm, '');

How to change to an older version of Node.js

Update: December 2020 - I have updated the answer because previous one was not relevant.

Follow below steps to update your node version.

1. Install nvm For this run below command in your terminal

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.37.2/install.sh | bash

2. Install specific node version using nvm

For this run

Replace 12.14.1 with your node version

nvm install 12.14.1

Note: If you are getting error of NVM not recognised then run below command and then run above again

source ~/.nvm/nvm.sh

3. Make the installed version default

Note: Replace 12.14.1 with your installed version.

nvm alias default 12.14.1

4. Check node version

node -v

And that's it. Cheers!

How to call a JavaScript function from PHP?

you can try this one also:-

    public function PHPFunction()
    {
            echo '<script type="text/javascript">
                 test();
            </script>'; 
    }
    <script type="text/javascript">
    public function test()
    {
        alert('In test Function');
    }
    </script>

How to do tag wrapping in VS code?

With VSCode 1.47+ you can simply use OPT-w for this.

Utilizing built-in functionality to trigger emmet, this is the easiest way:

  1. Select your text/html.
  2. Option+w
  3. In the emmet window opened in the command palette, type in the tag or wrapping code you need.
  4. Enter
  5. Voila

String formatting: % vs. .format vs. string literal

To answer your first question... .format just seems more sophisticated in many ways. An annoying thing about % is also how it can either take a variable or a tuple. You'd think the following would always work:

"hi there %s" % name

yet, if name happens to be (1, 2, 3), it will throw a TypeError. To guarantee that it always prints, you'd need to do

"hi there %s" % (name,)   # supply the single argument as a single-item tuple

which is just ugly. .format doesn't have those issues. Also in the second example you gave, the .format example is much cleaner looking.

Why would you not use it?

  • not knowing about it (me before reading this)
  • having to be compatible with Python 2.5

To answer your second question, string formatting happens at the same time as any other operation - when the string formatting expression is evaluated. And Python, not being a lazy language, evaluates expressions before calling functions, so in your log.debug example, the expression "some debug info: %s"%some_infowill first evaluate to, e.g. "some debug info: roflcopters are active", then that string will be passed to log.debug().

How to make IPython notebook matplotlib plot inline

You can simulate this problem with a syntax mistake, however, %matplotlib inline won't resolve the issue.

First an example of the right way to create a plot. Everything works as expected with the imports and magic that eNord9 supplied.

df_randNumbers1 = pd.DataFrame(np.random.randint(0,100,size=(100, 6)), columns=list('ABCDEF'))

df_randNumbers1.ix[:,["A","B"]].plot.kde()

However, by leaving the () off the end of the plot type you receive a somewhat ambiguous non-error.

Erronious code:

df_randNumbers1.ix[:,["A","B"]].plot.kde

Example error:

<bound method FramePlotMethods.kde of <pandas.tools.plotting.FramePlotMethods object at 0x000001DDAF029588>>

Other than this one line message, there is no stack trace or other obvious reason to think you made a syntax error. The plot doesn't print.

Drawing a line/path on Google Maps

You can get the projection from the MapView object which is passed into the draw() method: mapv.getProjection().toPixels(gP1, p1);

In SQL, how can you "group by" in ranges?

declare @RangeWidth int

set @RangeWidth = 10

select
   Floor(Score/@RangeWidth) as LowerBound,
   Floor(Score/@RangeWidth)+@RangeWidth as UpperBound,
   Count(*)
From
   ScoreTable
group by
   Floor(Score/@RangeWidth)

Getting View's coordinates relative to the root layout

No need to calculate it manually.

Just use getGlobalVisibleRect like so:

Rect myViewRect = new Rect();
myView.getGlobalVisibleRect(myViewRect);
float x = myViewRect.left;
float y = myViewRect.top;

Also note that for the centre coordinates, rather than something like:

...
float two = (float) 2
float cx = myViewRect.left + myView.getWidth() / two;
float cy = myViewRect.top + myView.getHeight() / two;

You can just do:

float cx = myViewRect.exactCenterX();
float cy = myViewRect.exactCenterY();

jQuery .attr("disabled", "disabled") not working in Chrome

If you are using jQuery < 1.6 do this:

jQuery("input[type='text']").attr("disabled", 'disabled');

If you are using jQuery 1.6+:

jQuery("input[type='text']").prop("disabled", true);

See this question: .prop() vs .attr() for references why.

Or you can try this:

$('input:text').attr("disabled", 'disabled');

see here for info on :text

SQL Query for Logins

sp_helplogins will give you the logins along with the DBs and the rights on them.

C++ STL Vectors: Get iterator from index?

Or you can use std::advance

vector<int>::iterator i = L.begin();
advance(i, 2);

Subversion stuck due to "previous operation has not finished"?

In my case a background Java Virtual Machine instance was running, killing which cleanup was successful.

How do I get ASP.NET Web API to return JSON instead of XML using Chrome?

Using Felipe Leusin's answer for years, after a recent update of core libraries and of Json.Net, I ran into a System.MissingMethodException:SupportedMediaTypes. The solution in my case, hopefully helpful to others experiencing the same unexpected exception, is to install System.Net.Http. NuGet apparently removes it in some circumstances. After a manual installation, the issue was resolved.

How do you beta test an iphone app?

In year 2011, there's a new service out called "Test Flight", and it addresses this issue directly.

Apple has since bought TestFlight in 2014 and has integrated it into iTunes Connect and App Store Connect.

How to enter in a Docker container already running with a new TTY

I started powershell on a running microsoft/iis run as daemon using

docker exec -it <nameOfContainer> powershell

python: [Errno 10054] An existing connection was forcibly closed by the remote host

For me this problem arised while trying to connect to the SAP Hana database. When I got this error,

OperationalError: Lost connection to HANA server (ConnectionResetError(10054, 'An existing connection was forcibly closed by the remote host', None, 10054, None))

I tried to run the code for connection(mentioned below), which created that error, again and it worked.


    import pyhdb
    connection = pyhdb.connect(host="example.com",port=30015,user="user",password="secret")
    cursor = connection.cursor()
    cursor.execute("SELECT 'Hello Python World' FROM DUMMY")
    cursor.fetchone()
    connection.close()

It was because the server refused to connect. It might require you to wait for a while and try again. Try closing the Hana Studio by logging off and then logging in again. Keep running the code for a number of times.

Assert that a method was called in a Python unit test

I use Mock (which is now unittest.mock on py3.3+) for this:

from mock import patch
from PyQt4 import Qt


@patch.object(Qt.QMessageBox, 'aboutQt')
def testShowAboutQt(self, mock):
    self.win.actionAboutQt.trigger()
    self.assertTrue(mock.called)

For your case, it could look like this:

import mock
from mock import patch


def testClearWasCalled(self):
   aw = aps.Request("nv1")
   with patch.object(aw, 'Clear') as mock:
       aw2 = aps.Request("nv2", aw)

   mock.assert_called_with(42) # or mock.assert_called_once_with(42)

Mock supports quite a few useful features, including ways to patch an object or module, as well as checking that the right thing was called, etc etc.

Caveat emptor! (Buyer beware!)

If you mistype assert_called_with (to assert_called_once or assert_called_wiht) your test may still run, as Mock will think this is a mocked function and happily go along, unless you use autospec=true. For more info read assert_called_once: Threat or Menace.

In JavaScript can I make a "click" event fire programmatically for a file input element?

just use a label tag, that way you can hide the input, and make it work through its related label https://developer.mozilla.org/fr/docs/Web/HTML/Element/Label

Asking the user for input until they give a valid response

The simple solution would be:

while True:
    age = int(input("Please enter your age: "))

    if (age<=0) or (age>120):
        print('Sorry, I did not understand that.Please try again')
        continue
    else:

        if age>=18:
            print("You are able to vote in the United States!")
        else:
            print("You are not able to vote in the United States.")
        break

Explanation of above code: In order for a valid age,it should be positive and should not be more than normal physical age,say for example maximum age is 120.

Then we can ask user for age and if age input is negative or more than 120,we consider it invalid input and ask the user to try again.

Once the valid input is entered, we perform a check (using nested if-else statement) whether the age is >=18 or vice versa and print a message whether the user is eligible to vote

How would I get a cron job to run every 30 minutes?

You mention you are using OS X- I have used cronnix in the past. It's not as geeky as editing it yourself, but it helped me learn what the columns are in a jiffy. Just a thought.

Image size (Python, OpenCV)

For me the easiest way is to take all the values returned by image.shape:

height, width, channels = img.shape

if you don't want the number of channels (useful to determine if the image is bgr or grayscale) just drop the value:

height, width, _ = img.shape

Does java.util.List.isEmpty() check if the list itself is null?

No java.util.List.isEmpty() doesn't check if a list is null.

If you are using Spring framework you can use the CollectionUtils class to check if a list is empty or not. It also takes care of the null references. Following is the code snippet from Spring framework's CollectionUtils class.

public static boolean isEmpty(Collection<?> collection) {
    return (collection == null || collection.isEmpty());
}

Even if you are not using Spring, you can go on and tweak this code to add in your AppUtil class.

Retrofit 2 - Dynamic URL

You can use the encoded flag on the @Path annotation:

public interface APIService {
  @GET("{fullUrl}")
  Call<Users> getUsers(@Path(value = "fullUrl", encoded = true) String fullUrl);
}
  • This will prevent the replacement of / with %2F.
  • It will not save you from ? being replaced by %3F, however, so you still can't pass in dynamic query strings.

no default constructor exists for class

A default constructor is a constructor that either has no parameters, or if it has parameters, all the parameters have default values.

How to stop default link click behavior with jQuery

$('.update-cart').click(function(e) {
    updateCartWidget();
    e.stopPropagation();
    e.preventDefault();
});

$('.update-cart').click(function() {
    updateCartWidget();
    return false;
});

The following methods achieve the exact same thing.

Iterating over every property of an object in javascript using Prototype?

There's no need for Prototype here: JavaScript has for..in loops. If you're not sure that no one messed with Object.prototype, check hasOwnProperty() as well, ie

for(var prop in obj) {
    if(obj.hasOwnProperty(prop))
        doSomethingWith(obj[prop]);
}

How to create timer events using C++ 11?

If you are on Windows, you can use the CreateThreadpoolTimer function to schedule a callback without needing to worry about thread management and without blocking the current thread.

template<typename T>
static void __stdcall timer_fired(PTP_CALLBACK_INSTANCE, PVOID context, PTP_TIMER timer)
{
    CloseThreadpoolTimer(timer);
    std::unique_ptr<T> callable(reinterpret_cast<T*>(context));
    (*callable)();
}

template <typename T>
void call_after(T callable, long long delayInMs)
{
    auto state = std::make_unique<T>(std::move(callable));
    auto timer = CreateThreadpoolTimer(timer_fired<T>, state.get(), nullptr);
    if (!timer)
    {
        throw std::runtime_error("Timer");
    }

    ULARGE_INTEGER due;
    due.QuadPart = static_cast<ULONGLONG>(-(delayInMs * 10000LL));

    FILETIME ft;
    ft.dwHighDateTime = due.HighPart;
    ft.dwLowDateTime = due.LowPart;

    SetThreadpoolTimer(timer, &ft, 0 /*msPeriod*/, 0 /*msWindowLength*/);
    state.release();
}

int main()
{
    auto callback = []
    {
        std::cout << "in callback\n";
    };

    call_after(callback, 1000);
    std::cin.get();
}

regex pattern to match the end of a string

Should be

~/([^/]*)$~

Means: Match a / and then everything, that is not a / ([^/]*) until the end ($, "end"-anchor).

I use the ~ as delimiter, because now I don't need to escape the forward-slash /.

What does the "+=" operator do in Java?

devtop += Math.pow(x[i] - mean, 2); will add the result of the operation Math.pow(x[i] - mean, 2) to the devtop variable.

A more simple example:

int devtop = 2;
devtop += 3; // devtop now equals 5

How to drop SQL default constraint without knowing its name?

I found that this works and uses no joins:

DECLARE @ObjectName NVARCHAR(100)
SELECT @ObjectName = OBJECT_NAME([default_object_id]) FROM SYS.COLUMNS
WHERE [object_id] = OBJECT_ID('[tableSchema].[tableName]') AND [name] = 'columnName';
EXEC('ALTER TABLE [tableSchema].[tableName] DROP CONSTRAINT ' + @ObjectName)

Just make sure that columnName does not have brackets around it because the query is looking for an exact match and will return nothing if it is [columnName].

add onclick function to a submit button

I have this code:

_x000D_
_x000D_
<html>_x000D_
<head>_x000D_
<SCRIPT type=text/javascript>_x000D_
function deshabilitarBoton() {     _x000D_
    document.getElementById("boton").style.display = 'none';_x000D_
    document.getElementById("envio").innerHTML ="<br><img src='img/loading.gif' width='16' height='16' border='0'>Generando...";     _x000D_
    return true;_x000D_
} _x000D_
</SCRIPT>_x000D_
<title>untitled</title>_x000D_
</head>_x000D_
<body>_x000D_
<form name="form" action="ok.do" method="post" >_x000D_
<table>_x000D_
<tr>_x000D_
<td>Fecha inicio:</td>_x000D_
<td><input type="TEXT" name="fecha_inicio" id="fecha_inicio"  /></td>_x000D_
</tr>_x000D_
</table>_x000D_
<div id="boton">_x000D_
   <input type="submit" name="event" value="Enviar" class="button" onclick="return deshabilitarBoton()" />_x000D_
</div>_x000D_
<div id="envio">_x000D_
</div>_x000D_
</form>_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

H2 database error: Database may be already in use: "Locked by another process"

I got clue from Saman Salehi above. My usecase: Preparing REST application for client-side load balancing(running two JVM instances of REST). Here my MVC application will call this REST application that has ActiveMQ backend for DATA. I had the problem when I ran two instances of REST application in eclipse and trying to run both instances at the same time with the following configuration

spring.datasource.url=jdbc:h2:file:./Database;
spring.jpa.properties.hibernate.hbm2ddl.auto=update

After adding DB_CLOSE_ON_EXIT=FALSE;AUTO_SERVER=TRUE

spring.datasource.url=jdbc:h2:file:./Database;DB_CLOSE_ON_EXIT=FALSE;AUTO_SERVER=TRUE

Both instances are running and showing in Eureka dasboard.

Don't close the database when the VM exits : jdbc:h2:;DB_CLOSE_ON_EXIT=FALSE

Multiple processes can access the same database without having to start the server manually ;AUTO_SERVER=TRUE

Further reading: http://www.h2database.com/html/features.html

set background color: Android

This question is a old one but it can help for others too.

Try this :

    li.setBackgroundColor(getResources().getColor(R.color.blue));

    or

    li.setBackgroundColor(getResources().getColor(android.R.color.red));

    or

    li.setBackgroundColor(Color.rgb(226, 11, 11));


    or
    li.setBackgroundColor(Color.RED)

How to set image for bar button with swift?

If your UIBarButtonItem is already allocated like in a storyboard. (printBtn)

    let btn = UIButton(frame: CGRect(x: 0, y: 0, width: 30, height: 30))
    btn.setImage(UIImage(named: Constants.ImageName.print)?.withRenderingMode(.alwaysTemplate), for: .normal)
    btn.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(handlePrintPress(tapGesture:))))
    printBtn.customView = btn

How to set custom JsonSerializerSettings for Json.NET in ASP.NET Web API?

You can customize the JsonSerializerSettings by using the Formatters.JsonFormatter.SerializerSettings property in the HttpConfiguration object.

For example, you could do that in the Application_Start() method:

protected void Application_Start()
{
    HttpConfiguration config = GlobalConfiguration.Configuration;
    config.Formatters.JsonFormatter.SerializerSettings.Formatting =
        Newtonsoft.Json.Formatting.Indented;
}

Visual Studio Code how to resolve merge conflicts with git?

For VS Code 1.38 or if you could not find any "lightbulb" button. Pay close attention to the greyed out text above the conflicts; there is a list of actions you can take.

Makefile, header dependencies

Most answers are surprisingly complicated or erroneous. However simple and robust examples have been posted elsewhere [codereview]. Admittedly the options provided by the gnu preprocessor are a bit confusing. However, the removal of all directories from the build target with -MM is documented and not a bug [gpp]:

By default CPP takes the name of the main input file, deletes any directory components and any file suffix such as ‘.c’, and appends the platform's usual object suffix.

The (somewhat newer) -MMD option is probably what you want. For completeness an example of a makefile that supports multiple src dirs and build dirs with some comments. For a simple version without build dirs see [codereview].

CXX = clang++
CXX_FLAGS = -Wfatal-errors -Wall -Wextra -Wpedantic -Wconversion -Wshadow

# Final binary
BIN = mybin
# Put all auto generated stuff to this build dir.
BUILD_DIR = ./build

# List of all .cpp source files.
CPP = main.cpp $(wildcard dir1/*.cpp) $(wildcard dir2/*.cpp)

# All .o files go to build dir.
OBJ = $(CPP:%.cpp=$(BUILD_DIR)/%.o)
# Gcc/Clang will create these .d files containing dependencies.
DEP = $(OBJ:%.o=%.d)

# Default target named after the binary.
$(BIN) : $(BUILD_DIR)/$(BIN)

# Actual target of the binary - depends on all .o files.
$(BUILD_DIR)/$(BIN) : $(OBJ)
    # Create build directories - same structure as sources.
    mkdir -p $(@D)
    # Just link all the object files.
    $(CXX) $(CXX_FLAGS) $^ -o $@

# Include all .d files
-include $(DEP)

# Build target for every single object file.
# The potential dependency on header files is covered
# by calling `-include $(DEP)`.
$(BUILD_DIR)/%.o : %.cpp
    mkdir -p $(@D)
    # The -MMD flags additionaly creates a .d file with
    # the same name as the .o file.
    $(CXX) $(CXX_FLAGS) -MMD -c $< -o $@

.PHONY : clean
clean :
    # This should remove all generated files.
    -rm $(BUILD_DIR)/$(BIN) $(OBJ) $(DEP)

This method works because if there are multiple dependency lines for a single target, the dependencies are simply joined, e.g.:

a.o: a.h
a.o: a.c
    ./cmd

is equivalent to:

a.o: a.c a.h
    ./cmd

as mentioned at: Makefile multiple dependency lines for a single target?

'Access-Control-Allow-Origin' issue when API call made from React (Isomorphic app)

        //install cors using terminal/command  
        $ npm install cors

        //If your using express in your node server just add
        var cors = require('cors');
        app.use(cors())


       //and re-run the server, your problem is rectified][1]][1]
       **If you won't be understood then see below image**

https://i.stack.imgur.com/Qeqmc.png

How to set Java environment path in Ubuntu

You can install the default Ubuntu(17.10) java from apt:

sudo apt install openjdk-8-jdk-headless 

And it will set the PATH for you, if instead you need to install specific version of Java you can follow this YouTube

How to detect responsive breakpoints of Twitter Bootstrap 3 using JavaScript?

Why not just use jQuery to detect the current css width of the bootstrap container class?

ie..

if( parseInt($('#container').css('width')) > 1200 ){
  // do something for desktop screens
}

You could also use $(window).resize() to prevent your layout from "soiling the bed" if someone resizes the browser window.

R Language: How to print the first or last rows of a data set?

If you want to print the last 10 lines, use

tail(dataset, 10)

for the first 10, you could also do

head(dataset, 10)

How to return multiple rows from the stored procedure? (Oracle PL/SQL)

You may use Oracle pipelined functions

Basically, when you would like a PLSQL (or java or c) routine to be the «source» of data -- instead of a table -- you would use a pipelined function.

Simple Example - Generating Some Random Data
How could you create N unique random numbers depending on the input argument?

create type array
as table of number;


create function  gen_numbers(n in number default null)
return array
PIPELINED
as
begin
  for i in 1 .. nvl(n,999999999)
  loop
     pipe row(i);
 end loop;
 return;
end;

Suppose we needed three rows for something. We can now do that in one of two ways:

select * from TABLE(gen_numbers(3));

COLUMN_VALUE


       1
       2
       3

or

select * from TABLE(gen_numbers)
 where rownum <= 3;

COLUMN_VALUE


       1
       2
       3

pipelied Functions1 pipelied Functions2

how to use a like with a join in sql?

Using conditional criteria in a join is definitely different than the Where clause. The cardinality between the tables can create differences between Joins and Where clauses.

For example, using a Like condition in an Outer Join will keep all records in the first table listed in the join. Using the same condition in the Where clause will implicitly change the join to an Inner join. The record has to generally be present in both tables to accomplish the conditional comparison in the Where clause.

I generally use the style given in one of the prior answers.

tbl_A as ta
    LEFT OUTER JOIN tbl_B AS tb
            ON ta.[Desc] LIKE '%' + tb.[Desc] + '%'

This way I can control the join type.

Maven Installation OSX Error Unsupported major.minor version 51.0

The problem is because you haven't set JAVA_HOME in Mac properly. In order to do that, you should do set it like this:

export JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_40.jdk/Contents/Home

In my case my JDK installation is jdk1.8.0_40, make sure you type yours.

Then you can use maven commands.

Regards!

How to disable Paste (Ctrl+V) with jQuery?

The following code will disable cut, copy and paste from full page.

$(document).ready(function () {
   $('body').bind('cut copy paste', function (e) {
      e.preventDefault();
   });
});

The full tutorial and working demo can be found from here - Disable cut, copy and paste using jQuery

How can I tell gcc not to inline a function?

Use the noinline attribute:

int func(int arg) __attribute__((noinline))
{
}

You should probably use it both when you declare the function for external use and when you write the function.

R memory management / cannot allocate vector of size n Mb

Here is a presentation on this topic that you might find interesting:

http://www.bytemining.com/2010/08/taking-r-to-the-limit-part-ii-large-datasets-in-r/

I haven't tried the discussed things myself, but the bigmemory package seems very useful

best way to get folder and file list in Javascript

In my project I use this function for getting huge amount of files. It's pretty fast (put require("FS") out to make it even faster):

var _getAllFilesFromFolder = function(dir) {

    var filesystem = require("fs");
    var results = [];

    filesystem.readdirSync(dir).forEach(function(file) {

        file = dir+'/'+file;
        var stat = filesystem.statSync(file);

        if (stat && stat.isDirectory()) {
            results = results.concat(_getAllFilesFromFolder(file))
        } else results.push(file);

    });

    return results;

};

usage is clear:

_getAllFilesFromFolder(__dirname + "folder");

How can I convert a dictionary into a list of tuples?

since no one else did, I'll add py3k versions:

>>> d = { 'a': 1, 'b': 2, 'c': 3 }
>>> list(d.items())
[('a', 1), ('c', 3), ('b', 2)]
>>> [(v, k) for k, v in d.items()]
[(1, 'a'), (3, 'c'), (2, 'b')]

JavaScript replace \n with <br />

Use a regular expression for .replace().:

messagetoSend = messagetoSend.replace(/\n/g, "<br />");

If those linebreaks were made by windows-encoding, you will also have to replace the carriage return.

messagetoSend = messagetoSend.replace(/\r\n/g, "<br />");

Ajax Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource

Add the below code to your .htaccess

Header set Access-Control-Allow-Origin *

It works for me.

Thanks

How to implement 2D vector array?

If you know the (maximum) number of rows and columns beforehand, you can use resize() to initialize a vector of vectors and then modify (and access) elements with operator[]. Example:

int no_of_cols = 5;
int no_of_rows = 10;
int initial_value = 0;

std::vector<std::vector<int>> matrix;
matrix.resize(no_of_rows, std::vector<int>(no_of_cols, initial_value));

// Read from matrix.
int value = matrix[1][2];

// Save to matrix.
matrix[3][1] = 5;

Another possibility is to use just one vector and split the id in several variables, access like vector[(row * columns) + column].

How can I find all *.js file in directory recursively in Linux?

If you just want the list, then you should ask here: http://unix.stackexchange.com

The answer is: cd / && find -name *.js

If you want to implement this, you have to specify the language.

How to read a HttpOnly cookie using JavaScript

Httponly cookies' purpose is being inaccessible by script, so you CAN NOT.

Indentation shortcuts in Visual Studio

Visual studio’s smart indenting does automatically indenting, but we can select a block or all the code for indentation.

  1. Select all the code: Ctrl+a

  2. Use either of the two ways to indentation the code:

    • Shift+Tab,

    • Ctrl+k+f.

Threading pool similar to the multiprocessing Pool?

There is no built in thread based pool. However, it can be very quick to implement a producer/consumer queue with the Queue class.

From: https://docs.python.org/2/library/queue.html

from threading import Thread
from Queue import Queue
def worker():
    while True:
        item = q.get()
        do_work(item)
        q.task_done()

q = Queue()
for i in range(num_worker_threads):
     t = Thread(target=worker)
     t.daemon = True
     t.start()

for item in source():
    q.put(item)

q.join()       # block until all tasks are done

How do I add a user when I'm using Alpine as a base image?

The commands are adduser and addgroup.

Here's a template for Docker you can use in busybox environments (alpine) as well as Debian-based environments (Ubuntu, etc.):

ENV USER=docker
ENV UID=12345
ENV GID=23456

RUN adduser \
    --disabled-password \
    --gecos "" \
    --home "$(pwd)" \
    --ingroup "$USER" \
    --no-create-home \
    --uid "$UID" \
    "$USER"

Note the following:

  • --disabled-password prevents prompt for a password
  • --gecos "" circumvents the prompt for "Full Name" etc. on Debian-based systems
  • --home "$(pwd)" sets the user's home to the WORKDIR. You may not want this.
  • --no-create-home prevents cruft getting copied into the directory from /etc/skel

The usage description for these applications is missing the long flags present in the code for adduser and addgroup.

The following long-form flags should work both in alpine as well as debian-derivatives:

adduser

BusyBox v1.28.4 (2018-05-30 10:45:57 UTC) multi-call binary.

Usage: adduser [OPTIONS] USER [GROUP]

Create new user, or add USER to GROUP

        --home DIR           Home directory
        --gecos GECOS        GECOS field
        --shell SHELL        Login shell
        --ingroup GRP        Group (by name)
        --system             Create a system user
        --disabled-password  Don't assign a password
        --no-create-home     Don't create home directory
        --uid UID            User id

One thing to note is that if --ingroup isn't set then the GID is assigned to match the UID. If the GID corresponding to the provided UID already exists adduser will fail.

addgroup

BusyBox v1.28.4 (2018-05-30 10:45:57 UTC) multi-call binary.

Usage: addgroup [-g GID] [-S] [USER] GROUP

Add a group or add a user to a group

        --gid GID  Group id
        --system   Create a system group

I discovered all of this while trying to write my own alternative to the fixuid project for running containers as the hosts UID/GID.

My entrypoint helper script can be found on GitHub.

The intent is to prepend that script as the first argument to ENTRYPOINT which should cause Docker to infer UID and GID from a relevant bind mount.

An environment variable "TEMPLATE" may be required to determine where the permissions should be inferred from.

(At the time of writing I don't have documentation for my script. It's still on the todo list!!)

rbenv not changing ruby version

I just found this same problem. What I did was uninstall rbenv (via homebrew) and reinstall it. I also added

if which rbenv > /dev/null; then eval "$(rbenv init -)"; fi

into ~/.bash_profile when I reinstalled rbenv. Works perfectly now.

Best way to convert an ArrayList to a string

In Java 8 or later:

String listString = String.join(", ", list);

In case the list is not of type String, a joining collector can be used:

String listString = list.stream().map(Object::toString)
                        .collect(Collectors.joining(", "));

How to write LDAP query to test if user is member of a group?

I would add one more thing to Marc's answer: The memberOf attribute can't contain wildcards, so you can't say something like "memberof=CN=SPS*", and expect it to find all groups that start with "SPS".

Laravel: Validation unique on update

For unique rule in the controller - which obviously will be different for the store method and the update method, I usually make a function within the controller for rules which will return an array of rules.

protected function rules($request)
{
    $commonRules = [
        'first_name' => "required",
        'last_name' => "required",
        'password' => "required|min:6|same:password_confirm",
        'password_confirm' => "required:min:6|same:password",
        'password_current' => "required:min:6"
    ];

    $uniqueRules = $request->id

          //update
        ? ['email_address' => ['required', 'email', 'unique:users,email' . $request->get('id')]]

          //store
        : ['email_address' => ['required', 'email', 'unique:users,email']];


    return array_merge($commonRules, $uinqueRules);
}

Then in the respective store and update methods

$validatedData = $request->validate($this->rules($request));

This saves from defining two different rule sets for store and update methods.

If you can afford to compromise a bit on readability, it can also be

protected function rules($request)
{
    return [
        'first_name' => "required",
        'last_name' => "required",
        'password' => "required|min:6|same:password_confirm",
        'password_confirm' => "required:min:6|same:password",
        'password_current' => "required:min:6",
        'email_address' => ['required', 'email', 'unique:users,email' . $request->id ?: null]
    ];
}

ESLint not working in VS Code?

For me, i did accidentally disable ESLint when some prompt was shown by it.

Doing below steps fixed it for me

  1. Shift + Command + P and select ESLint: Disabled ESLint
  2. Close vscode
  3. Shift + Command + P and select ESLint: Show Output Channel

Do subclasses inherit private fields?

Ok, this is a very interesting problem I researched a lot and came to a conclusion that private members of a superclass are indeed available (but not accessible) in the subclass's objects. To prove this, here is a sample code with a parent class and a child class and I am writing child class object to a txt file and reading a private member named 'bhavesh' in the file, hence proving it is indeed available in the child class but not accessible due to the access modifier.

import java.io.Serializable;
public class ParentClass implements Serializable {
public ParentClass() {

}

public int a=32131,b,c;

private int bhavesh=5555,rr,weq,refw;
}

import java.io.*;
import java.io.Serializable;
public class ChildClass extends ParentClass{
public ChildClass() {
super();
}

public static void main(String[] args) {
ChildClass childObj = new ChildClass();
ObjectOutputStream oos;
try {
        oos = new ObjectOutputStream(new FileOutputStream("C:\\MyData1.txt"));
        oos.writeObject(childObj); //Writing child class object and not parent class object
        System.out.println("Writing complete !");
    } catch (IOException e) {
    }


}
}

Open MyData1.txt and search for the private member named 'bhavesh'. Please let me know what you guys think.

How can I develop for iPhone using a Windows development machine?

You can use Sentenza for make applications for iPhone, on Windows. Tested with success. It's not a solution but a good alternative !

SQL Greater than, Equal to AND Less Than

If start time is a datetime type then you can use something like

SELECT BookingId, StartTime
FROM Booking
WHERE StartTime >= '2012-03-08 00:00:00.000' 
AND StartTime <= '2012-03-08 01:00:00.000'

Obviously you would want to use your own values for the times but this should give you everything in that 1 hour period inclusive of both the upper and lower limit.

You can use the GETDATE() function to get todays current date.

How to use PDO to fetch results array in PHP?

There are three ways to fetch multiple rows returned by PDO statement.

The simplest one is just to iterate over PDOStatement itself:

$stmt = $pdo->prepare("SELECT * FROM auction WHERE name LIKE ?")
$stmt->execute(array("%$query%"));
// iterating over a statement
foreach($stmt as $row) {
    echo $row['name'];
}

another one is to fetch rows using fetch() method inside a familiar while statement:

$stmt = $pdo->prepare("SELECT * FROM auction WHERE name LIKE ?")
$stmt->execute(array("%$query%"));
// using while
while($row = $stmt->fetch()) {
    echo $row['name'];
}

but for the modern web application we should have our datbase iteractions separated from output and thus the most convenient method would be to fetch all rows at once using fetchAll() method:

$stmt = $pdo->prepare("SELECT * FROM auction WHERE name LIKE ?")
$stmt->execute(array("%$query%"));
// fetching rows into array
$data = $stmt->fetchAll();

or, if you need to preprocess some data first, use the while loop and collect the data into array manually

$result = [];
$stmt = $pdo->prepare("SELECT * FROM auction WHERE name LIKE ?")
$stmt->execute(array("%$query%"));
// using while
while($row = $stmt->fetch()) {
    $result[] = [
        'newname' => $row['oldname'],
        // etc
    ];
}

and then output them in a template:

<ul>
<?php foreach($data as $row): ?>
    <li><?=$row['name']?></li>
<?php endforeach ?>
</ul>

Note that PDO supports many sophisticated fetch modes, allowing fetchAll() to return data in many different formats.

MySQL pivot table query with dynamic columns

The only way in MySQL to do this dynamically is with Prepared statements. Here is a good article about them:

Dynamic pivot tables (transform rows to columns)

Your code would look like this:

SET @sql = NULL;
SELECT
  GROUP_CONCAT(DISTINCT
    CONCAT(
      'MAX(IF(pa.fieldname = ''',
      fieldname,
      ''', pa.fieldvalue, NULL)) AS ',
      fieldname
    )
  ) INTO @sql
FROM product_additional;

SET @sql = CONCAT('SELECT p.id
                    , p.name
                    , p.description, ', @sql, ' 
                   FROM product p
                   LEFT JOIN product_additional AS pa 
                    ON p.id = pa.id
                   GROUP BY p.id');

PREPARE stmt FROM @sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;

See Demo

NOTE: GROUP_CONCAT function has a limit of 1024 characters. See parameter group_concat_max_len

Stuck while installing Visual Studio 2015 (Update for Microsoft Windows (KB2999226))

I faced this problem after installing clean Windows 7 Ultimate 64 bit OS,

When I search about KB2999226 install fails during Visual Studio I also saw that I couldn't install any other updates.

By the way, I found a solution. When formatting some PCs with ( maybe ) partly corrupted bootable media, first Update for windows not completely installed.

As a solution;

1- Disable update for windows from Control Panel.

2- Restart your pc.

3- Install KB3102810 windows update. ( First update for Windows )

Microsoft TR links;

( 64 bit ) https://www.microsoft.com/tr-TR/download/details.aspx?id=49540

( 32 bit ) https://www.microsoft.com/tr-TR/download/details.aspx?id=49542

4- Restart your pc via finished setup.

5- Try getting updates, or manually setup KB2999226.

I could install this way.

Have a nice days.

C# how to use enum with switch

All the other answers are correct, but you also need to call your method correctly:

Calculate(5, 5, Operator.PLUS))

And since you use int for left and right, the result will be int as well (3/2 will result in 1). you could cast to double before calculating the result or modify your parameters to accept double

What is the difference between hg forget and hg remove?

If you use "hg remove b" against a file with "A" status, which means it has been added but not commited, Mercurial will respond:

  not removing b: file has been marked for add (use forget to undo)

This response is a very clear explication of the difference between remove and forget.

My understanding is that "hg forget" is for undoing an added but not committed file so that it is not tracked by version control; while "hg remove" is for taking out a committed file from version control.

This thread has a example for using hg remove against files of 7 different types of status.

How can I add JAR files to the web-inf/lib folder in Eclipse?

Pasting the jar files in WebContent\WEB-INF\lib via the file system was the only way it worked for me.

They then appeared under the Deployed Resources and WebContent lib sub-folders.

When I looked, the build path had the jars in the Web App Libraries and everything built and ran fine.

How to set environment via `ng serve` in Angular 6

Use this command for Angular 6 to build

ng build --prod --configuration=dev

Chrome extension: accessing localStorage in content script

Sometimes it may be better to use chrome.storage API. It's better then localStorage because you can:

  • store information from your content script without the need for message passing between content script and extension;
  • store your data as JavaScript objects without serializing them to JSON (localStorage only stores strings).

Here's a simple code demonstrating the use of chrome.storage. Content script gets the url of visited page and timestamp and stores it, popup.js gets it from storage area.

content_script.js

(function () {
    var visited = window.location.href;
    var time = +new Date();
    chrome.storage.sync.set({'visitedPages':{pageUrl:visited,time:time}}, function () {
        console.log("Just visited",visited)
    });
})();

popup.js

(function () {
    chrome.storage.onChanged.addListener(function (changes,areaName) {
        console.log("New item in storage",changes.visitedPages.newValue);
    })
})();

"Changes" here is an object that contains old and new value for a given key. "AreaName" argument refers to name of storage area, either 'local', 'sync' or 'managed'.

Remember to declare storage permission in manifest.json.

manifest.json

...
"permissions": [
    "storage"
 ],
...

Remove a data connection from an Excel 2010 spreadsheet in compatibility mode

I manage to solve this in excel 97-2003, in a file with .xls extension this way: I went to the page where I had the linked data, with the cursor over the imported data table, go to tab Design --> External Data Table --> Unlink Unlink all tables (conections), delete all conections in Data --> Conections --> Conections save your work and done! regards, Dan

How do include paths work in Visual Studio?

This answer will be useful for those who use a non-standard IDE (i.e. Qt Creator).

There are at least two non-intrusive ways to pass additional include paths to Visual Studio's cl.exe via environment variables:

  • Set INCLUDE environment variable to ;-separated list of all include paths. It overrides all includes, inclusive standard library ones. Not recommended.
  • Set CL environment variable to the following value: /I C:\Lib\VulkanMemoryAllocator\src /I C:\Lib\gli /I C:\Lib\gli\external, where each argument of /I key is additional include path.

I successfully use the last one.

How can I write a regex which matches non greedy?

The non-greedy ? works perfectly fine. It's just that you need to select dot matches all option in the regex engines (regexpal, the engine you used, also has this option) you are testing with. This is because, regex engines generally don't match line breaks when you use .. You need to tell them explicitly that you want to match line-breaks too with .

For example,

<img\s.*?>

works fine!

Check the results here.

Also, read about how dot behaves in various regex flavours.

How to configure welcome file list in web.xml

You need to put the JSP file in /index.jsp instead of in /WEB-INF/jsp/index.jsp. This way the whole servlet is superflous by the way.

WebContent
 |-- META-INF
 |-- WEB-INF
 |    `-- web.xml
 `-- index.jsp

If you're absolutely positive that you need to invoke a servlet this strange way, then you should map it on an URL pattern of /index.jsp instead of /index. You only need to change it to get the request dispatcher from request instead of from config and get rid of the whole init() method.

In case you actually intend to have a "home page servlet" (and thus not a welcome file — which has an entirely different purpose; namely the default file which sould be served when a folder is being requested, which is thus not specifically the root folder), then you should be mapping the servlet on the empty string URL pattern.

<servlet-mapping>
    <servlet-name>index</servlet-name>
    <url-pattern></url-pattern>
</servlet-mapping>

See also Difference between / and /* in servlet mapping url pattern.

What does a bitwise shift (left or right) do and what is it used for?

Here is an applet where you can exercise some bit-operations, including shifting.

You have a collection of bits, and you move some of them beyond their bounds:

1111 1110 << 2
1111 1000

It is filled from the right with fresh zeros. :)

0001 1111 >> 3
0000 0011

Filled from the left. A special case is the leading 1. It often indicates a negative value - depending on the language and datatype. So often it is wanted, that if you shift right, the first bit stays as it is.

1100 1100 >> 1
1110 0110

And it is conserved over multiple shifts:

1100 1100 >> 2
1111 0011

If you don't want the first bit to be preserved, you use (in Java, Scala, C++, C as far as I know, and maybe more) a triple-sign-operator:

1100 1100 >>> 1
0110 0110

There isn't any equivalent in the other direction, because it doesn't make any sense - maybe in your very special context, but not in general.

Mathematically, a left-shift is a *=2, 2 left-shifts is a *=4 and so on. A right-shift is a /= 2 and so on.

How can I open a URL in Android's web browser from my application?

Basic Introduction:

https:// is using that one into the "code" so that no one in between can read them. This keeps your information safe from hackers.

http:// is using just sharing purpose, it's not secured.

About Your Problem:
XML designing:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.sridhar.sharedpreferencesstackoverflow.MainActivity">
   <LinearLayout
       android:orientation="horizontal"
       android:background="#228b22"
       android:layout_weight="1"
       android:layout_width="match_parent"
       android:layout_height="0dp">
      <Button
          android:id="@+id/normal_search"
          android:text="secure Search"
          android:onClick="secure"
          android:layout_weight="1"
          android:layout_width="0dp"
          android:layout_height="wrap_content" />
      <Button
          android:id="@+id/secure_search"
          android:text="Normal Search"
          android:onClick="normal"
          android:layout_weight="1"
          android:layout_width="0dp"
          android:layout_height="wrap_content" />
   </LinearLayout>

   <LinearLayout
       android:layout_weight="9"
       android:id="@+id/button_container"
       android:layout_width="match_parent"
       android:layout_height="0dp"
       android:orientation="horizontal">

      <WebView
          android:id="@+id/webView1"
          android:layout_width="match_parent"
          android:layout_height="match_parent" />

   </LinearLayout>
</LinearLayout>

Activity Designing:

public class MainActivity extends Activity {
    //securely open the browser
    public String Url_secure="https://www.stackoverflow.com";
    //normal purpouse
    public String Url_normal="https://www.stackoverflow.com";

    WebView webView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        webView=(WebView)findViewById(R.id.webView1);

    }
    public void secure(View view){
        webView.setWebViewClient(new SecureSearch());
        webView.getSettings().setLoadsImagesAutomatically(true);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
        webView.loadUrl(Url_secure);
    }
    public void normal(View view){
        webView.setWebViewClient(new NormalSearch());
        webView.getSettings().setLoadsImagesAutomatically(true);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
        webView.loadUrl(Url_normal);

    }
    public class SecureSearch extends WebViewClient{
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String Url_secure) {
            view.loadUrl(Url_secure);
            return true;
        }
    }
    public class NormalSearch extends WebViewClient{
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String Url_normal) {
            view.loadUrl(Url_normal);
            return true;
        }
    }
}

Android Manifest.Xml permissions:

<uses-permission android:name="android.permission.INTERNET"/>

You face Problems when implementing this:

  1. getting The Manifest permissions
  2. excess space's between url
  3. Check your url's correct or not

Best way to convert strings to symbols in hash

Facets' Hash#deep_rekey is also a good option, especially:

  • if you find use for other sugar from facets in your project,
  • if you prefer code readability over cryptical one-liners.

Sample:

require 'facets/hash/deep_rekey'
my_hash = YAML.load_file('yml').deep_rekey

How to commit my current changes to a different branch in Git

  1. git checkout my_other_branch
  2. git add my_file my_other_file
  3. git commit -m

And provide your commit message.

Making the iPhone vibrate

In iOS 10, and on newer iPhones, you can also use haptic API. This haptic feedback is softer than the AudioToolbox API.

For your GAME OVER scenario, a heavy UI impact feedback should be suitable.

UIImpactFeedbackGenerator(style: .heavy).impactOccurred()

You could use the other haptic feedback styles.

HTML5 Local storage vs. Session storage

The only difference is that localStorage has a different expiration time, sessionStorage will only be accessible while and by the window that created it is open.
localStorage lasts until you delete it or the user deletes it.
Lets say that you wanted to save a login username and password you would want to use sessionStorageover localStorage for security reasons (ie. another person accessing their account at a later time).
But if you wanted to save a user's settings on their machine you would probably want localStorage. All in all:

localStorage - use for long term use.
sessionStorage - use when you need to store somthing that changes or somthing temporary

Can I write or modify data on an RFID tag?

We have recently started looking into RFID solutions at my work place and we found a cheap solution for testing purposes.

One of the units from here:

http://www.sdid.com/products.shtml

Plugs into any windows mobile device with an SD slot and allows reading / writing. There is also a development kit to get you on your way with your own apps.

Hope this helps

TypeError: Converting circular structure to JSON in nodejs

TypeError: Converting circular structure to JSON in nodejs: This error can be seen on Arangodb when using it with Node.js, because storage is missing in your database. If the archive is created under your database, check in the Aurangobi web interface.

How to select the last record of a table in SQL?

Without any further information, which Database etc the best we can do is something like

Sql Server

SELECT TOP 1 * FROM Table ORDER BY ID DESC

MySql

SELECT * FROM Table ORDER BY ID DESC LIMIT 1

How to round a number to significant figures in Python

%g in string formatting will format a float rounded to some number of significant figures. It will sometimes use 'e' scientific notation, so convert the rounded string back to a float then through %s string formatting.

>>> '%s' % float('%.1g' % 1234)
'1000'
>>> '%s' % float('%.1g' % 0.12)
'0.1'
>>> '%s' % float('%.1g' % 0.012)
'0.01'
>>> '%s' % float('%.1g' % 0.062)
'0.06'
>>> '%s' % float('%.1g' % 6253)
'6000.0'
>>> '%s' % float('%.1g' % 1999)
'2000.0'

Visual c++ can't open include file 'iostream'

I had this exact same problem in VS 2015. It looks like as of VS 2010 and later you need to include #include "stdafx.h" in all your projects.

#include "stdafx.h"
#include <iostream>
using namespace std;

The above worked for me. The below did not:

#include <iostream>
using namespace std;

This also failed:

#include <iostream>
using namespace std;
#include "stdafx.h"

How to check if the request is an AJAX request with PHP

You could try using a $_SESSION variable to make sure that a request was made from a browser. Otherwise, you could have the request sent through a database or file [server-side].

Encoding conversion in java

I would just like to add that if the String is originally encoded using the wrong encoding it might be impossible to change it to another encoding without errors. The question does not state that the conversion here is made from wrong encoding to correct encoding but I personally stumbled to this question just because of this situation so just a heads up for others as well.

This answer in other question gives an explanation why the conversion does not always yield correct results https://stackoverflow.com/a/2623793/4702806

How to convert a column number (e.g. 127) into an Excel column (e.g. AA)

In Delphi (Pascal):

function GetExcelColumnName(columnNumber: integer): string;
var
  dividend, modulo: integer;
begin
  Result := '';
  dividend := columnNumber;
  while dividend > 0 do begin
    modulo := (dividend - 1) mod 26;
    Result := Chr(65 + modulo) + Result;
    dividend := (dividend - modulo) div 26;
  end;
end;

How to check if command line tools is installed

Open your terminal and check to see if you have Xcode installed already with this:

xcode-select -p

in return, if you get this:

/Library/Developer/CommandLineTools

That means you have that Xcode is installed.

Another way you can check would you if you have "HomeBrew" installed you can use the following command to see if you have Xcode and the version:

brew config

And finally, if you don't have the Xcode follow this link to download the Xcode from the Appstore. Xcode from the App Store.

Good Luck.

Gradle Build Android Project "Could not resolve all dependencies" error

Go to wherever you installed Android Studio (for me it's under C:\Users\username\AppData\Local\Android\android-studio\) and open sdk\tools, then run android.bat. From here, update and download any missing build-tools and make sure you update the Android Support Repository and Android Support Library under Extras. Restart Android Studio after the SDK Manager finishes.

It seems that Android Studio completely ignores any installed Android SDK files and keeps a copy of its own. After running an update, everything compiled successfully for me using compile com.android.support:appcompat-v7:18.0.+

Changing plot scale by a factor in matplotlib

To set the range of the x-axis, you can use set_xlim(left, right), here are the docs

Update:

It looks like you want an identical plot, but only change the 'tick values', you can do that by getting the tick values and then just changing them to whatever you want. So for your need it would be like this:

ticks = your_plot.get_xticks()*10**9
your_plot.set_xticklabels(ticks)

How to import Google Web Font in CSS file?

<link rel="stylesheet" href="//fonts.googleapis.com/css?family=Open+Sans:300,400,600,700&amp;lang=en" />

Better to not use @import. Just use the link element, as shown above, in your layout's head.

How to calculate the intersection of two sets?

Use the retainAll() method of Set:

Set<String> s1;
Set<String> s2;
s1.retainAll(s2); // s1 now contains only elements in both sets

If you want to preserve the sets, create a new set to hold the intersection:

Set<String> intersection = new HashSet<String>(s1); // use the copy constructor
intersection.retainAll(s2);

The javadoc of retainAll() says it's exactly what you want:

Retains only the elements in this set that are contained in the specified collection (optional operation). In other words, removes from this set all of its elements that are not contained in the specified collection. If the specified collection is also a set, this operation effectively modifies this set so that its value is the intersection of the two sets.

How to get the caret column (not pixels) position in a textarea, in characters, from the start?

Updated 5 September 2010

Seeing as everyone seems to get directed here for this issue, I'm adding my answer to a similar question, which contains the same code as this answer but with full background for those who are interested:

IE's document.selection.createRange doesn't include leading or trailing blank lines

To account for trailing line breaks is tricky in IE, and I haven't seen any solution that does this correctly, including any other answers to this question. It is possible, however, using the following function, which will return you the start and end of the selection (which are the same in the case of a caret) within a <textarea> or text <input>.

Note that the textarea must have focus for this function to work properly in IE. If in doubt, call the textarea's focus() method first.

function getInputSelection(el) {
    var start = 0, end = 0, normalizedValue, range,
        textInputRange, len, endRange;

    if (typeof el.selectionStart == "number" && typeof el.selectionEnd == "number") {
        start = el.selectionStart;
        end = el.selectionEnd;
    } else {
        range = document.selection.createRange();

        if (range && range.parentElement() == el) {
            len = el.value.length;
            normalizedValue = el.value.replace(/\r\n/g, "\n");

            // Create a working TextRange that lives only in the input
            textInputRange = el.createTextRange();
            textInputRange.moveToBookmark(range.getBookmark());

            // Check if the start and end of the selection are at the very end
            // of the input, since moveStart/moveEnd doesn't return what we want
            // in those cases
            endRange = el.createTextRange();
            endRange.collapse(false);

            if (textInputRange.compareEndPoints("StartToEnd", endRange) > -1) {
                start = end = len;
            } else {
                start = -textInputRange.moveStart("character", -len);
                start += normalizedValue.slice(0, start).split("\n").length - 1;

                if (textInputRange.compareEndPoints("EndToEnd", endRange) > -1) {
                    end = len;
                } else {
                    end = -textInputRange.moveEnd("character", -len);
                    end += normalizedValue.slice(0, end).split("\n").length - 1;
                }
            }
        }
    }

    return {
        start: start,
        end: end
    };
}

MySQL SELECT x FROM a WHERE NOT IN ( SELECT x FROM b ) - Unexpected result

From documentation:

To comply with the SQL standard, IN returns NULL not only if the expression on the left hand side is NULL, but also if no match is found in the list and one of the expressions in the list is NULL.

This is exactly your case.

Both IN and NOT IN return NULL which is not an acceptable condition for WHERE clause.

Rewrite your query as follows:

SELECT  *
FROM    match m
WHERE   NOT EXISTS
        (
        SELECT  1
        FROM    email e
        WHERE   e.id = m.id
        )

OpenCV with Network Cameras

rtsp protocol did not work for me. mjpeg worked first try. I assume it is built into my camera (Dlink DCS 900).

Syntax found here: http://answers.opencv.org/question/133/how-do-i-access-an-ip-camera/

I did not need to compile OpenCV with ffmpg support.

Using setattr() in python

The Python docs say all that needs to be said, as far as I can see.

setattr(object, name, value)

This is the counterpart of getattr(). The arguments are an object, a string and an arbitrary value. The string may name an existing attribute or a new attribute. The function assigns the value to the attribute, provided the object allows it. For example, setattr(x, 'foobar', 123) is equivalent to x.foobar = 123.

If this isn't enough, explain what you don't understand.

Change a branch name in a Git repo

Assuming you're currently on the branch you want to rename:

git branch -m newname

This is documented in the manual for git-branch, which you can view using

man git-branch

or

git help branch

Specifically, the command is

git branch (-m | -M) [<oldbranch>] <newbranch>

where the parameters are:

   <oldbranch>
       The name of an existing branch to rename.

   <newbranch>
       The new name for an existing branch. The same restrictions as for <branchname> apply.

<oldbranch> is optional, if you want to rename the current branch.

Which concurrent Queue implementation should I use in Java?

Your question title mentions Blocking Queues. However, ConcurrentLinkedQueue is not a blocking queue.

The BlockingQueues are ArrayBlockingQueue, DelayQueue, LinkedBlockingDeque, LinkedBlockingQueue, PriorityBlockingQueue, and SynchronousQueue.

Some of these are clearly not fit for your purpose (DelayQueue, PriorityBlockingQueue, and SynchronousQueue). LinkedBlockingQueue and LinkedBlockingDeque are identical, except that the latter is a double-ended Queue (it implements the Deque interface).

Since ArrayBlockingQueue is only useful if you want to limit the number of elements, I'd stick to LinkedBlockingQueue.

How do you get a query string on Flask?

The full URL is available as request.url, and the query string is available as request.query_string.decode().

Here's an example:

from flask import request

@app.route('/adhoc_test/')
def adhoc_test():

    return request.query_string

To access an individual known param passed in the query string, you can use request.args.get('param'). This is the "right" way to do it, as far as I know.

ETA: Before you go further, you should ask yourself why you want the query string. I've never had to pull in the raw string - Flask has mechanisms for accessing it in an abstracted way. You should use those unless you have a compelling reason not to.

How to filter object array based on attributes?

I'm surprised no one has posted the one-line response:

const filteredHomes = json.homes.filter(x => x.price <= 1000 && x.sqft >= 500 && x.num_of_beds >=2 && x.num_of_baths >= 2.5);

...and just so you can read it easier:

const filteredHomes = json.homes.filter( x => 
  x.price <= 1000 && 
  x.sqft >= 500 && 
  x.num_of_beds >=2 && 
  x.num_of_baths >= 2.5
);

How to export a Vagrant virtual machine to transfer it

None of the above answers worked for me. I have been 2 days working out the way to migrate a Vagrant + VirtualBox Machine from a computer to another... It's possible!

First, you need to understand that the virtual machine is separated from your sync / shared folder. So when you pack your machine you're packing it without your files, but with the databases.

What you need to do:

1- Open the CMD of your computer 1 host machine (Command line. Open it as Adminitrator with the right button -> "Run as administrator") and go to your vagrant installed files. On my case: C:/VVV You will see your Vagrantfile an also these folders:

/config/
/database/
/log/
/provision/
/www/
Vagrantfile
...

The /www/ folder is where I have my Sync Folder with my development domains. You may have your sync folder in other place, just be sure to understand what you are doing. Also /config and /database are sync folders.

2- run this command: vagrant package --vagrantfile Vagrantfile

(This command does a package of your virtual machine using you Vagrantfile configuration.)

Here's what you can read on the Vagrant documentation about the command:

A common misconception is that the --vagrantfile option will package a Vagrantfile that is used when vagrant init is used with this box. This is not the case. Instead, a Vagrantfile is loaded and read as part of the Vagrant load process when the box is used. For more information, read about the Vagrantfile load order.

https://www.vagrantup.com/docs/cli/package.html

When finnished, you will have a package.box file.

3- Copy all these files (/config, /database, Vagrantfile, package.box, etc.) and paste them on your Computer 2 just where you want to install your virtual machine (on my case D:/VVV).

Now you have a copy of everything you need on your computer 2 host.

4- run this: vagrant box add package.box --name VVV

(The --name is used to name your virtual machine. On my case it's named VVV) (You can use --force if you already have a virtual machine with this name and want to overwrite it. (Use carefully !))

This will unpack your new vagrant Virtual machine.

5- When finnished, run: vagrant up

The machine will install and you should see it on the "Oracle virtual machine box manager". If you cannot see the virtual machine, try running the Oracle VM box as administrator (right click -> Run as administrator)

You now may have everything ok but remember to see if your hosts are as you expected:

c:/windows/system32/hosts

6- Maybe it's a good idea to copy your host file from your Computer 1 to your Computer 2. Or copy the lines you need. In my case these are the hosts I need:

192.168.50.4 test.dev
192.168.50.4 vvv.dev
...

Where the 192.168.50.4 is the IP of my Virtual machine and test.dev and vvv.dev are developing hosts.

I hope this can help you :) I'll be happy if you feedback your go.

Some particularities of my case that you may find:

When I ran vagrant up, there was a problem with mysql, it wasn't working. I had to run on the Virtual server (right click on the oracle virtual machine -> Show console): apt-get install mysql-server

After this, I ran again vagrant up and everything was working but without data on the databases. So I did a mysqldump all-tables from the Computer 1 and upload them to Computer 2.

OTHER NOTES: My virtual machine is not exactly on Computer 1 and Computer 2. For example, I made some time ago internal configuration to use NFS (to speed up the server sync folders) and I needed to run again this command on the Computer 2 host: vagrant plugin install vagrant-winnfsd

Example of a strong and weak entity types

First Strong/Weak Reference types are introduced in ARC. In Non ARC assign/retain are being used. A strong reference means that you want to "own" the object you are referencing with this property/variable. The compiler will take care that any object that you assign to this property will not be destroyed as long as you points to it with a strong reference. Only once you set the property to nil, the object get destroyed.

A weak reference means you signify that you don't want to have control over the object's lifetime or don't want to "own" object. The object you are referencing weakly only lives on because at least one other object holds a strong reference to it. Once that is no longer the case, the object gets destroyed and your weak property will automatically get set to nil. The most frequent use cases of weak references in iOS are for IBOutlets, Delegates etc.

For more info Refer : http://www.informit.com/articles/article.aspx?p=1856389&seqNum=5

How do I delete all messages from a single queue using the CLI?

I have successfully used ampq-purge from amqp-utils to do this:

git clone https://github.com/dougbarth/amqp-utils.git
cd amqp-utils
# extracted from Rakefile
echo "source 'https://rubygems.org'
gem 'amqp', '~> 0.7.1'
gem 'trollop', '~> 1.16.2'
gem 'facets', '~> 2.9'
gem 'clio', '~> 0.3.0'
gem 'json', '~> 1.5'
gem 'heredoc_unindent', '~> 1.1.2'
gem 'msgpack', '~> 0.4.5'" > Gemfile
bundle install --path=$PWD/gems
export RUBYLIB=.
export GEM_HOME=$PWD/gems/ruby/1.9.1

ruby bin/amqp-purge -v -V /vhost -u user -p queue
# paste password at prompt

C++ - how to find the length of an integer

Code for finding Length of int and decimal number:

#include<iostream>
    #include<cmath>
    using namespace std;
    int main()
    {
        int len,num;
        cin >> num;
        len = log10(num) + 1;
        cout << len << endl;
        return 0;
    }
    //sample input output
    /*45566
    5

    Process returned 0 (0x0)   execution time : 3.292 s
    Press any key to continue.
    */

Installing Bootstrap 3 on Rails App

For me, the simplest way to do this is

1) Download and unzip bootstrap into vendor

2) Add the bootstrap path to your config

config.assets.paths << Rails.root.join("vendor/bootstrap-3.3.6-dist")

3) Require them

in css *= require css/bootstrap

in js //= require js/bootstrap

Done!

This methods makes the fonts load without any other special configuration and doesn't require moving the bootstrap files out of their self-contained directory.

Getting the difference between two Dates (months/days/hours/minutes/seconds) in Swift

I added a "long" version to Leo Dabus's asnwer in case you want to have a string that says something like "2 weeks ago" instead of just "2w"...

extension Date {
    /// Returns the amount of years from another date
    func years(from date: Date) -> Int {
        return Calendar.current.dateComponents([.year], from: date, to: self).year ?? 0
    }
    /// Returns the amount of months from another date
    func months(from date: Date) -> Int {
        return Calendar.current.dateComponents([.month], from: date, to: self).month ?? 0
    }
    /// Returns the amount of weeks from another date
    func weeks(from date: Date) -> Int {
        return Calendar.current.dateComponents([.weekOfYear], from: date, to: self).weekOfYear ?? 0
    }
    /// Returns the amount of days from another date
    func days(from date: Date) -> Int {
        return Calendar.current.dateComponents([.day], from: date, to: self).day ?? 0
    }
    /// Returns the amount of hours from another date
    func hours(from date: Date) -> Int {
        return Calendar.current.dateComponents([.hour], from: date, to: self).hour ?? 0
    }
    /// Returns the amount of minutes from another date
    func minutes(from date: Date) -> Int {
        return Calendar.current.dateComponents([.minute], from: date, to: self).minute ?? 0
    }
    /// Returns the amount of seconds from another date
    func seconds(from date: Date) -> Int {
        return Calendar.current.dateComponents([.second], from: date, to: self).second ?? 0
    }
    /// Returns the a custom time interval description from another date
    func offset(from date: Date) -> String {
        if years(from: date)   > 0 { return "\(years(from: date))y"   }
        if months(from: date)  > 0 { return "\(months(from: date))M"  }
        if weeks(from: date)   > 0 { return "\(weeks(from: date))w"   }
        if days(from: date)    > 0 { return "\(days(from: date))d"    }
        if hours(from: date)   > 0 { return "\(hours(from: date))h"   }
        if minutes(from: date) > 0 { return "\(minutes(from: date))m" }
        if seconds(from: date) > 0 { return "\(seconds(from: date))s" }
        return ""
    }

    func offsetLong(from date: Date) -> String {
        if years(from: date)   > 0 { return years(from: date) > 1 ? "\(years(from: date)) years ago" : "\(years(from: date)) year ago" }
        if months(from: date)  > 0 { return months(from: date) > 1 ? "\(months(from: date)) months ago" : "\(months(from: date)) month ago" }
        if weeks(from: date)   > 0 { return weeks(from: date) > 1 ? "\(weeks(from: date)) weeks ago" : "\(weeks(from: date)) week ago"   }
        if days(from: date)    > 0 { return days(from: date) > 1 ? "\(days(from: date)) days ago" : "\(days(from: date)) day ago" }
        if hours(from: date)   > 0 { return hours(from: date) > 1 ? "\(hours(from: date)) hours ago" : "\(hours(from: date)) hour ago"   }
        if minutes(from: date) > 0 { return minutes(from: date) > 1 ? "\(minutes(from: date)) minutes ago" : "\(minutes(from: date)) minute ago" }
        if seconds(from: date) > 0 { return seconds(from: date) > 1 ? "\(seconds(from: date)) seconds ago" : "\(seconds(from: date)) second ago" }
        return ""
    }

}

Python pip install module is not found. How to link python to pip location?

For the sake of anyone also using visual studio from a windows environment:

I realized that I could see my module installed when i ran pip install

py pip install [moduleName] 
py pip list

However debugging in visual studio was getting "module not found". Oddly, i was successfully running import [moduleName] when i ran the interpreter in powershell.

Reason:

visual studio was using the wrong interpreter at: C:\Users\[username]\AppData\Local\Programs\Python\Python37\

What I REALLY wanted was visual studio to use the virtualenv that i setup for my project. To do this, right click Python Environments in "solution explorer", select Add Virtual Environment..., and then select the folder where you created your virtual environment. enter image description here Then, under project settings, under the General tab, select your virtual environment in the dropdown.

enter image description here

Now visual studio should be using the same interpreter and everything should play nice!

Regarding C++ Include another class

C++ (and C for that matter) split the "declaration" and the "implementation" of types, functions and classes. You should "declare" the classes you need in a header-file (.h or .hpp), and put the corresponding implementation in a .cpp-file. Then, when you wish to use (access) a class somewhere, you #include the corresponding headerfile.

Example

ClassOne.hpp:

class ClassOne
{
public:
  ClassOne(); // note, no function body        
  int method(); // no body here either
private:
  int member;
};

ClassOne.cpp:

#include "ClassOne.hpp"

// implementation of constructor
ClassOne::ClassOne()
 :member(0)
{}

// implementation of "method"
int ClassOne::method()
{
  return member++;
}

main.cpp:

#include "ClassOne.hpp" // Bring the ClassOne declaration into "view" of the compiler

int main(int argc, char* argv[])
{
  ClassOne c1;
  c1.method();

  return 0;
}

How to add 'libs' folder in Android Studio?

libs and Assets folder in Android Studio:

Create libs folder inside app folder and Asset folder inside main in the project directory by exploring project directory.

Now come back to Android Studio and switch the combo box from Android to Project. enjoy...

Node.js setting up environment specific configs to be used with everyauth

A very useful solution is use the config module.

after install the module:

$ npm install config

You could create a default.json configuration file. (you could use JSON or JS object using extension .json5 )

For example

$ vi config/default.json

{
  "name": "My App Name",
  "configPath": "/my/default/path",
  "port": 3000
}

This default configuration could be override by environment config file or a local config file for a local develop environment:

production.json could be:

{
  "configPath": "/my/production/path",
  "port": 8080
}

development.json could be:

{
  "configPath": "/my/development/path",
  "port": 8081
}

In your local PC you could have a local.json that override all environment, or you could have a specific local configuration as local-production.json or local-development.json.

The full list of load order.

Inside your App

In your app you only need to require config and the needed attribute.

var conf = require('config'); // it loads the right file
var login = require('./lib/everyauthLogin', {configPath: conf.get('configPath'));

Load the App

load the app using:

NODE_ENV=production node app.js

or setting the correct environment with forever or pm2

Forever:

NODE_ENV=production forever [flags] start app.js [app_flags]

PM2 (via shell):

export NODE_ENV=staging
pm2 start app.js

PM2 (via .json):

process.json

{
   "apps" : [{
    "name": "My App",
    "script": "worker.js",
    "env": {
      "NODE_ENV": "development",
    },
    "env_production" : {
       "NODE_ENV": "production"
    }
  }]
}

And then

$ pm2 start process.json --env production

This solution is very clean and it makes easy set different config files for Production/Staging/Development environment and for local setting too.

Initializing C dynamic arrays

You need to allocate a block of memory and use it as an array as:

int *arr = malloc (sizeof (int) * n); /* n is the length of the array */
int i;

for (i=0; i<n; i++)
{
  arr[i] = 0;
}

If you need to initialize the array with zeros you can also use the memset function from C standard library (declared in string.h).

memset (arr, 0, sizeof (int) * n);

Here 0 is the constant with which every locatoin of the array will be set. Note that the last argument is the number of bytes to be set the the constant. Because each location of the array stores an integer therefore we need to pass the total number of bytes as this parameter.

Also if you want to clear the array to zeros, then you may want to use calloc instead of malloc. calloc will return the memory block after setting the allocated byte locations to zero.

After you have finished, free the memory block free (arr).

EDIT1

Note that if you want to assign a particular integer in locations of an integer array using memset then it will be a problem. This is because memset will interpret the array as a byte array and assign the byte you have given, to every byte of the array. So if you want to store say 11243 in each location then it will not be possible.

EDIT2

Also note why every time setting an int array to 0 with memset may not work: Why does "memset(arr, -1, sizeof(arr)/sizeof(int))" not clear an integer array to -1? as pointed out by @Shafik Yaghmour

How can I remove the search bar and footer added by the jQuery DataTables plugin?

For DataTables >=1.10, use:

$('table').dataTable({searching: false, paging: false, info: false});

For DataTables <1.10, use:

$('table').dataTable({bFilter: false, bInfo: false});

or using pure CSS:

.dataTables_filter, .dataTables_info { display: none; }

Select DISTINCT individual columns in django?

The other answers are fine, but this is a little cleaner, in that it only gives the values like you would get from a DISTINCT query, without any cruft from Django.

>>> set(ProductOrder.objects.values_list('category', flat=True))
{u'category1', u'category2', u'category3', u'category4'}

or

>>> list(set(ProductOrder.objects.values_list('category', flat=True)))
[u'category1', u'category2', u'category3', u'category4']

And, it works without PostgreSQL.

This is less efficient than using a .distinct(), presuming that DISTINCT in your database is faster than a python set, but it's great for noodling around the shell.

How to pass text in a textbox to JavaScript function?

if I have understood correct the question :

_x000D_
_x000D_
<!DOCTYPE HTML>_x000D_
<HEAD>_x000D_
<TITLE>Passing values</TITLE>_x000D_
<style>_x000D_
</style>_x000D_
</HEAD>_x000D_
Give a number :<input type="number" id="num"><br>_x000D_
<button onclick="MyFunction(num.value)">Press button...</button>_x000D_
<script>_x000D_
function MyFunction(num) {_x000D_
   document.write("<h1>You gave "+num+"</h1>");_x000D_
}_x000D_
</script>_x000D_
</BODY>_x000D_
</HTML>
_x000D_
_x000D_
_x000D_

PHP array: count or sizeof?

sizeof() is just an alias of count() as mentioned here

http://php.net/manual/en/function.sizeof.php

How to Replace dot (.) in a string in Java

You need two backslashes before the dot, one to escape the slash so it gets through, and the other to escape the dot so it becomes literal. Forward slashes and asterisk are treated literal.

str=xpath.replaceAll("\\.", "/*/");          //replaces a literal . with /*/

http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#replaceAll(java.lang.String,%20java.lang.String)

Resize Cross Domain Iframe Height

There is no options in javascript to find the height of a cross domain iframe height but you can done something like this with the help of some server side programming. I used PHP for this example

<code>
    <?php
$output = file_get_contents('http://yourdomain.com');
?>
<div id='iframediv'>
    <?php echo $output; ?>
</div>

<iframe style='display:none' id='iframe' src="http://yourdomain.com" width="100%" marginwidth="0" height="100%" marginheight="0" align="top" scrolling="auto" frameborder="0" hspace="0" vspace="0"> </iframe>

<script>
if(window.attachEvent) {
    window.attachEvent('onload', iframeResizer);
} else {
    if(window.onload) {
        var curronload = window.onload;
        var newonload = function(evt) {
            curronload(evt);
            iframeResizer(evt);
        };
        window.onload = newonload;
    } else {
        window.onload = iframeResizer;
    }
}
   function iframeResizer(){
        var result = document.getElementById("iframediv").offsetHeight;

        document.getElementById("iframe").style.height = result;
        document.getElementById("iframediv").style.display = 'none';
        document.getElementById("iframe").style.display = 'inline';
    }
</script>
</code>

Best way to replace multiple characters in a string?

Simply chain the replace functions like this

strs = "abc&def#ghi"
print strs.replace('&', '\&').replace('#', '\#')
# abc\&def\#ghi

If the replacements are going to be more in number, you can do this in this generic way

strs, replacements = "abc&def#ghi", {"&": "\&", "#": "\#"}
print "".join([replacements.get(c, c) for c in strs])
# abc\&def\#ghi

Removing elements from an array in C

You don't really want to be reallocing memory every time you remove something. If you know the rough size of your deck then choose an appropriate size for your array and keep a pointer to the current end of the list. This is a stack.

If you don't know the size of your deck, and think it could get really big as well as keeps changing size, then you will have to do something a little more complex and implement a linked-list.

In C, you have two simple ways to declare an array.

  1. On the stack, as a static array

    int myArray[16]; // Static array of 16 integers
    
  2. On the heap, as a dynamically allocated array

    // Dynamically allocated array of 16 integers
    int* myArray = calloc(16, sizeof(int));
    

Standard C does not allow arrays of either of these types to be resized. You can either create a new array of a specific size, then copy the contents of the old array to the new one, or you can follow one of the suggestions above for a different abstract data type (ie: linked list, stack, queue, etc).

How do I specify different Layouts in the ASP.NET MVC 3 razor ViewStart file?

This method is the simplest way for beginners to control Layouts rendering in your ASP.NET MVC application. We can identify the controller and render the Layouts as par controller, to do this we can write our code in _ViewStart file in the root directory of the Views folder. Following is an example shows how it can be done.

@{
    var controller = HttpContext.Current.Request.RequestContext.RouteData.Values["Controller"].ToString();
    string cLayout = "";

    if (controller == "Webmaster")
        cLayout = "~/Views/Shared/_WebmasterLayout.cshtml";
    else
        cLayout = "~/Views/Shared/_Layout.cshtml";

    Layout = cLayout;
}

Read Complete Article here "How to Render different Layout in ASP.NET MVC"

How to use Git Revert

git revert makes a new commit

git revert simply creates a new commit that is the opposite of an existing commit.

It leaves the files in the same state as if the commit that has been reverted never existed. For example, consider the following simple example:

$ cd /tmp/example
$ git init
Initialized empty Git repository in /tmp/example/.git/
$ echo "Initial text" > README.md
$ git add README.md
$ git commit -m "initial commit"
[master (root-commit) 3f7522e] initial commit
 1 file changed, 1 insertion(+)
 create mode 100644 README.md
$ echo "bad update" > README.md 
$ git commit -am "bad update"
[master a1b9870] bad update
 1 file changed, 1 insertion(+), 1 deletion(-)

In this example the commit history has two commits and the last one is a mistake. Using git revert:

$ git revert HEAD
[master 1db4eeb] Revert "bad update"
 1 file changed, 1 insertion(+), 1 deletion(-)

There will be 3 commits in the log:

$ git log --oneline
1db4eeb Revert "bad update"
a1b9870 bad update
3f7522e initial commit

So there is a consistent history of what has happened, yet the files are as if the bad update never occured:

cat README.md 
Initial text

It doesn't matter where in the history the commit to be reverted is (in the above example, the last commit is reverted - any commit can be reverted).

Closing questions

do you have to do something else after?

A git revert is just another commit, so e.g. push to the remote so that other users can pull/fetch/merge the changes and you're done.

Do you have to commit the changes revert made or does revert directly commit to the repo?

git revert is a commit - there are no extra steps assuming reverting a single commit is what you wanted to do.

Obviously you'll need to push again and probably announce to the team.

Indeed - if the remote is in an unstable state - communicating to the rest of the team that they need to pull to get the fix (the reverting commit) would be the right thing to do :).

Get all mysql selected rows into an array

you can call mysql_fetch_array() for no_of_row time

jquery toggle slide from left to right and back

Use this...

$('#cat_icon').click(function () {
    $('#categories').toggle("slow");
    //$('#cat_icon').hide();
});
$('.panel_title').click(function () {
    $('#categories').toggle("slow");
    //$('#cat_icon').show();
});

See this Example

Greetings.

How to solve Object reference not set to an instance of an object.?

I think you just need;

List<string> list = new List<string>();
list.Add("hai");

There is a difference between

List<string> list; 

and

List<string> list = new List<string>();

When you didn't use new keyword in this case, your list didn't initialized. And when you try to add it hai, obviously you get an error.

How to display line numbers in 'less' (GNU)

You can set an enviroment variable to always have these options apply to all less'd file:

export LESS='-RS#3NM~g'

Dynamically load JS inside JS

Necromancing.

I use this to load dependant scripts;
it works with IE8+ without adding any dependency on another library like jQuery !

var cScriptLoader = (function ()
{
    function cScriptLoader(files)
    {
        var _this = this;
        this.log = function (t)
        {
            console.log("ScriptLoader: " + t);
        };
        this.withNoCache = function (filename)
        {
            if (filename.indexOf("?") === -1)
                filename += "?no_cache=" + new Date().getTime();
            else
                filename += "&no_cache=" + new Date().getTime();
            return filename;
        };
        this.loadStyle = function (filename)
        {
            // HTMLLinkElement
            var link = document.createElement("link");
            link.rel = "stylesheet";
            link.type = "text/css";
            link.href = _this.withNoCache(filename);
            _this.log('Loading style ' + filename);
            link.onload = function ()
            {
                _this.log('Loaded style "' + filename + '".');
            };
            link.onerror = function ()
            {
                _this.log('Error loading style "' + filename + '".');
            };
            _this.m_head.appendChild(link);
        };
        this.loadScript = function (i)
        {
            var script = document.createElement('script');
            script.type = 'text/javascript';
            script.src = _this.withNoCache(_this.m_js_files[i]);
            var loadNextScript = function ()
            {
                if (i + 1 < _this.m_js_files.length)
                {
                    _this.loadScript(i + 1);
                }
            };
            script.onload = function ()
            {
                _this.log('Loaded script "' + _this.m_js_files[i] + '".');
                loadNextScript();
            };
            script.onerror = function ()
            {
                _this.log('Error loading script "' + _this.m_js_files[i] + '".');
                loadNextScript();
            };
            _this.log('Loading script "' + _this.m_js_files[i] + '".');
            _this.m_head.appendChild(script);
        };
        this.loadFiles = function ()
        {
            // this.log(this.m_css_files);
            // this.log(this.m_js_files);
            for (var i = 0; i < _this.m_css_files.length; ++i)
                _this.loadStyle(_this.m_css_files[i]);
            _this.loadScript(0);
        };
        this.m_js_files = [];
        this.m_css_files = [];
        this.m_head = document.getElementsByTagName("head")[0];
        // this.m_head = document.head; // IE9+ only
        function endsWith(str, suffix)
        {
            if (str === null || suffix === null)
                return false;
            return str.indexOf(suffix, str.length - suffix.length) !== -1;
        }
        for (var i = 0; i < files.length; ++i)
        {
            if (endsWith(files[i], ".css"))
            {
                this.m_css_files.push(files[i]);
            }
            else if (endsWith(files[i], ".js"))
            {
                this.m_js_files.push(files[i]);
            }
            else
                this.log('Error unknown filetype "' + files[i] + '".');
        }
    }
    return cScriptLoader;
})();
var ScriptLoader = new cScriptLoader(["foo.css", "Scripts/Script4.js", "foobar.css", "Scripts/Script1.js", "Scripts/Script2.js", "Scripts/Script3.js"]);
ScriptLoader.loadFiles();

If you are interested in the typescript-version used to create this:

class cScriptLoader {
    private m_js_files: string[];
    private m_css_files: string[];
    private m_head:HTMLHeadElement;
    
    private log = (t:any) =>
    {
        console.log("ScriptLoader: " + t);
    }
    
    
    constructor(files: string[]) {
        this.m_js_files = [];
        this.m_css_files = [];
        this.m_head = document.getElementsByTagName("head")[0];
        // this.m_head = document.head; // IE9+ only
        
        
        function endsWith(str:string, suffix:string):boolean 
        {
            if(str === null || suffix === null)
                return false;
                
            return str.indexOf(suffix, str.length - suffix.length) !== -1;
        }
        
        
        for(let i:number = 0; i < files.length; ++i) 
        {
            if(endsWith(files[i], ".css"))
            {
                this.m_css_files.push(files[i]);
            }
            else if(endsWith(files[i], ".js"))
            {
                this.m_js_files.push(files[i]);
            }
            else
                this.log('Error unknown filetype "' + files[i] +'".');
        }
        
    }
    
    
    public withNoCache = (filename:string):string =>
    {
        if(filename.indexOf("?") === -1)
            filename += "?no_cache=" + new Date().getTime();
        else
            filename += "&no_cache=" + new Date().getTime();
            
        return filename;    
    }
    

    public loadStyle = (filename:string) =>
    {
        // HTMLLinkElement
        let link = document.createElement("link");
        link.rel = "stylesheet";
        link.type = "text/css";
        link.href = this.withNoCache(filename);
        
        this.log('Loading style ' + filename);
        link.onload = () =>
        {
            this.log('Loaded style "' + filename + '".');
            
        };
        
        link.onerror = () =>
        {
            this.log('Error loading style "' + filename + '".');
        };
        
        this.m_head.appendChild(link);
    }
    
    
    public loadScript = (i:number) => 
    {
        let script = document.createElement('script');
        script.type = 'text/javascript';
        script.src = this.withNoCache(this.m_js_files[i]);
        
        var loadNextScript = () => 
        {
            if (i + 1 < this.m_js_files.length)
            {
                this.loadScript(i + 1);
            }
        }
        
        script.onload = () =>
        {
            this.log('Loaded script "' + this.m_js_files[i] + '".');
            loadNextScript();
        };
        
        
        script.onerror = () =>
        {
            this.log('Error loading script "' + this.m_js_files[i] + '".');
            loadNextScript();
        };
        
        
        this.log('Loading script "' + this.m_js_files[i] + '".');
        this.m_head.appendChild(script);
    }
    
    public loadFiles = () => 
    {
        // this.log(this.m_css_files);
        // this.log(this.m_js_files);
        
        for(let i:number = 0; i < this.m_css_files.length; ++i)
            this.loadStyle(this.m_css_files[i])
        
        this.loadScript(0);
    }
    
}


var ScriptLoader = new cScriptLoader(["foo.css", "Scripts/Script4.js", "foobar.css", "Scripts/Script1.js", "Scripts/Script2.js", "Scripts/Script3.js"]);
ScriptLoader.loadFiles();

If it's to load a dynamic list of scripts, write the scripts into an attribute, such as data-main, e.g. <script src="scriptloader.js" data-main="file1.js,file2.js,file3.js,etc." ></script>
and do a element.getAttribute("data-main").split(',')

such as

var target = document.currentScript || (function() {
  var scripts = document.getElementsByTagName('script');
  // Note: this is for IE as IE doesn't support currentScript
  // this does not work if you have deferred loading with async
  // e.g. <script src="..." async="async" ></script>
  // https://web.archive.org/web/20180618155601/https://www.w3schools.com/TAgs/att_script_async.asp
  return scripts[scripts.length - 1];
})();

target.getAttribute("data-main").split(',')

to obtain the list.

How to test abstract class in Java with JUnit?

If you have no concrete implementations of the class and the methods aren't static whats the point of testing them? If you have a concrete class then you'll be testing those methods as part of the concrete class's public API.

I know what you are thinking "I don't want to test these methods over and over thats the reason I created the abstract class", but my counter argument to that is that the point of unit tests is to allow developers to make changes, run the tests, and analyze the results. Part of those changes could include overriding your abstract class's methods, both protected and public, which could result in fundamental behavioral changes. Depending on the nature of those changes it could affect how your application runs in unexpected, possibly negative ways. If you have a good unit testing suite problems arising from these types changes should be apparent at development time.

What is the difference between resource and endpoint?

Consider a server which has the information of users, missions and their reward points.

  1. Users and Reward Points are the resources
  2. An end point can relate to more than one resource
  3. Endpoints can be described using either a description or a full or partial URL

enter image description here

Source: API Endpoints vs Resources

How to iterate over a JSONObject?

The simpler approach is (just found on W3Schools):

let data = {.....}; // JSON Object
for(let d in data){
    console.log(d); // It gives you property name
    console.log(data[d]); // And this gives you its value
}

UPDATE

This approach works fine until you deal with the nested object so this approach will work.

const iterateJSON = (jsonObject, output = {}) => {
  for (let d in jsonObject) {
    if (typeof jsonObject[d] === "string") {
      output[d] = jsonObject[d];
    }
    if (typeof jsonObject[d] === "object") {
      output[d] = iterateJSON(jsonObject[d]);
    }
  }
  return output;
}

And use the method like this

let output = iterateJSON(your_json_object);

Creating custom function in React component

Another way:

export default class Archive extends React.Component { 

  saySomething = (something) => {
    console.log(something);
  }

  handleClick = (e) => {
    this.saySomething("element clicked");
  }

  componentDidMount() {
    this.saySomething("component did mount");
  }

  render() {
    return <button onClick={this.handleClick} value="Click me" />;
  }
}

In this format you don't need to use bind

creating triggers for After Insert, After Update and After Delete in SQL

(Update: overlooked a fault in the matter, I have corrected)

(Update2: I wrote from memory the code screwed up, repaired it)

(Update3: check on SQLFiddle)

create table Derived_Values
  (
    BusinessUnit nvarchar(100) not null
    ,Questions nvarchar(100) not null
    ,Answer nvarchar(100)
    )

go

ALTER TABLE Derived_Values ADD CONSTRAINT PK_Derived_Values
PRIMARY KEY CLUSTERED (BusinessUnit, Questions);

create table Derived_Values_Test
  (
    BusinessUnit nvarchar(150)
    ,Questions nvarchar(100)
    ,Answer nvarchar(100)
    )

go

CREATE TRIGGER trgAfterUpdate ON  [Derived_Values]
FOR UPDATE
AS  
begin
    declare @BusinessUnit nvarchar(50)
    set @BusinessUnit = 'Updated Record -- After Update Trigger.'

    insert into 
        [Derived_Values_Test]
        --(BusinessUnit,Questions, Answer) 
    SELECT 
        @BusinessUnit + i.BusinessUnit, i.Questions, i.Answer
    FROM 
        inserted i
        inner join deleted d on i.BusinessUnit = d.BusinessUnit
end

go

CREATE TRIGGER trgAfterDelete ON  [Derived_Values]
FOR UPDATE
AS  
begin
    declare @BusinessUnit nvarchar(50)
    set @BusinessUnit = 'Deleted Record -- After Delete Trigger.'

    insert into 
        [Derived_Values_Test]
        --(BusinessUnit,Questions, Answer) 
    SELECT 
        @BusinessUnit + d.BusinessUnit, d.Questions, d.Answer
    FROM 
        deleted d
end

go

insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU1', 'Q11', 'A11')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU1', 'Q12', 'A12')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU2', 'Q21', 'A21')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU2', 'Q22', 'A22')

UPDATE Derived_Values SET Answer='Updated Answers A11' from Derived_Values WHERE (BusinessUnit = 'BU1') AND (Questions = 'Q11');
UPDATE Derived_Values SET Answer='Updated Answers A12' from Derived_Values WHERE (BusinessUnit = 'BU1') AND (Questions = 'Q12');
UPDATE Derived_Values SET Answer='Updated Answers A21' from Derived_Values WHERE (BusinessUnit = 'BU2') AND (Questions = 'Q21');
UPDATE Derived_Values SET Answer='Updated Answers A22' from Derived_Values WHERE (BusinessUnit = 'BU2') AND (Questions = 'Q22');

delete Derived_Values;

and then:

SELECT * FROM Derived_Values;
go

select * from Derived_Values_Test;


Record Count: 0;

BUSINESSUNIT    QUESTIONS   ANSWER
Updated Record -- After Update Trigger.BU1  Q11 Updated Answers A11
Deleted Record -- After Delete Trigger.BU1  Q11 A11
Updated Record -- After Update Trigger.BU1  Q12 Updated Answers A12
Deleted Record -- After Delete Trigger.BU1  Q12 A12
Updated Record -- After Update Trigger.BU2  Q21 Updated Answers A21
Deleted Record -- After Delete Trigger.BU2  Q21 A21
Updated Record -- After Update Trigger.BU2  Q22 Updated Answers A22
Deleted Record -- After Delete Trigger.BU2  Q22 A22

(Update4: If you want to sync: SQLFiddle)

create table Derived_Values
  (
    BusinessUnit nvarchar(100) not null
    ,Questions nvarchar(100) not null
    ,Answer nvarchar(100)
    )

go

ALTER TABLE Derived_Values ADD CONSTRAINT PK_Derived_Values
PRIMARY KEY CLUSTERED (BusinessUnit, Questions);

create table Derived_Values_Test
  (
    BusinessUnit nvarchar(150) not null
    ,Questions nvarchar(100) not null
    ,Answer nvarchar(100)
    )

go

ALTER TABLE Derived_Values_Test ADD CONSTRAINT PK_Derived_Values_Test
PRIMARY KEY CLUSTERED (BusinessUnit, Questions);

CREATE TRIGGER trgAfterInsert ON  [Derived_Values]
FOR INSERT
AS  
begin
    insert
        [Derived_Values_Test]
        (BusinessUnit,Questions,Answer)
    SELECT 
        i.BusinessUnit, i.Questions, i.Answer
    FROM 
        inserted i
end

go


CREATE TRIGGER trgAfterUpdate ON  [Derived_Values]
FOR UPDATE
AS  
begin
    declare @BusinessUnit nvarchar(50)
    set @BusinessUnit = 'Updated Record -- After Update Trigger.'

    update
        [Derived_Values_Test]
    set
        --BusinessUnit = i.BusinessUnit
        --,Questions = i.Questions
        Answer = i.Answer
    from
        [Derived_Values]
        inner join inserted i 
    on
        [Derived_Values].BusinessUnit = i.BusinessUnit
        and
        [Derived_Values].Questions = i.Questions
end

go

CREATE TRIGGER trgAfterDelete ON  [Derived_Values]
FOR DELETE
AS  
begin
    delete 
        [Derived_Values_Test]
    from
        [Derived_Values_Test]
        inner join deleted d 
    on
        [Derived_Values_Test].BusinessUnit = d.BusinessUnit
        and
        [Derived_Values_Test].Questions = d.Questions
end

go

insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU1', 'Q11', 'A11')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU1', 'Q12', 'A12')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU2', 'Q21', 'A21')
insert Derived_Values (BusinessUnit,Questions, Answer) values ('BU2', 'Q22', 'A22')

UPDATE Derived_Values SET Answer='Updated Answers A11' from Derived_Values WHERE (BusinessUnit = 'BU1') AND (Questions = 'Q11');
UPDATE Derived_Values SET Answer='Updated Answers A12' from Derived_Values WHERE (BusinessUnit = 'BU1') AND (Questions = 'Q12');
UPDATE Derived_Values SET Answer='Updated Answers A21' from Derived_Values WHERE (BusinessUnit = 'BU2') AND (Questions = 'Q21');
UPDATE Derived_Values SET Answer='Updated Answers A22' from Derived_Values WHERE (BusinessUnit = 'BU2') AND (Questions = 'Q22');

--delete Derived_Values;

And then:

SELECT * FROM Derived_Values;
go

select * from Derived_Values_Test;


BUSINESSUNIT    QUESTIONS   ANSWER
BU1 Q11 Updated Answers A11
BU1 Q12 Updated Answers A12
BU2 Q21 Updated Answers A21
BU2 Q22 Updated Answers A22

BUSINESSUNIT    QUESTIONS   ANSWER
BU1 Q11 Updated Answers A11
BU1 Q12 Updated Answers A12
BU2 Q21 Updated Answers A21
BU2 Q22 Updated Answers A22

How can I tell which button was clicked in a PHP form submit?

In HTML:

<input type="submit" id="btnSubmit" name="btnSubmit" value="Save Changes" />
<input type="submit" id="btnDelete" name="btnDelete" value="Delete" />

In PHP:

if (isset($_POST["btnSubmit"])){
  // "Save Changes" clicked
} else if (isset($_POST["btnDelete"])){
  // "Delete" clicked
}

format statement in a string resource file

Inside file strings.xml define a String resource like this:

<string name="string_to_format">Amount: %1$f  for %2$d days%3$s</string>

Inside your code (assume it inherits from Context) simply do the following:

 String formattedString = getString(R.string.string_to_format, floatVar, decimalVar, stringVar);

(In comparison to the answer from LocalPCGuy or Giovanny Farto M. the String.format method is not needed.)

accessing a variable from another class

You could make the variables public fields:

  public int width;
  public int height;

  DrawFrame() {
    this.width = 400;
    this.height = 400;
  }

You could then access the variables like so:

DrawFrame frame = new DrawFrame();
int theWidth = frame.width;
int theHeight = frame.height;

A better solution, however, would be to make the variables private fields add two accessor methods to your class, keeping the data in the DrawFrame class encapsulated:

 private int width;
 private int height;

 DrawFrame() {
    this.width = 400;
    this.height = 400;
 }

  public int getWidth() {
     return this.width;
  }

  public int getHeight() {
     return this.height;
  }

Then you can get the width/height like so:

  DrawFrame frame = new DrawFrame();
  int theWidth = frame.getWidth();
  int theHeight = frame.getHeight();

I strongly suggest you use the latter method.

Android Preventing Double Click On A Button

I needed that woking with fragments and just put a flag to controll the clicks: I only want the first one, the others can't access to the listener

private boolean flag = true;

...

@Override
public void onClick(View view) {

    ...

    if (flag) {

        ...

        listener.onFragmentInteraction(Constants.MY_FRAGMENT, bundle);
        flag = false;
    }

    ...

}

Hope it will useful, and correct me if it is not correct

How do you get the logical xor of two variables in Python?

As Zach explained, you can use:

xor = bool(a) ^ bool(b)

Personally, I favor a slightly different dialect:

xor = bool(a) + bool(b) == 1

This dialect is inspired from a logical diagramming language I learned in school where "OR" was denoted by a box containing =1 (greater than or equal to 1) and "XOR" was denoted by a box containing =1.

This has the advantage of correctly implementing exclusive or on multiple operands.

  • "1 = a ^ b ^ c..." means the number of true operands is odd. This operator is "parity".
  • "1 = a + b + c..." means exactly one operand is true. This is "exclusive or", meaning "one to the exclusion of the others".

socket.shutdown vs socket.close

it's mentioned right in the Socket Programming HOWTO (py2/py3)

Disconnecting

Strictly speaking, you’re supposed to use shutdown on a socket before you close it. The shutdown is an advisory to the socket at the other end. Depending on the argument you pass it, it can mean “I’m not going to send anymore, but I’ll still listen”, or “I’m not listening, good riddance!”. Most socket libraries, however, are so used to programmers neglecting to use this piece of etiquette that normally a close is the same as shutdown(); close(). So in most situations, an explicit shutdown is not needed.

...

Integer division: How do you produce a double?

You might consider wrapping the operations. For example:

class Utils
{
    public static double divide(int num, int denom) {
        return ((double) num) / denom;
    }
}

This allows you to look up (just once) whether the cast does exactly what you want. This method could also be subject to tests, to ensure that it continues to do what you want. It also doesn't matter what trick you use to cause the division (you could use any of the answers here), as long as it results in the correct result. Anywhere you need to divide two integers, you can now just call Utils::divide and trust that it does the right thing.

How should I remove all the leading spaces from a string? - swift

To remove all spaces from the string:

let space_removed_string = (yourstring?.components(separatedBy: " ").joined(separator: ""))!

How to uninstall jupyter

If you don't want to use pip-autoremove (since it removes dependencies shared among other packages) and pip3 uninstall jupyter just removed some packages, then do the following:

Copy-Paste:

sudo may be needed as per your need.

python3 -m pip uninstall -y jupyter jupyter_core jupyter-client jupyter-console jupyterlab_pygments notebook qtconsole nbconvert nbformat

Note:

The above command will only uninstall jupyter specific packages. I have not added other packages to uninstall since they might be shared among other packages (eg: Jinja2 is used by Flask, ipython is a separate set of packages themselves, tornado again might be used by others).

In any case, all the dependencies are mentioned below(as of 21 Nov, 2020. jupyter==4.4.0 )

If you are sure you want to remove all the dependencies, then you can use Stan_MD's answer.

attrs
backcall
bleach
decorator
defusedxml
entrypoints
importlib-metadata
ipykernel
ipython
ipython-genutils
ipywidgets
jedi
Jinja2
jsonschema
jupyter
jupyter-client
jupyter-console
jupyter-core
jupyterlab-pygments
MarkupSafe
mistune
more-itertools
nbconvert
nbformat
notebook
pandocfilters
parso
pexpect
pickleshare
prometheus-client
prompt-toolkit
ptyprocess
Pygments
pyrsistent
python-dateutil
pyzmq
qtconsole
Send2Trash
six
terminado
testpath
tornado
traitlets
wcwidth
webencodings
widgetsnbextension
zipp

Executive Edit:

pip3 uninstall jupyter
pip3 uninstall jupyter_core
pip3 uninstall jupyter-client
pip3 uninstall jupyter-console
pip3 uninstall jupyterlab_pygments
pip3 uninstall notebook
pip3 uninstall qtconsole
pip3 uninstall nbconvert
pip3 uninstall nbformat

Explanation of each:

  1. Uninstall jupyter dist-packages:

    pip3 uninstall jupyter

  2. Uninstall jupyter_core dist-packages (It also uninstalls following binaries: jupyter, jupyter-migrate,jupyter-troubleshoot):

    pip3 uninstall jupyter_core

  3. Uninstall jupyter-client:

    pip3 uninstall jupyter-client

  4. Uninstall jupyter-console:

    pip3 uninstall jupyter-console

  5. Uninstall jupyter-notebook (It also uninstalls following binaries: jupyter-bundlerextension, jupyter-nbextension, jupyter-notebook, jupyter-serverextension):

    pip3 uninstall notebook

  6. Uninstall jupyter-qtconsole :

    pip3 uninstall qtconsole

  7. Uninstall jupyter-nbconvert:

    pip3 uninstall nbconvert

  8. Uninstall jupyter-trust:

    pip3 uninstall nbformat

Show div when radio button selected

$('input[name=test]').click(function () {
    if (this.id == "watch-me") {
        $("#show-me").show('slow');
    } else {
        $("#show-me").hide('slow');
    }
});

http://jsfiddle.net/2SsAk/2/

INSERT SELECT statement in Oracle 11G

You don't need the 'values' clause when using a 'select' as your source.

insert into table1 (col1, col2) 
select t1.col1, t2.col2 from oldtable1 t1, oldtable2 t2;

How to swap String characters in Java?

import java.io.*;
class swaping
{
     public static void main(String args[]) 
     {
         String name="premkumarg";
         int len=name.length();
         char[] c = name.toCharArray();
         for(int i=0;i<len-1;i=i+2)
         {
             char temp= c[i];
             c[i]=c[i+1];
             c[i+1]=temp;
         }

         System.out.println("Swapping string is: ");
         System.out.println(c);

    }
}

What are the default access modifiers in C#?

I would like to add some documentation link. Check out more detail here.

enter image description here

Convert A String (like testing123) To Binary In Java

       int no=44;
             String bNo=Integer.toString(no,2);//binary output 101100
             String oNo=Integer.toString(no,8);//Oct output 54
             String hNo=Integer.toString(no,16);//Hex output 2C

              String bNo1= Integer.toBinaryString(no);//binary output 101100
              String  oNo1=Integer.toOctalString(no);//Oct output 54
              String  hNo1=Integer.toHexString(no);//Hex output 2C

              String sBNo="101100";
              no=Integer.parseInt(sBNo,2);//binary to int output 44

              String sONo="54";
              no=Integer.parseInt(sONo,8);//oct to int  output 44

              String sHNo="2C";
              no=Integer.parseInt(sHNo,16);//hex to int output 44

__init__() got an unexpected keyword argument 'user'

Check your imports. There could be two classes with the same name. Either from your code or from a library you are using. Personally that was the issue.

string decode utf-8

the core functions are getBytes(String charset) and new String(byte[] data). you can use these functions to do UTF-8 decoding.

UTF-8 decoding actually is a string to string conversion, the intermediate buffer is a byte array. since the target is an UTF-8 string, so the only parameter for new String() is the byte array, which calling is equal to new String(bytes, "UTF-8")

Then the key is the parameter for input encoded string to get internal byte array, which you should know beforehand. If you don't, guess the most possible one, "ISO-8859-1" is a good guess for English user.

The decoding sentence should be

String decoded = new String(encoded.getBytes("ISO-8859-1"));

How can I remove space (margin) above HTML header?

I solved the space issue by adding a border and removing is by setting a negative margin. Do not know what the underlying problem is though.

header {
  border-top: 1px solid gold !important;
  margin-top: -1px !important;
}

java.util.Date format conversion yyyy-mm-dd to mm-dd-yyyy

Date is a container for the number of milliseconds since the Unix epoch ( 00:00:00 UTC on 1 January 1970).

It has no concept of format.

Java 8+

LocalDateTime ldt = LocalDateTime.now();
System.out.println(DateTimeFormatter.ofPattern("MM-dd-yyyy", Locale.ENGLISH).format(ldt));
System.out.println(DateTimeFormatter.ofPattern("yyyy-MM-dd", Locale.ENGLISH).format(ldt));
System.out.println(ldt);

Outputs...

05-11-2018
2018-05-11
2018-05-11T17:24:42.980

Java 7-

You should be making use of the ThreeTen Backport

Original Answer

For example...

Date myDate = new Date();
System.out.println(myDate);
System.out.println(new SimpleDateFormat("MM-dd-yyyy").format(myDate));
System.out.println(new SimpleDateFormat("yyyy-MM-dd").format(myDate));
System.out.println(myDate);

Outputs...

Wed Aug 28 16:20:39 EST 2013
08-28-2013
2013-08-28
Wed Aug 28 16:20:39 EST 2013

None of the formatting has changed the underlying Date value. This is the purpose of the DateFormatters

Updated with additional example

Just in case the first example didn't make sense...

This example uses two formatters to format the same date. I then use these same formatters to parse the String values back to Dates. The resulting parse does not alter the way Date reports it's value.

Date#toString is just a dump of it's contents. You can't change this, but you can format the Date object any way you like

try {
    Date myDate = new Date();
    System.out.println(myDate);

    SimpleDateFormat mdyFormat = new SimpleDateFormat("MM-dd-yyyy");
    SimpleDateFormat dmyFormat = new SimpleDateFormat("yyyy-MM-dd");

    // Format the date to Strings
    String mdy = mdyFormat.format(myDate);
    String dmy = dmyFormat.format(myDate);

    // Results...
    System.out.println(mdy);
    System.out.println(dmy);
    // Parse the Strings back to dates
    // Note, the formats don't "stick" with the Date value
    System.out.println(mdyFormat.parse(mdy));
    System.out.println(dmyFormat.parse(dmy));
} catch (ParseException exp) {
    exp.printStackTrace();
}

Which outputs...

Wed Aug 28 16:24:54 EST 2013
08-28-2013
2013-08-28
Wed Aug 28 00:00:00 EST 2013
Wed Aug 28 00:00:00 EST 2013

Also, be careful of the format patterns. Take a closer look at SimpleDateFormat to make sure you're not using the wrong patterns ;)

Timeout function if it takes too long to finish

I rewrote David's answer using the with statement, it allows you do do this:

with timeout(seconds=3):
    time.sleep(4)

Which will raise a TimeoutError.

The code is still using signal and thus UNIX only:

import signal

class timeout:
    def __init__(self, seconds=1, error_message='Timeout'):
        self.seconds = seconds
        self.error_message = error_message
    def handle_timeout(self, signum, frame):
        raise TimeoutError(self.error_message)
    def __enter__(self):
        signal.signal(signal.SIGALRM, self.handle_timeout)
        signal.alarm(self.seconds)
    def __exit__(self, type, value, traceback):
        signal.alarm(0)

Set content of HTML <span> with Javascript

The Maximally Standards Compliant way to do it is to create a text node containing the text you want and append it to the span (removing any currently extant text nodes).

The way I would actually do it is to use jQuery's .text().

Java, How to add values to Array List used as value in HashMap

String courseID = "Comp-101";
List<String> scores = new ArrayList<String> ();
scores.add("100");
scores.add("90");
scores.add("80");
scores.add("97");

Map<String, ArrayList<String>> myMap = new HashMap<String, ArrayList<String>>();
myMap.put(courseID, scores);

Hope this helps!

Add my custom http header to Spring RestTemplate request / extend RestTemplate

If the goal is to have a reusable RestTemplate which is in general useful for attaching the same header to a series of similar request a org.springframework.boot.web.client.RestTemplateCustomizer parameter can be used with a RestTemplateBuilder:

 String accessToken= "<the oauth 2 token>";
 RestTemplate restTemplate = new RestTemplateBuilder(rt-> rt.getInterceptors().add((request, body, execution) -> {
        request.getHeaders().add("Authorization", "Bearer "+accessToken);
        return execution.execute(request, body);
    })).build();

How to destroy an object?

You're looking for unset().

But take into account that you can't explicitly destroy an object.

It will stay there, however if you unset the object and your script pushes PHP to the memory limits the objects not needed will be garbage collected. I would go with unset() (as opposed to setting it to null) as it seems to have better performance (not tested but documented on one of the comments from the PHP official manual).

That said, do keep in mind that PHP always destroys the objects as soon as the page is served. So this should only be needed on really long loops and/or heavy intensive pages.

Cannot inline bytecode built with JVM target 1.8 into bytecode that is being built with JVM target 1.6

If non of the above answers don't work you can do this in kotlin dsl

android {
...

    tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile> {
        kotlinOptions {
            jvmTarget = "1.8"
        }
    }
}

Create a menu Bar in WPF?

<DockPanel>
    <Menu DockPanel.Dock="Top">
        <MenuItem Header="_File">
            <MenuItem Header="_Open"/>
            <MenuItem Header="_Close"/>
            <MenuItem Header="_Save"/>
        </MenuItem>
    </Menu>
    <StackPanel></StackPanel>
</DockPanel>

JavaScript onclick redirect

Just do

onclick="SubmitFrm"

The javascript: prefix is only required for link URLs.

Getting mouse position in c#

Cursor.Position will get the current screen poisition of the mouse (if you are in a Control, the MousePosition property will also get the same value).

To set the mouse position, you will have to use Cursor.Position and give it a new Point:

Cursor.Position = new Point(x, y);

You can do this in your Main method before creating your form.

Error: invalid operands of types ‘const char [35]’ and ‘const char [2]’ to binary ‘operator+’

In line 2, there's a std::string involved (name). There are operations defined for char[] + std::string, std::string + char[], etc. "Hello " + name gives a std::string, which is added to " you are ", giving another string, etc.

In line 3, you're saying

char[] + char[] + char[]

and you can't just add arrays to each other.

highlight the navigation menu for the current page

Please Look at the following:

Here is what's working:

1.) top menu buttons are visible and highlight correctly

2.) sub menu buttons are not visible until top menu is clicked

Here is what needs work:

1.) when sub menu is clicked, looking for new page to keep the selected sub menu open (i will highlight the selected sub menu button for further clarification on navigation)

Please see code here: http://jsbin.com/ePawaju/1/edit

or here: http://www.ceramictilepro.com/_6testingonly.php#

<head>
<script src="http://code.jquery.com/jquery-latest.js"></script>
</head>

Do I need to put this script in the head section? Where is the best place?

<div class="left">
<nav class="vmenu">
    <ul class="vnavmenu">
        <li data-ref="Top1"><a class="hiLite navBarButton2" href="#">Home</a>
        </li>
    </ul>
    <ul class="Top1 navBarTextSize">
        <li><a class="hiLite navBarButton2_sub" href="http://www.ceramictilepro.com/_5testingonly.php">sub1</a>
        </li>
        <li><a class="hiLite navBarButton2_sub" href="http://www.ceramictilepro.com/_5testingonly.php">sub2</a>
        </li>
        <li><a class="hiLite navBarButton2_sub" href="http://www.ceramictilepro.com/_5testingonly.php">sub3</a>
        </li>
        <li><a class="hiLite navBarButton2_sub" href="http://www.ceramictilepro.com/_5testingonly.php">sub4</a>
        </li>
    </ul>
    <ul class="vnavmenu">
        <li data-ref="Top2"><a class="hiLite navBarButton2" href="#">Repairs</a>
        </li>
    </ul>
    <ul class="Top2 navBarTextSize">
        <li><a class="hiLite navBarButton2_sub" href="http://www.ceramictilepro.com/_5testingonly.php">1sub1</a>
        </li>
        <li><a class="hiLite navBarButton2_sub" href="http://www.ceramictilepro.com/_5testingonly.php">2sub2</a>
        </li>
        <li><a class="hiLite navBarButton2_sub" href="http://www.ceramictilepro.com/_5testingonly.php">3sub3</a>
        </li>
        <li><a class="hiLite navBarButton2_sub" href="http://www.ceramictilepro.com/_5testingonly.php">4sub4</a>
        </li>
    </ul>
</nav>

JQuery is new to me, any help would greatly be appreciated :) var submenu;

$('.vnavmenu li').click(function () {
var elems = $('.vmenu ul:not(.vnavmenu)').length;
var $refClass = $('.' + $(this).attr('data-ref'));
var visible = $refClass.is(':visible');

$('.vmenu ul:not(.vnavmenu)').slideUp(100, function () {

    if (elems == 1) {
        if (!visible) $refClass.slideDown('fast');
    }

    elems--;
});

if (visible) $('#breadcrumbs-pc').animate({
    'margin-top': '0rem'
}, 100);
else $('#breadcrumbs-pc').animate({
    'margin-top': '5rem'
}, 100);
});

CSS background image to fit width, height should auto-scale in proportion

Background image is not Set Perfect then his css is problem create so his css file change to below code

_x000D_
_x000D_
html {  _x000D_
  background-image: url("example.png");  _x000D_
  background-repeat: no-repeat;  _x000D_
  background-position: 0% 0%;_x000D_
  background-size: 100% 100%;_x000D_
}
_x000D_
_x000D_
_x000D_

%; background-size: 100% 100%;"

How can I select random files from a directory in bash?

If you have more files in your folder, you can use the below piped command I found in unix stackexchange.

find /some/dir/ -type f -print0 | xargs -0 shuf -e -n 8 -z | xargs -0 cp -vt /target/dir/

Here I wanted to copy the files, but if you want to move files or do something else, just change the last command where I have used cp.

Make div 100% Width of Browser Window

If width:100% works in any cases, just use that, otherwise you can use vw in this case which is relative to 1% of the width of the viewport.

That means if you want to cover off the width, just use 100vw.

Look at the image I draw for you here:

enter image description here

Try the snippet I created for you as below:

_x000D_
_x000D_
.full-width {_x000D_
  width: 100vw;_x000D_
  height: 100px;_x000D_
  margin-bottom: 40px;_x000D_
  background-color: red;_x000D_
}_x000D_
_x000D_
.one-vw-width {_x000D_
  width: 1vw;_x000D_
  height: 100px;_x000D_
  background-color: red;_x000D_
}
_x000D_
<div class="full-width"></div>_x000D_
<div class="one-vw-width"></div>
_x000D_
_x000D_
_x000D_

Entity Framework 6 Code first Default value

Just Overload the default constructor of Model class and pass any relevant parameter which you may or may not use. By this you can easily supply default values for attributes. Below is an example.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Aim.Data.Domain
{
    [MetadataType(typeof(LoginModel))]
    public partial class Login
    {       
        public Login(bool status)
        {
            this.CreatedDate = DateTime.Now;
            this.ModifiedDate = DateTime.Now;
            this.Culture = "EN-US";
            this.IsDefaultPassword = status;
            this.IsActive = status;
            this.LoginLogs = new HashSet<LoginLog>();
            this.LoginLogHistories = new HashSet<LoginLogHistory>();
        }


    }

    public class LoginModel
    {

        [Key]
        [ScaffoldColumn(false)] 
        public int Id { get; set; }
        [Required]
        public string LoginCode { get; set; }
        [Required]
        public string Password { get; set; }
        public string LastPassword { get; set; }     
        public int UserGroupId { get; set; }
        public int FalseAttempt { get; set; }
        public bool IsLocked { get; set; }
        public int CreatedBy { get; set; }       
        public System.DateTime CreatedDate { get; set; }
        public Nullable<int> ModifiedBy { get; set; }      
        public Nullable<System.DateTime> ModifiedDate { get; set; }       
        public string Culture { get; set; }        
        public virtual ICollection<LoginLog> LoginLogs { get; set; }
        public virtual ICollection<LoginLogHistory> LoginLogHistories { get; set; }
    }

}