Programs & Examples On #Nsarraycontroller

on Mac OS X, NSArrayController is a bindings compatible class that manages a collection of objects

Android check internet connection

Here is a function which I use as a part of my Utils class:

public static boolean isNetworkConnected(Context context) {
    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    return (cm.getActiveNetworkInfo() != null) && cm.getActiveNetworkInfo().isConnectedOrConnecting();
}

Use it like: Utils.isNetworkConnected(MainActivity.this);

How do I remove diacritics (accents) from a string in .NET?

Try HelperSharp package.

There is a method RemoveAccents:

 public static string RemoveAccents(this string source)
 {
     //8 bit characters 
     byte[] b = Encoding.GetEncoding(1251).GetBytes(source);

     // 7 bit characters
     string t = Encoding.ASCII.GetString(b);
     Regex re = new Regex("[^a-zA-Z0-9]=-_/");
     string c = re.Replace(t, " ");
     return c;
 }

Vertically align text within a div

This is simply supposed to work:

#column-content {
        --------
    margin-top: auto;
    margin-bottom: auto;
}

I tried it on your demo.

How do I create a dynamic key to be added to a JavaScript object variable

Square brackets:

jsObj['key' + i] = 'example' + 1;

In JavaScript, all arrays are objects, but not all objects are arrays. The primary difference (and one that's pretty hard to mimic with straight JavaScript and plain objects) is that array instances maintain the length property so that it reflects one plus the numeric value of the property whose name is numeric and whose value, when converted to a number, is the largest of all such properties. That sounds really weird, but it just means that given an array instance, the properties with names like "0", "5", "207", and so on, are all treated specially in that their existence determines the value of length. And, on top of that, the value of length can be set to remove such properties. Setting the length of an array to 0 effectively removes all properties whose names look like whole numbers.

OK, so that's what makes an array special. All of that, however, has nothing at all to do with how the JavaScript [ ] operator works. That operator is an object property access mechanism which works on any object. It's important to note in that regard that numeric array property names are not special as far as simple property access goes. They're just strings that happen to look like numbers, but JavaScript object property names can be any sort of string you like.

Thus, the way the [ ] operator works in a for loop iterating through an array:

for (var i = 0; i < myArray.length; ++i) {
  var value = myArray[i]; // property access
  // ...
}

is really no different from the way [ ] works when accessing a property whose name is some computed string:

var value = jsObj["key" + i];

The [ ] operator there is doing precisely the same thing in both instances. The fact that in one case the object involved happens to be an array is unimportant, in other words.

When setting property values using [ ], the story is the same except for the special behavior around maintaining the length property. If you set a property with a numeric key on an array instance:

myArray[200] = 5;

then (assuming that "200" is the biggest numeric property name) the length property will be updated to 201 as a side-effect of the property assignment. If the same thing is done to a plain object, however:

myObj[200] = 5;

there's no such side-effect. The property called "200" of both the array and the object will be set to the value 5 in otherwise the exact same way.

One might think that because that length behavior is kind-of handy, you might as well make all objects instances of the Array constructor instead of plain objects. There's nothing directly wrong about that (though it can be confusing, especially for people familiar with some other languages, for some properties to be included in the length but not others). However, if you're working with JSON serialization (a fairly common thing), understand that array instances are serialized to JSON in a way that only involves the numerically-named properties. Other properties added to the array will never appear in the serialized JSON form. So for example:

var obj = [];
obj[0] = "hello world";
obj["something"] = 5000;

var objJSON = JSON.stringify(obj);

the value of "objJSON" will be a string containing just ["hello world"]; the "something" property will be lost.

ES2015:

If you're able to use ES6 JavaScript features, you can use Computed Property Names to handle this very easily:

var key = 'DYNAMIC_KEY',
    obj = {
        [key]: 'ES6!'
    };

console.log(obj);
// > { 'DYNAMIC_KEY': 'ES6!' }

Reducing video size with same format and reducing frame size

If you want to keep same screen size, you can consider using crf factor: https://trac.ffmpeg.org/wiki/Encode/H.264

Here is the command which works for me: (on mac you need to add -strict -2 to be able to use aac audio codec.

ffmpeg -i input.mp4 -c:v libx264 -crf 24 -b:v 1M -c:a aac output.mp4

How to store arrays in MySQL?

A sidenote to consider, you can store arrays in Postgres.

How do I break out of a loop in Perl?

For Perl one-liners with implicit loops (using -n or -p command line options), use last or last LINE to break out of the loop that iterates over input records. For example, these simple examples all print the first 2 lines of the input:

echo 1 2 3 4 | xargs -n1 | perl -ne 'last if $. == 3; print;'
echo 1 2 3 4 | xargs -n1 | perl -ne 'last LINE if $. == 3; print;'
echo 1 2 3 4 | xargs -n1 | perl -pe 'last if $. == 3;'
echo 1 2 3 4 | xargs -n1 | perl -pe 'last LINE if $. == 3;'

All print:

1
2

The perl one-liners use these command line flags:
-e : tells Perl to look for code in-line, instead of in a file.
-n : loop over the input one line at a time, assigning it to $_ by default.
-p : same as -n, also add print after each loop iteration over the input.

SEE ALSO:

last docs
last, next, redo, continue - an illustrated example
perlrun: command line switches docs


More examples of last in Perl one-liners:

Break one liner command line script after first match
Print the first N lines of a huge file

Calculate text width with JavaScript

The width and heigth of a text can be obtained with clientWidth and clientHeight

var element = document.getElementById ("mytext");

var width = element.clientWidth;
var height = element.clientHeight;

make sure that style position property is set to absolute

element.style.position = "absolute";

not required to be inside a div, can be inside a p or a span

Get current rowIndex of table in jQuery

Try this,

$('td').click(function(){
   var row_index = $(this).parent().index();
   var col_index = $(this).index();
});

If you need the index of table contain td then you can change it to

var row_index = $(this).parent('table').index(); 

How do I concatenate multiple C++ strings on one line?

Maybe you like my "Streamer" solution to really do it in one line:

#include <iostream>
#include <sstream>
using namespace std;

class Streamer // class for one line string generation
{
public:

    Streamer& clear() // clear content
    {
        ss.str(""); // set to empty string
        ss.clear(); // clear error flags
        return *this;
    }

    template <typename T>
    friend Streamer& operator<<(Streamer& streamer,T str); // add to streamer

    string str() // get current string
    { return ss.str();}

private:
    stringstream ss;
};

template <typename T>
Streamer& operator<<(Streamer& streamer,T str)
{ streamer.ss<<str;return streamer;}

Streamer streamer; // make this a global variable


class MyTestClass // just a test class
{
public:
    MyTestClass() : data(0.12345){}
    friend ostream& operator<<(ostream& os,const MyTestClass& myClass);
private:
    double data;
};

ostream& operator<<(ostream& os,const MyTestClass& myClass) // print test class
{ return os<<myClass.data;}


int main()
{
    int i=0;
    string s1=(streamer.clear()<<"foo"<<"bar"<<"test").str();                      // test strings
    string s2=(streamer.clear()<<"i:"<<i++<<" "<<i++<<" "<<i++<<" "<<0.666).str(); // test numbers
    string s3=(streamer.clear()<<"test class:"<<MyTestClass()).str();              // test with test class
    cout<<"s1: '"<<s1<<"'"<<endl;
    cout<<"s2: '"<<s2<<"'"<<endl;
    cout<<"s3: '"<<s3<<"'"<<endl;
}

How to use Global Variables in C#?

A useful feature for this is using static

As others have said, you have to create a class for your globals:

public static class Globals {
    public const float PI = 3.14;
}

But you can import it like this in order to no longer write the class name in front of its static properties:

using static Globals;
[...]
Console.WriteLine("Pi is " + PI);

Swift - Integer conversion to Hours/Minutes/Seconds

In macOS 10.10+ / iOS 8.0+ (NS)DateComponentsFormatter has been introduced to create a readable string.

It considers the user's locale und language.

let interval = 27005

let formatter = DateComponentsFormatter()
formatter.allowedUnits = [.hour, .minute, .second]
formatter.unitsStyle = .full

let formattedString = formatter.string(from: TimeInterval(interval))!
print(formattedString)

The available unit styles are positional, abbreviated, short, full, spellOut and brief.

For more information please read the documenation.

Styling HTML email for Gmail

Use inline styles for everything. This site will convert your classes to inline styles: http://premailer.dialect.ca/

What does [object Object] mean? (JavaScript)

Another option is to use JSON.stringify(obj)

For example:

exampleObj = {'a':1,'b':2,'c':3};
alert(JSON.stringify(exampleObj))

https://www.w3schools.com/js/js_json_stringify.asp

How do I implement onchange of <input type="text"> with jQuery?

You can use .change()

$('input[name=myInput]').change(function() { ... });

However, this event will only fire when the selector has lost focus, so you will need to click somewhere else to have this work.

If that's not quite right for you, you could use some of the other jQuery events like keyup, keydown or keypress - depending on the exact effect you want.

Programmatically Add CenterX/CenterY Constraints

The ObjectiveC equivalent is:

    myView.translatesAutoresizingMaskIntoConstraints = NO;

    [[myView.centerXAnchor constraintEqualToAnchor:self.view.centerXAnchor] setActive:YES];

    [[myView.centerYAnchor constraintEqualToAnchor:self.view.centerYAnchor] setActive:YES];

HttpServletRequest to complete URL

HttpUtil being deprecated, this is the correct method

StringBuffer url = req.getRequestURL();
String queryString = req.getQueryString();
if (queryString != null) {
    url.append('?');
    url.append(queryString);
}
String requestURL = url.toString();

Validate email with a regex in jQuery

This : /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/i is not working for below Gmail case

[email protected] [email protected]

Below Regex will cover all the E-mail Points: I have tried the all Possible Points and my Test case get also pass because of below regex

I found this Solution from this URL:

Regex Solution link

/(?:((?:[\w-]+(?:\.[\w-]+)*)@(?:(?:[\w-]+\.)*\w[\w-]{0,66})\.(?:[a-z]{2,6}(?:\.[a-z]{2})?));*)/g

Relative div height

When you set a percentage height on an element who's parent elements don't have heights set, the parent elements have a default

height: auto;

You are asking the browser to calculate a height from an undefined value. Since that would equal a null-value, the result is that the browser does nothing with the height of child elements.

Besides using a JavaScript solution you could use this deadly easy table method:

#parent3 {
    display: table;
    width: 100%;
}

#parent3 .between {
    display: table-row;
}

#parent3 .child {
    display: table-cell;
}

Preview on http://jsbin.com/IkEqAfi/1

  • Example 1: Not working
  • Example 2: Fix height
  • Example 3: Table method

But: Bare in mind, that the table method only works properly in all modern Browsers and the Internet Explorer 8 and higher. As Fallback you could use JavaScript.

How to delete a line from a text file in C#?

Why can't use this? First, create an array:

string[] lines = File.ReadAllLines(openFileDialog1.FileName);

Then look up the line you need to delete and replace it with "" :

lines[x].Replace(lines[x], "");

Done!

Creating a dictionary from a CSV file

You need a Python DictReader class. More help can be found from here

import csv

with open('file_name.csv', 'rt') as f:
    reader = csv.DictReader(f)
    for row in reader:
        print row

How do I make an Android EditView 'Done' button and hide the keyboard when clicked?

For the code:

editText.setImeOptions(EditorInfo.IME_ACTION_DONE);

SQL: how to use UNION and order by a specific select?

Using @Adrian tips, I found a solution:

I'm using GROUP BY and COUNT. I tried to use DISTINCT with ORDER BY but I'm getting error message: "not a SELECTed expression"

select id from 
(
    SELECT id FROM a -- returns 1,4,2,3
    UNION ALL -- changed to ALL
    SELECT id FROM b -- returns 2,1
)
GROUP BY id ORDER BY count(id);

Thanks Adrian and this blog.

How does MySQL CASE work?

CASE is more like a switch statement. It has two syntaxes you can use. The first lets you use any compare statements you want:

CASE 
    WHEN user_role = 'Manager' then 4
    WHEN user_name = 'Tom' then 27
    WHEN columnA <> columnB then 99
    ELSE -1 --unknown
END

The second style is for when you are only examining one value, and is a little more succinct:

CASE user_role
    WHEN 'Manager' then 4
    WHEN 'Part Time' then 7
    ELSE -1 --unknown
END

How can I select multiple columns from a subquery (in SQL Server) that should have one record (select top 1) for each record in the main query?

SELECT a.salesorderid, a.orderdate, s.orderdate, s.salesorderid
FROM A a
OUTER APPLY (SELECT top(1) *
             FROM B b WHERE a.salesorderid = b.salesorderid) as s
WHERE A.Date BETWEEN '2000-1-4' AND '2010-1-4'

How do I resolve "Run-time error '429': ActiveX component can't create object"?

This download fixed my VB6 EXE and Access 2016 (using ACEDAO.DLL) run-time error 429. Took me 2 long days to get it resolved because there are so many causes of 429.

http://www.microsoft.com/en-ca/download/details.aspx?id=13255

QUOTE from link: "This download will install a set of components that can be used to facilitate transfer of data between 2010 Microsoft Office System files and non-Microsoft Office applications"

Django Rest Framework -- no module named rest_framework

Maybe you install DRF is for python2, not for python3.

You can use python console to check your module:

import rest_framework

Actually you use pip to install module, it will install python2 module.

You should install the pip for python3:

sudo apt-get install python3-setuptools
sudo easy_install3 pip

So, you can install python3 module.

Using Javascript: How to create a 'Go Back' link that takes the user to a link if there's no history for the tab or window?

echo "<p><a href=\"javascript:history.go(-1)\" title=\"Return to previous page\">&laquo;Go back</a></p>";

Will go back one page.

echo "<p><a href=\"javascript:history.go(-2)\" title=\"Return to previous page\">&laquo;Go back</a></p>";

Will go back two pages.

How to use executables from a package installed locally in node_modules?

Use npm run[-script] <script name>

After using npm to install the bin package to your local ./node_modules directory, modify package.json to add <script name> like this:

$ npm install --save learnyounode
$ edit packages.json
>>> in packages.json
...
"scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "learnyounode": "learnyounode"
},
...
$ npm run learnyounode

It would be nice if npm install had a --add-script option or something or if npm run would work without adding to the scripts block.

dotnet ef not found in .NET Core 3

I had the same problem. I resolved, uninstalling all de the versions in my pc and then reinstall dotnet.

Position of a string within a string using Linux shell script?

With bash

a="The cat sat on the mat"
b=cat
strindex() { 
  x="${1%%$2*}"
  [[ "$x" = "$1" ]] && echo -1 || echo "${#x}"
}
strindex "$a" "$b"   # prints 4
strindex "$a" foo    # prints -1

Is it possible to run selenium (Firefox) web driver without a GUI?

Chrome now has a headless mode:

op = webdriver.ChromeOptions()
op.add_argument('--headless')
driver = webdriver.Chrome(options=op)

How to compare files from two different branches?

In order to compare two files in the git bash you need to use the command:

git diff <Branch name>..master -- Filename.extension   

This command will show the difference between the two files in the bash itself.

How to redirect in a servlet filter?

In Filter the response is of ServletResponse rather than HttpServletResponse. Hence do the cast to HttpServletResponse.

HttpServletResponse httpResponse = (HttpServletResponse) response;
httpResponse.sendRedirect("/login.jsp");

If using a context path:

httpResponse.sendRedirect(req.getContextPath() + "/login.jsp");

Also don't forget to call return; at the end.

java.lang.IllegalStateException: Cannot (forward | sendRedirect | create session) after response has been committed

A common misunderstanding among starters is that they think that the call of a forward(), sendRedirect(), or sendError() would magically exit and "jump" out of the method block, hereby ignoring the remnant of the code. For example:

protected void doXxx() {
    if (someCondition) {
        sendRedirect();
    }
    forward(); // This is STILL invoked when someCondition is true!
}

This is thus actually not true. They do certainly not behave differently than any other Java methods (expect of System#exit() of course). When the someCondition in above example is true and you're thus calling forward() after sendRedirect() or sendError() on the same request/response, then the chance is big that you will get the exception:

java.lang.IllegalStateException: Cannot forward after response has been committed

If the if statement calls a forward() and you're afterwards calling sendRedirect() or sendError(), then below exception will be thrown:

java.lang.IllegalStateException: Cannot call sendRedirect() after the response has been committed

To fix this, you need either to add a return; statement afterwards

protected void doXxx() {
    if (someCondition) {
        sendRedirect();
        return;
    }
    forward();
}

... or to introduce an else block.

protected void doXxx() {
    if (someCondition) {
        sendRedirect();
    } else {
        forward();
    }
}

To naildown the root cause in your code, just search for any line which calls a forward(), sendRedirect() or sendError() without exiting the method block or skipping the remnant of the code. This can be inside the same servlet before the particular code line, but also in any servlet or filter which was been called before the particular servlet.

In case of sendError(), if your sole purpose is to set the response status, use setStatus() instead.


Another probable cause is that the servlet writes to the response while a forward() will be called, or has been called in the very same method.

protected void doXxx() {
    out.write("some string");
    // ... 
    forward(); // Fail!
}

The response buffer size defaults in most server to 2KB, so if you write more than 2KB to it, then it will be committed and forward() will fail the same way:

java.lang.IllegalStateException: Cannot forward after response has been committed

Solution is obvious, just don't write to the response in the servlet. That's the responsibility of the JSP. You just set a request attribute like so request.setAttribute("data", "some string") and then print it in JSP like so ${data}. See also our Servlets wiki page to learn how to use Servlets the right way.


Another probable cause is that the servlet writes a file download to the response after which e.g. a forward() is called.

protected void doXxx() {
    out.write(bytes);
    // ... 
    forward(); // Fail!
}

This is technically not possible. You need to remove the forward() call. The enduser will stay on the currently opened page. If you actually intend to change the page after a file download, then you need to move the file download logic to page load of the target page.


Yet another probable cause is that the forward(), sendRedirect() or sendError() methods are invoked via Java code embedded in a JSP file in form of old fashioned way <% scriptlets %>, a practice which was officially discouraged since 2001. For example:

<!DOCTYPE html>
<html lang="en">
    <head>
        ... 
    </head>
    <body>
        ...

        <% sendRedirect(); %>
        
        ...
    </body>
</html>

The problem here is that JSP internally immediately writes template text (i.e. HTML code) via out.write("<!DOCTYPE html> ... etc ...") as soon as it's encountered. This is thus essentially the same problem as explained in previous section.

Solution is obvious, just don't write Java code in a JSP file. That's the responsibility of a normal Java class such as a Servlet or a Filter. See also our Servlets wiki page to learn how to use Servlets the right way.


See also:


Unrelated to your concrete problem, your JDBC code is leaking resources. Fix that as well. For hints, see also How often should Connection, Statement and ResultSet be closed in JDBC?

Python 3.4.0 with MySQL database

It seems that at the moment Ubuntu 15.10 has a but with python3 and pip3.

As elaborated in this article.

The problem makes pip3 install to python3.5 while python3 is actually running python3.4 :(

Until a proper solution will be available via the updates you can do one of the following:

run

python3 -m pip install pymysql

instead of

pip3 install pymysql

(or any other package)

Now

import pymysql

should work in python3 and in idle3.

Alternatively, if you explicitly need 3.5 you can use explicit python3.5 instead of python3. but idle3 will still point to 3.4...

What is the difference between user and kernel modes in operating systems?

I'm going to take a stab in the dark and guess you're talking about Windows. In a nutshell, kernel mode has full access to hardware, but user mode doesn't. For instance, many if not most device drivers are written in kernel mode because they need to control finer details of their hardware.

See also this wikibook.

Read and overwrite a file in Python

Try writing it in a new file..

f = open(filename, 'r+')
f2= open(filename2,'a+')
text = f.read()
text = re.sub('foobar', 'bar', text)
f.seek(0)
f.close()
f2.write(text)
fw.close()

Docker compose port mapping

It seems like the other answers here all misunderstood your question. If I understand correctly, you want to make requests to localhost:6379 (the default for redis) and have them be forwarded, automatically, to the same port on your redis container.

https://unix.stackexchange.com/a/101906/38639 helped me get to the right answer.

First, you'll need to install the nc command on your image. On CentOS, this package is called nmap-ncat, so in the example below, just replace this with the appropriate package if you are using a different OS as your base image.

Next, you'll need to tell it to run a certain command each time the container boots up. You can do this using CMD.

# Add this to your Dockerfile
RUN yum install -y --setopt=skip_missing_names_on_install=False nmap-ncat
COPY cmd.sh /usr/local/bin/cmd.sh
RUN chmod +x /usr/local/bin/cmd.sh
CMD ["/usr/local/bin/cmd.sh"]

Finally, we'll need to set up port-forwarding in cmd.sh. I found that nc, even with the -l and -k options, will occasionally terminate when a request is completed, so I'm using a while-loop to ensure that it's always running.

# cmd.sh
#! /usr/bin/env bash

while nc -l -p 6379 -k -c "nc redis 6379" || true; do true; done &

tail -f /dev/null # Or any other command that never exits

How do I profile memory usage in Python?

maybe it help:
<see additional>

pip install gprof2dot
sudo apt-get install graphviz

gprof2dot -f pstats profile_for_func1_001 | dot -Tpng -o profile.png

def profileit(name):
    """
    @profileit("profile_for_func1_001")
    """
    def inner(func):
        def wrapper(*args, **kwargs):
            prof = cProfile.Profile()
            retval = prof.runcall(func, *args, **kwargs)
            # Note use of name from outer scope
            prof.dump_stats(name)
            return retval
        return wrapper
    return inner

@profileit("profile_for_func1_001")
def func1(...)

What is the difference between String and StringBuffer in Java?

String is an immutable class. This means that once you instantiate an instance of a string like so:

String str1 = "hello";

The object in memory cannot be altered. Instead you will have to create a new instance, copy the old String and append whatever else as in this example:

String str1 = "hello";
str1 = str1 + " world!";

What is really happening hear is that we are NOT updating the existing str1 object... we are reallocating new memory all together, copying the "hello" data and appending " world!" to the end, then settings the str1 reference to point to this new memory. So it really looks more like this under the hood:

String str1 = "hello";
String str2 = str1 + " world!";
str1 = str2;

So it follows that this "copy + paste and move stuff around in memory" process can be very expensive if done repitively especially recursively.

When you are in that situation of having to do things over and over utilize StringBuilder. It is mutable and can append strings to the end of the current one because it's back by an [growing array] (not 100% if that is the actual data structure, could be a list).

"ssl module in Python is not available" when installing package with pip3

In my case with using Mac, I deleted /Applications/Python 3.7. because I already had Python3.7 by brew install python3 .

But it was a trigger of the message

pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.

What I did in my situation

  1. I downloaded macOS 64-bit installer again, and installed.
  2. Double click /Applications/Python3.6/Install Certificates.command and /Applications/Python3.6/Update Shell Profile.command.
  3. Reboot mac
  4. And I am not sure but possibly contributed to succeed is pip.conf. See pip install fails.

How to sort an STL vector?

std::sort(object.begin(), object.end(), pred());

where, pred() is a function object defining the order on objects of myclass. Alternatively, you can define myclass::operator<.

For example, you can pass a lambda:

std::sort(object.begin(), object.end(),
          [] (myclass const& a, myclass const& b) { return a.v < b.v; });

Or if you're stuck with C++03, the function object approach (v is the member on which you want to sort):

struct pred {
    bool operator()(myclass const & a, myclass const & b) const {
        return a.v < b.v;
    }
};

Importing packages in Java

In Java you can only import class Names, or static methods/fields.

To import class use

import full.package.name.of.SomeClass;

to import static methods/fields use

import static full.package.name.of.SomeClass.staticMethod;
import static full.package.name.of.SomeClass.staticField;

When and how should I use a ThreadLocal variable?

The documentation says it very well: "each thread that accesses [a thread-local variable] (via its get or set method) has its own, independently initialized copy of the variable".

You use one when each thread must have its own copy of something. By default, data is shared between threads.

Reading rows from a CSV file in Python

Reading it columnwise is harder?

Anyway this reads the line and stores the values in a list:

for line in open("csvfile.csv"):
    csv_row = line.split() #returns a list ["1","50","60"]

Modern solution:

# pip install pandas
import pandas as pd 
df = pd.read_table("csvfile.csv", sep=" ")

How do I count occurrence of duplicate items in array

Count duplicate element of an array in PHP without using in-built function

$arraychars=array("or","red","yellow","green","red","yellow","yellow");
$arrCount=array();
        for($i=0;$i<$arrlength-1;$i++)
        {
          $key=$arraychars[$i];
          if($arrCount[$key]>=1)
            {
              $arrCount[$key]++;
            } else{
              $arrCount[$key]=1;
        }
        echo $arraychars[$i]."<br>";
     }
        echo "<pre>";
        print_r($arrCount);

Trying to Validate URL Using JavaScript

I have found a great resource for comparing different solutions: https://mathiasbynens.be/demo/url-regex

According to that page, only solution from diegoperini passes all tests. Here is that regex:

_^(?:(?:https?|ftp)://)(?:\S+(?::\S*)?@)?(?:(?!10(?:\.\d{1,3}){3})(?!127(?:\.\d{1,3}){3})(?!169\.254(?:\.\d{1,3}){2})(?!192\.168(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)(?:\.(?:[a-z\x{00a1}-\x{ffff}0-9]+-?)*[a-z\x{00a1}-\x{ffff}0-9]+)*(?:\.(?:[a-z\x{00a1}-\x{ffff}]{2,})))(?::\d{2,5})?(?:/[^\s]*)?$_iuS

Read .doc file with python

I agree with Shivam's answer except for textract doesn't exist for windows. And, for some reason antiword also fails to read the '.doc' files and gives an error:

'filename.doc' is not a word document. # This happens when the file wasn't generated via MS Office. Eg: Web-pages may be stored in .doc format offline.

So, I've got the following workaround to extract the text:

from bs4 import BeautifulSoup as bs
soup = bs(open(filename).read())
[s.extract() for s in soup(['style', 'script'])]
tmpText = soup.get_text()
text = "".join("".join(tmpText.split('\t')).split('\n')).encode('utf-8').strip()
print text

This script will work with most kinds of files. Have fun!

How to check if one of the following items is in a list?

Simple.

_new_list = []
for item in a:
    if item in b:
        _new_list.append(item)
    else:
        pass

How to make unicode string with python3

What's new in Python 3.0 says:

All text is Unicode; however encoded Unicode is represented as binary data

If you want to ensure you are outputting utf-8, here's an example from this page on unicode in 3.0:

b'\x80abc'.decode("utf-8", "strict")

linux script to kill java process

If you just want to kill any/all java processes, then all you need is;

killall java

If, however, you want to kill the wskInterface process in particular, then you're most of the way there, you just need to strip out the process id;

PID=`ps -ef | grep wskInterface | awk '{ print $2 }'`
kill -9 $PID

Should do it, there is probably an easier way though...

Reset AutoIncrement in SQL Server after Delete

I want to add this answer because the DBCC CHECKIDENT-approach will product problems when you use schemas for tables. Use this to be sure:

DECLARE @Table AS NVARCHAR(500) = 'myschema.mytable';
DBCC CHECKIDENT (@Table, RESEED, 0);

If you want to check the success of the operation, use

SELECT IDENT_CURRENT(@Table);

which should output 0 in the example above.

Force IE10 to run in IE10 Compatibility View?

While you should fix your site so it works without Compatibility View, try putting the X-UA-Compatible meta tag as the very first thing after the opening <head>, before the title

How to append a newline to StringBuilder

For Kotlin,

StringBuilder().appendLine("your text");

Though this is a java question, this is also the first google result for Kotlin, might come in handy.

How do I revert all local changes in Git managed project to previous state?

Re-clone

GIT=$(git rev-parse --show-toplevel)
cd $GIT/..
rm -rf $GIT
git clone ...
  • ? Deletes local, non-pushed commits
  • ? Reverts changes you made to tracked files
  • ? Restores tracked files you deleted
  • ? Deletes files/dirs listed in .gitignore (like build files)
  • ? Deletes files/dirs that are not tracked and not in .gitignore
  • You won't forget this approach
  • Wastes bandwidth

Following are other commands I forget daily.

Clean and reset

git clean --force -d -x
git reset --hard
  • ? Deletes local, non-pushed commits
  • ? Reverts changes you made to tracked files
  • ? Restores tracked files you deleted
  • ? Deletes files/dirs listed in .gitignore (like build files)
  • ? Deletes files/dirs that are not tracked and not in .gitignore

Clean

git clean --force -d -x
  • ? Deletes local, non-pushed commits
  • ? Reverts changes you made to tracked files
  • ? Restores tracked files you deleted
  • ? Deletes files/dirs listed in .gitignore (like build files)
  • ? Deletes files/dirs that are not tracked and not in .gitignore

Reset

git reset --hard
  • ? Deletes local, non-pushed commits
  • ? Reverts changes you made to tracked files
  • ? Restores tracked files you deleted
  • ? Deletes files/dirs listed in .gitignore (like build files)
  • ? Deletes files/dirs that are not tracked and not in .gitignore

Notes

Test case for confirming all the above (use bash or sh):

mkdir project
cd project
git init
echo '*.built' > .gitignore
echo 'CODE' > a.sourceCode
mkdir b
echo 'CODE' > b/b.sourceCode
cp -r b c
git add .
git commit -m 'Initial checkin'
echo 'NEW FEATURE' >> a.sourceCode
cp a.sourceCode a.built
rm -rf c
echo 'CODE' > 'd.sourceCode'

See also

  • git revert to make new commits that undo prior commits
  • git checkout to go back in time to prior commits (may require running above commands first)
  • git stash same as git reset above, but you can undo it

Why use 'git rm' to remove a file instead of 'rm'?

Remove files from the index, or from the working tree and the index. git rm will not remove a file from just your working directory.

Here's how you might delete a file using rm -f and then remove it from your index with git rm

$ rm -f index.html
$ git status -s
 D index.html
$ git rm index.html
rm 'index.html'
$ git status -s
D  index.html

However you can do this all in one go with just git rm

$ git status -s
$ git rm index.html
rm 'index.html'
$ ls
lib vendor
$ git status -s
D  index.html

Python "string_escape" vs "unicode_escape"

According to my interpretation of the implementation of unicode-escape and the unicode repr in the CPython 2.6.5 source, yes; the only difference between repr(unicode_string) and unicode_string.encode('unicode-escape') is the inclusion of wrapping quotes and escaping whichever quote was used.

They are both driven by the same function, unicodeescape_string. This function takes a parameter whose sole function is to toggle the addition of the wrapping quotes and escaping of that quote.

500.21 Bad module "ManagedPipelineHandler" in its module list

I got this error on my ASP.Net 4.5 app on Windows Server 2012 R2.

Go to start menu -> "Turn windows features on or off". A wizard popped up for me.

Click Next to Server Roles

I had to check these to get this to work, located under Web Server IIS->Web Server-> Application Development (these are based on Jeremy Cook's answer above):

enter image description here

Then click next to Features and make sure the following is checked:

enter image description here

Then click next and Install. At this point, the error went away for me. Good luck!

"The certificate chain was issued by an authority that is not trusted" when connecting DB in VM Role from Azure website

I ran into this error trying to run the profiler, even though my connection had Trust server certificate checked and I added TrustServerCertificate=True in the Advanced Section. I changed to an instance of SSMS running as administrator and the profiler started with no problem. (I previously had found that when my connections even to local took a long time to connect, running as administrator helped).

Getting selected value of a combobox

The problem you have with the SelectedValue is not converting into integer. This is the main problem so usinge the following code snippet will help you:

int selectedValue;
bool parseOK = Int32.TryParse(cmb.SelectedValue.ToString(), out selectedValue);

Add MIME mapping in web.config for IIS Express

<system.webServer>
     <staticContent>
      <remove fileExtension=".woff"/>
      <mimeMap fileExtension=".woff" mimeType="application/font-woff" />
      <mimeMap fileExtension=".woff2" mimeType="font/woff2" />
    </staticContent>
  </system.webServer>

Bootstrap - floating navbar button right

Create a separate ul.nav for just that list item and float that ul right.

jsFiddle

Python update a key in dict if it doesn't exist

Since Python 3.9 you can use the merge operator | to merge two dictionaries. The dict on the right takes precedence:

new_dict = old_dict | { key: val }

For example:

new_dict = { 'a': 1, 'b': 2 } | { 'b': 42 }

print(new_dict} # {'a': 1, 'b': 42}

Note: this creates a new dictionary with the updated values.

sql how to cast a select query

Yes you can do.

Syntax for CAST:

CAST ( expression AS data_type [ ( length ) ] )

For example:

CAST(MyColumn AS Varchar(10))

CAST in SELECT Statement:

Select CAST(MyColumn AS Varchar(10)) AS MyColumn
FROM MyTable

See for more information CAST and CONVERT (Transact-SQL)

Are there such things as variables within an Excel formula?

There isn't a way to define a variable in the formula bar of Excel. As a workaround you could place the function in another cell (optionally, hiding the contents or placing it in a separate sheet). Otherwise you could create a VBA function.

np.mean() vs np.average() in Python NumPy?

In your invocation, the two functions are the same.

average can compute a weighted average though.

Doc links: mean and average

remove all variables except functions

You can use the following command to clear out ALL variables. Be careful because it you cannot get your variables back.

rm(list=ls(all=TRUE))

Access restriction: The type 'Application' is not API (restriction on required library rt.jar)

This happened to me as well, and the answers given here already were not satisfying, so I did my own research.

Background: Eclipse access restrictions

Eclipse has a mechanism called access restrictions to prevent you from accidentally using classes which Eclipse thinks are not part of the public API. Usually, Eclipse is right about that, in both senses: We usually do not want to use something which is not part of the public API. And Eclipse is usually right about what is and what isn't part of the public API.

Problem

Now, there can be situations, where you want to use public Non-API, like sun.misc (you shouldn't, unless you know what you're doing). And there can be situations, where Eclipse is not really right (that's what happened to me, I just wanted to use javax.smartcardio). In that case, we get this error in Eclipse.

Solution

The solution is to change the access restrictions.

  • Go to the properties of your Java project,
    • i.e. by selecting "Properties" from the context menu of the project in the "Package Explorer".
  • Go to "Java Build Path", tab "Libraries".
  • Expand the library entry
  • select
    • "Access rules",
    • "Edit..." and
    • "Add..." a "Resolution: Accessible" with a corresponding rule pattern. For me that was "javax/smartcardio/**", for you it might instead be "com/apple/eawt/**".

File count from a folder

System.IO.Directory myDir = GetMyDirectoryForTheExample();
int count = myDir.GetFiles().Length;

How can Bash execute a command in a different directory context?

(cd /path/to/your/special/place;/bin/your-special-command ARGS)

Java Enum Methods - return opposite direction enum

For those lured here by title: yes, you can define your own methods in your enum. If you are wondering how to invoke such non-static method, you do it same way as with any other non-static method - you invoke it on instance of type which defines or inherits that method. In case of enums such instances are simply ENUM_CONSTANTs.

So all you need is EnumType.ENUM_CONSTANT.methodName(arguments).


Now lets go back to problem from question. One of solutions could be

public enum Direction {

    NORTH, SOUTH, EAST, WEST;

    private Direction opposite;

    static {
        NORTH.opposite = SOUTH;
        SOUTH.opposite = NORTH;
        EAST.opposite = WEST;
        WEST.opposite = EAST;
    }

    public Direction getOppositeDirection() {
        return opposite;
    }

}

Now Direction.NORTH.getOppositeDirection() will return Direction.SOUTH.


Here is little more "hacky" way to illustrate @jedwards comment but it doesn't feel as flexible as first approach since adding more fields or changing their order will break our code.

public enum Direction {
    NORTH, EAST, SOUTH, WEST;

    // cached values to avoid recreating such array each time method is called
    private static final Direction[] VALUES = values();

    public Direction getOppositeDirection() {
        return VALUES[(ordinal() + 2) % 4]; 
    }
}

What does "select 1 from" do?

The construction is usually used in "existence" checks

if exists(select 1 from customer_table where customer = 'xxx')

or

if exists(select * from customer_table where customer = 'xxx')

Both constructions are equivalent. In the past people said the select * was better because the query governor would then use the best indexed column. This has been proven not true.

Remove Style on Element

Just use like this

 $("#sample_id").css("width", "");
 $("#sample_id").css("height", "");

Composer install error - requires ext_curl when it's actually enabled

try install php5-curl by using below snippet.

sudo apt-get install php5-curl

if it won't work try below code i m sure it will work fine.

sudo apt-get install php-curl

for me it worked... all the best :)

How to automatically start a service when running a docker container?

Simple! Add at the end of dockerfile:

ENTRYPOINT service mysql start && /bin/bash

Identify duplicate values in a list in Python

You can use list compression and set to reduce the complexity.

my_list = [3, 5, 2, 1, 4, 4, 1]
opt = [item for item in set(my_list) if my_list.count(item) > 1]

Javascript : Send JSON Object with Ajax?

If you`re not using jQuery then please make sure:

var json_upload = "json_name=" + JSON.stringify({name:"John Rambo", time:"2pm"});
var xmlhttp = new XMLHttpRequest();   // new HttpRequest instance 
xmlhttp.open("POST", "/file.php");
xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xmlhttp.send(json_upload);

And for the php receiving end:

 $_POST['json_name'] 

CKEditor automatically strips classes from div

Please refer to the official Advanced Content Filter guide and plugin integration tutorial.

You'll find much more than this about this powerful feature. Also see config.extraAllowedContent that seems suitable for your needs.

Refreshing Web Page By WebDriver When Waiting For Specific Condition

Another way to refresh the current page using selenium in Java.

//first: get the current URL in a String variable
String currentURL = driver.getCurrentUrl(); 
//second: call the current URL
driver.get(currentURL); 

Using this will refresh the current page like clicking the address bar of the browser and pressing enter.

Operator overloading ==, !=, Equals

As Selman22 said, you are overriding the default object.Equals method, which accepts an object obj and not a safe compile time type.

In order for that to happen, make your type implement IEquatable<Box>:

public class Box : IEquatable<Box>
{
    double height, length, breadth;

    public static bool operator ==(Box obj1, Box obj2)
    {
        if (ReferenceEquals(obj1, obj2))
        {
            return true;
        }
        if (ReferenceEquals(obj1, null))
        {
            return false;
        }
        if (ReferenceEquals(obj2, null))
        {
            return false;
        }

        return obj1.Equals(obj2);
    }

    public static bool operator !=(Box obj1, Box obj2)
    {
        return !(obj1 == obj2);
    }

    public bool Equals(Box other)
    {
        if (ReferenceEquals(other, null))
        {
            return false;
        }
        if (ReferenceEquals(this, other))
        {
            return true;
        }

        return height.Equals(other.height) 
               && length.Equals(other.length) 
               && breadth.Equals(other.breadth);
    }

    public override bool Equals(object obj)
    {
        return Equals(obj as Box);
    }

    public override int GetHashCode()
    {
        unchecked
        {
            int hashCode = height.GetHashCode();
            hashCode = (hashCode * 397) ^ length.GetHashCode();
            hashCode = (hashCode * 397) ^ breadth.GetHashCode();
            return hashCode;
        }
    }
}

Another thing to note is that you are making a floating point comparison using the equality operator and you might experience a loss of precision.

How to scp in Python?

It has been quite a while since this question was asked, and in the meantime, another library that can handle this has cropped up: You can use the copy function included in the Plumbum library:

import plumbum
r = plumbum.machines.SshMachine("example.net")
   # this will use your ssh config as `ssh` from shell
   # depending on your config, you might also need additional
   # params, eg: `user="username", keyfile=".ssh/some_key"`
fro = plumbum.local.path("some_file")
to = r.path("/path/to/destination/")
plumbum.path.utils.copy(fro, to)

Ruby: Calling class method from instance

If you have access to the delegate method you can do this:

[20] pry(main)> class Foo
[20] pry(main)*   def self.bar
[20] pry(main)*     "foo bar"
[20] pry(main)*   end  
[20] pry(main)*   delegate :bar, to: 'self.class'
[20] pry(main)* end  
=> [:bar]
[21] pry(main)> Foo.new.bar
=> "foo bar"
[22] pry(main)> Foo.bar
=> "foo bar"

Alternatively, and probably cleaner if you have more then a method or two you want to delegate to class & instance:

[1] pry(main)> class Foo
[1] pry(main)*   module AvailableToClassAndInstance
[1] pry(main)*     def bar
[1] pry(main)*       "foo bar"
[1] pry(main)*     end  
[1] pry(main)*   end  
[1] pry(main)*   include AvailableToClassAndInstance
[1] pry(main)*   extend AvailableToClassAndInstance
[1] pry(main)* end  
=> Foo
[2] pry(main)> Foo.new.bar
=> "foo bar"
[3] pry(main)> Foo.bar
=> "foo bar"

A word of caution:

Don't just randomly delegate everything that doesn't change state to class and instance because you'll start running into strange name clash issues. Do this sparingly and only after you checked nothing else is squashed.

How to create a Java cron job

You can use TimerTask for Cronjobs.

Main.java

public class Main{
   public static void main(String[] args){

     Timer t = new Timer();
     MyTask mTask = new MyTask();
     // This task is scheduled to run every 10 seconds

     t.scheduleAtFixedRate(mTask, 0, 10000);
   }

}

MyTask.java

class MyTask extends TimerTask{

   public MyTask(){
     //Some stuffs
   }

   @Override
   public void run() {
     System.out.println("Hi see you after 10 seconds");
   }

}

Alternative You can also use ScheduledExecutorService.

How to draw an empty plot?

You need a new plot window, and also a coordinate system, so you need plot.new() and plot.window(), then you can start to add graph elements:

plot.new( )
plot.window( xlim=c(-5,5), ylim=c(-5,5) )

points( rnorm(100), rnorm(100) )
axis( side=1 )

example plot

state machines tutorials

State machines can be very complex for a complex problem. They are also subject to unexpected bugs. They can turn into a nightmare if someone runs into a bug or needs to change the logic in the future. They are also difficult to follow and debug without the state diagram. Structured programming is much better (for example you would probably not use a state machine at mainline level). You can use structured programming even in interrupt context (which is where state machines are usually used). See this article "Macros to simulate multi-tasking/blocking code at interrupt level" found at codeproject.com.

T-SQL: Export to new Excel file

This is by far the best post for exporting to excel from SQL:

http://www.sqlteam.com/forums/topic.asp?TOPIC_ID=49926

To quote from user madhivanan,

Apart from using DTS and Export wizard, we can also use this query to export data from SQL Server2000 to Excel

Create an Excel file named testing having the headers same as that of table columns and use these queries

1 Export data to existing EXCEL file from SQL Server table

insert into OPENROWSET('Microsoft.Jet.OLEDB.4.0', 
    'Excel 8.0;Database=D:\testing.xls;', 
    'SELECT * FROM [SheetName$]') select * from SQLServerTable

2 Export data from Excel to new SQL Server table

select * 
into SQLServerTable FROM OPENROWSET('Microsoft.Jet.OLEDB.4.0', 
    'Excel 8.0;Database=D:\testing.xls;HDR=YES', 
    'SELECT * FROM [Sheet1$]')

3 Export data from Excel to existing SQL Server table (edited)

Insert into SQLServerTable Select * FROM OPENROWSET('Microsoft.Jet.OLEDB.4.0', 
    'Excel 8.0;Database=D:\testing.xls;HDR=YES', 
    'SELECT * FROM [SheetName$]')

4 If you dont want to create an EXCEL file in advance and want to export data to it, use

EXEC sp_makewebtask 
    @outputfile = 'd:\testing.xls', 
    @query = 'Select * from Database_name..SQLServerTable', 
    @colheaders =1, 
    @FixedFont=0,@lastupdated=0,@resultstitle='Testing details'

(Now you can find the file with data in tabular format)

5 To export data to new EXCEL file with heading(column names), create the following procedure

create procedure proc_generate_excel_with_columns
(
    @db_name    varchar(100),
    @table_name varchar(100),   
    @file_name  varchar(100)
)
as

--Generate column names as a recordset
declare @columns varchar(8000), @sql varchar(8000), @data_file varchar(100)
select 
    @columns=coalesce(@columns+',','')+column_name+' as '+column_name 
from 
    information_schema.columns
where 
    table_name=@table_name
select @columns=''''''+replace(replace(@columns,' as ',''''' as '),',',',''''')

--Create a dummy file to have actual data
select @data_file=substring(@file_name,1,len(@file_name)-charindex('\',reverse(@file_name)))+'\data_file.xls'

--Generate column names in the passed EXCEL file
set @sql='exec master..xp_cmdshell ''bcp " select * from (select '+@columns+') as t" queryout "'+@file_name+'" -c'''
exec(@sql)

--Generate data in the dummy file
set @sql='exec master..xp_cmdshell ''bcp "select * from '+@db_name+'..'+@table_name+'" queryout "'+@data_file+'" -c'''
exec(@sql)

--Copy dummy file to passed EXCEL file
set @sql= 'exec master..xp_cmdshell ''type '+@data_file+' >> "'+@file_name+'"'''
exec(@sql)

--Delete dummy file 
set @sql= 'exec master..xp_cmdshell ''del '+@data_file+''''
exec(@sql)

After creating the procedure, execute it by supplying database name, table name and file path:

EXEC proc_generate_excel_with_columns 'your dbname', 'your table name','your file path'

Its a whomping 29 pages but that is because others show various other ways as well as people asking questions just like this one on how to do it.

Follow that thread entirely and look at the various questions people have asked and how they are solved. I picked up quite a bit of knowledge just skimming it and have used portions of it to get expected results.

To update single cells

A member also there Peter Larson posts the following: I think one thing is missing here. It is great to be able to Export and Import to Excel files, but how about updating single cells? Or a range of cells?

This is the principle of how you do manage that

update OPENROWSET('Microsoft.Jet.OLEDB.4.0', 
'Excel 8.0;Database=c:\test.xls;hdr=no', 
'SELECT * FROM [Sheet1$b7:b7]') set f1 = -99

You can also add formulas to Excel using this:

update OPENROWSET('Microsoft.Jet.OLEDB.4.0', 
'Excel 8.0;Database=c:\test.xls;hdr=no', 
'SELECT * FROM [Sheet1$b7:b7]') set f1 = '=a7+c7'

Exporting with column names using T-SQL

Member Mladen Prajdic also has a blog entry on how to do this here

References: www.sqlteam.com (btw this is an excellent blog / forum for anyone looking to get more out of SQL Server). For error referencing I used this

Errors that may occur

If you get the following error:

OLE DB provider 'Microsoft.Jet.OLEDB.4.0' cannot be used for distributed queries

Then run this:

sp_configure 'show advanced options', 1;
GO
RECONFIGURE;
GO
sp_configure 'Ad Hoc Distributed Queries', 1;
GO
RECONFIGURE;
GO

Git push hangs when pushing to Github?

I had the same problem with absolutely same symptoms… I was about to rebuild my whole system in my despair)).

I even was so naive to try git config --global core.askpass "git-gui--askpass" as some people suggest here, but it didn't work… git push was still freeze…

But then I figured out that there was an error with my SSH agent. So I've restarted ssh-agent and… PROFIT

Conclusion: Always check your SSH Agent and SSHD server when you have troubles with ssh connection… I'm pretty sure that was your problem (And that's why it worked after reinstallation of your system)

CMD: How do I recursively remove the "Hidden"-Attribute of files and directories

You can't remove hidden without also removing system.

You want:

cd mydir
attrib -H -S /D /S

That will remove the hidden and system attributes from all the files/folders inside of your current directory.

Simple 3x3 matrix inverse code (C++)

#include <iostream>
using namespace std;

int main()
{
    double A11, A12, A13;
    double A21, A22, A23;
    double A31, A32, A33;

    double B11, B12, B13;
    double B21, B22, B23;
    double B31, B32, B33;

    cout << "Enter all number from left to right, from top to bottom, and press enter after every number: ";
    cin  >> A11;
    cin  >> A12;
    cin  >> A13;
    cin  >> A21;
    cin  >> A22;
    cin  >> A23;
    cin  >> A31;
    cin  >> A32;
    cin  >> A33;

    B11 = 1 / ((A22 * A33) - (A23 * A32));
    B12 = 1 / ((A13 * A32) - (A12 * A33));
    B13 = 1 / ((A12 * A23) - (A13 * A22));
    B21 = 1 / ((A23 * A31) - (A21 * A33));
    B22 = 1 / ((A11 * A33) - (A13 * A31));
    B23 = 1 / ((A13 * A21) - (A11 * A23));
    B31 = 1 / ((A21 * A32) - (A22 * A31));
    B32 = 1 / ((A12 * A31) - (A11 * A32));
    B33 = 1 / ((A11 * A22) - (A12 * A21));

    cout << B11 << "\t" << B12 << "\t" << B13 << endl;
    cout << B21 << "\t" << B22 << "\t" << B23 << endl;
    cout << B31 << "\t" << B32 << "\t" << B33 << endl;

    return 0;
}

How to close TCP and UDP ports via windows command line

Use TCPView: http://technet.microsoft.com/en-us/sysinternals/bb897437.aspx
or CurrPorts: https://www.nirsoft.net/utils/cports.html

Alternatively, if you don't want to use EXTERNAL SOFTWARE (these tools don't require an installation by the way), you can simply FIRST run the netstat command (preferably netstat -b ) & then setup Local Security Policy to block the IP address of the user's machine in question, that's what I have been doing with unwanted or even unknown connections - that allows you doing everything WITHOUT ANY EXTERNAL SOFTWARE (everything comes with Windows)...

How to convert a factor to integer\numeric without loss of information?

The most easiest way would be to use unfactor function from package varhandle which can accept a factor vector or even a dataframe:

unfactor(your_factor_variable)

This example can be a quick start:

x <- rep(c("a", "b", "c"), 20)
y <- rep(c(1, 1, 0), 20)

class(x)  # -> "character"
class(y)  # -> "numeric"

x <- factor(x)
y <- factor(y)

class(x)  # -> "factor"
class(y)  # -> "factor"

library(varhandle)
x <- unfactor(x)
y <- unfactor(y)

class(x)  # -> "character"
class(y)  # -> "numeric"

You can also use it on a dataframe. For example the iris dataset:

sapply(iris, class)
Sepal.Length  Sepal.Width Petal.Length  Petal.Width      Species
   "numeric"    "numeric"    "numeric"    "numeric"     "factor"
# load the package
library("varhandle")
# pass the iris to unfactor
tmp_iris <- unfactor(iris)
# check the classes of the columns
sapply(tmp_iris, class)
Sepal.Length  Sepal.Width Petal.Length  Petal.Width      Species
   "numeric"    "numeric"    "numeric"    "numeric"  "character"
# check if the last column is correctly converted
tmp_iris$Species
  [1] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"    
  [6] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"    
 [11] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"    
 [16] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"    
 [21] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"    
 [26] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"    
 [31] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"
 [36] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"
 [41] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"
 [46] "setosa"     "setosa"     "setosa"     "setosa"     "setosa"
 [51] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [56] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [61] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [66] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [71] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [76] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [81] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [86] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [91] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
 [96] "versicolor" "versicolor" "versicolor" "versicolor" "versicolor"
[101] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[106] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[111] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[116] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[121] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[126] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[131] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[136] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[141] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"
[146] "virginica"  "virginica"  "virginica"  "virginica"  "virginica"

Difference between "Complete binary tree", "strict binary tree","full binary Tree"?

Disclaimer- The main source of some definitions are wikipedia, any suggestion to improve my answer is welcome.

Although this post has an accepted answer and is a good one I was still in confusion and would like to add some more clarification regarding the difference between these terms.

(1)FULL BINARY TREE- A full binary tree is a binary tree in which every node other than the leaves has two children.This is also called strictly binary tree.

enter image description here enter image description here

The above two are the examples of full or strictly binary tree.

(2)COMPLETE BINARY TREE- Now, the definition of complete binary tree is quite ambiguous, it states :- A complete binary tree is a binary tree in which every level, except possibly the last, is completely filled, and all nodes are as far left as possible. It can have between 1 and 2h nodes, as far left as possible, at the last level h

Notice the lines in italic.

The ambiguity lies in the lines in italics , "except possibly the last" which means that the last level may also be completely filled , i.e this exception need not always be satisfied. If the exception doesn't hold then it is exactly like the second image I posted, which can also be called as perfect binary tree. So, a perfect binary tree is also full and complete but not vice-versa which will be clear by one more definition I need to state:

ALMOST COMPLETE BINARY TREE- When the exception in the definition of complete binary tree holds then it is called almost complete binary tree or nearly complete binary tree . It is just a type of complete binary tree itself , but a separate definition is necessary to make it more unambiguous.

So an almost complete binary tree will look like this, you can see in the image the nodes are as far left as possible so it is more like a subset of complete binary tree , to say more rigorously every almost complete binary tree is a complete binary tree but not vice versa . :

enter image description here

Escape a string for a sed replace pattern

The only three literal characters which are treated specially in the replace clause are / (to close the clause), \ (to escape characters, backreference, &c.), and & (to include the match in the replacement). Therefore, all you need to do is escape those three characters:

sed "s/KEYWORD/$(echo $REPLACE | sed -e 's/\\/\\\\/g; s/\//\\\//g; s/&/\\\&/g')/g"

Example:

$ export REPLACE="'\"|\\/><&!"
$ echo fooKEYWORDbar | sed "s/KEYWORD/$(echo $REPLACE | sed -e 's/\\/\\\\/g; s/\//\\\//g; s/&/\\\&/g')/g"
foo'"|\/><&!bar

Margin between items in recycler view Android

Use CompatPadding in CardView Item

How can I find last row that contains data in a specific column?

You should use the .End(xlup) but instead of using 65536 you might want to use:

sheetvar.Rows.Count

That way it works for Excel 2007 which I believe has more than 65536 rows

Search of table names

I'm using this and works fine

SELECT * FROM INFORMATION_SCHEMA.TABLES 
WHERE TABLE_NAME LIKE '%%'

Node update a specific package

Most of the time you can just npm update (or yarn upgrade) a module to get the latest non breaking changes (respecting the semver specified in your package.json) (<-- read that last part again).

npm update browser-sync
-------
yarn upgrade browser-sync
  • Use npm|yarn outdated to see which modules have newer versions
  • Use npm update|yarn upgrade (without a package name) to update all modules
  • Include --save-dev|--dev if you want to save the newer version numbers to your package.json. (NOTE: as of npm v5.0 this is only necessary for devDependencies).

Major version upgrades:

In your case, it looks like you want the next major version (v2.x.x), which is likely to have breaking changes and you will need to update your app to accommodate those changes. You can install/save the latest 2.x.x by doing:

npm install browser-sync@2 --save-dev
-------
yarn add browser-sync@2 --dev

...or the latest 2.1.x by doing:

npm install [email protected] --save-dev
-------
yarn add [email protected] --dev

...or the latest and greatest by doing:

npm install browser-sync@latest --save-dev
-------
yarn add browser-sync@latest --dev

Note: the last one is no different than doing this:

npm uninstall browser-sync --save-dev
npm install browser-sync --save-dev
-------
yarn remove browser-sync --dev
yarn add browser-sync --dev

The --save-dev part is important. This will uninstall it, remove the value from your package.json, and then reinstall the latest version and save the new value to your package.json.

How to use JavaScript with Selenium WebDriver Java

Based on your previous questions, I suppose you want to run JavaScript snippets from Java's WebDriver. Please correct me if I'm wrong.

The WebDriverJs is actually "just" another WebDriver language binding (you can write your tests in Java, C#, Ruby, Python, JS and possibly even more languages as of now). This one, particularly, is JavaScript, and allows you therefore to write tests in JavaScript.

If you want to run JavaScript code in Java WebDriver, do this instead:

WebDriver driver = new AnyDriverYouWant();
if (driver instanceof JavascriptExecutor) {
    ((JavascriptExecutor)driver).executeScript("yourScript();");
} else {
    throw new IllegalStateException("This driver does not support JavaScript!");
}

I like to do this, also:

WebDriver driver = new AnyDriverYouWant();
JavascriptExecutor js;
if (driver instanceof JavascriptExecutor) {
    js = (JavascriptExecutor)driver;
} // else throw...

// later on...
js.executeScript("return document.getElementById('someId');");

You can find more documentation on this here, in the documenation, or, preferably, in the JavaDocs of JavascriptExecutor.

The executeScript() takes function calls and raw JS, too. You can return a value from it and you can pass lots of complicated arguments to it, some random examples:

  1. // returns the right WebElement
    // it's the same as driver.findElement(By.id("someId"))
    js.executeScript("return document.getElementById('someId');");
    
  2. // draws a border around WebElement
    WebElement element = driver.findElement(By.anything("tada"));
    js.executeScript("arguments[0].style.border='3px solid red'", element);
    
  3. // changes all input elements on the page to radio buttons
    js.executeScript(
            "var inputs = document.getElementsByTagName('input');" +
            "for(var i = 0; i < inputs.length; i++) { " +
            "    inputs[i].type = 'radio';" +
            "}" );
    

Creating a new dictionary in Python

So there 2 ways to create a dict :

  1. my_dict = dict()

  2. my_dict = {}

But out of these two options {} is more efficient than dict() plus its readable. CHECK HERE

Right way to convert data.frame to a numeric matrix, when df also contains strings?

Here is an alternative way if the data frame just contains numbers.

_x000D_
_x000D_
apply(as.matrix.noquote(SFI),2,as.numeric)
_x000D_
_x000D_
_x000D_

but the most reliable way of converting a data frame to a matrix is using data.matrix() function.

Execute JavaScript code stored as a string

Checked this on many complex and obfuscated scripts:

var js = "alert('Hello, World!');" // put your JS code here
var oScript = document.createElement("script");
var oScriptText = document.createTextNode(js);
oScript.appendChild(oScriptText);
document.body.appendChild(oScript);

Arrays.fill with multidimensional array in Java

Using Java 8, you can declare and initialize a two-dimensional array without using a (explicit) loop as follows:

int x = 20; // first dimension
int y = 4; // second dimension

double[][] a = IntStream.range(0, x)
                        .mapToObj(i -> new double[y])
                        .toArray(i -> new double[x][]);

This will initialize the arrays with default values (0.0 in the case of double).

In case you want to explicitly define the fill value to be used, You can add in a DoubleStream:

int x = 20; // first dimension
int y = 4; // second dimension
double v = 5.0; // fill value

double[][] a = IntStream
        .range(0, x)
        .mapToObj(i -> DoubleStream.generate(() -> v).limit(y).toArray())
        .toArray(i -> new double[x][]);

Insert node at a certain position in a linked list C++

Node* InsertNth(int data, int position)
{
  struct Node *n=new struct Node;
  n->data=data;  
  if(position==0)
  {// this will also cover insertion at head (if there is no problem with the input)

      n->next=head;
      head=n;
  }

  else
  {
      struct Node *c=new struct Node;
      int count=1;
      c=head;
      while(count!=position)
      {
          c=c->next;
          count++;
      }
      n->next=c->next;
      c->next=n;

  }
    return ;
}

How to count number of files in each directory?

find . -type f | cut -d/ -f2 | sort | uniq -c
  • find. -type f to find all items of the type file
  • cut -d/ -f2 to cut out their specific folder
  • sort to sort the list of foldernames
  • uniq -c to return the number of times each foldername has been counted

getContext is not a function

Your value:

this.element = $(id);

is a jQuery object, not a pure Canvas element.

To turn it back so you can call getContext(), call this.element.get(0), or better yet store the real element and not the jQuery object:

function canvasLayer(location, id) {

    this.width = $(window).width();
    this.height = $(window).height();
    this.element = document.createElement('canvas');

    $(this.element)
       .attr('id', id)
       .text('unsupported browser')
       .attr('width', this.width)       // for pixels
       .attr('height', this.height)
       .width(this.width)               // for CSS scaling
       .height(this.height)
       .appendTo(location);

    this.context = this.element.getContext("2d");
}

See running code at http://jsfiddle.net/alnitak/zbaMh/, ideally using the Chrome Javascript Console so you can see the resulting object in the debug output.

Procedure expects parameter which was not supplied

If Template is not set (i.e. ==null), this error will be raised, too.

More comments:

If you know the parameter value by the time you add parameters, you can also use AddWithValue

The EXEC is not required. You can reference the @template parameter in the SELECT directly.

Adding a custom header to HTTP request using angular.js

If you want to add your custom headers to ALL requests, you can change the defaults on $httpProvider to always add this header…

app.config(['$httpProvider', function ($httpProvider) {
    $httpProvider.defaults.headers.common = { 
        'Authorization': 'Basic d2VudHdvcnRobWFuOkNoYW5nZV9tZQ==',
        'Accept': 'application/json;odata=verbose'
      };
}]);

How do I detect "shift+enter" and generate a new line in Textarea?

Easy & Elegant solution:

First, pressing Enter inside a textarea does not submit the form unless you have script to make it do that. That's the behaviour the user expects and I'd recommend against changing it. However, if you must do this, the easiest approach would be to find the script that is making Enter submit the form and change it. The code will have something like

if (evt.keyCode == 13) {
    form.submit();
}

... and you could just change it to

if (evt.keyCode == 13 && !evt.shiftKey) {
    form.submit();
}

On the other hand, if you don't have access to this code for some reason, you need to do the following to make it work in all major browsers even if the caret is not at the end of the text:

jsFiddle: http://jsfiddle.net/zd3gA/1/

Code:

function pasteIntoInput(el, text) {
    el.focus();
    if (typeof el.selectionStart == "number"
            && typeof el.selectionEnd == "number") {
        var val = el.value;
        var selStart = el.selectionStart;
        el.value = val.slice(0, selStart) + text + val.slice(el.selectionEnd);
        el.selectionEnd = el.selectionStart = selStart + text.length;
    } else if (typeof document.selection != "undefined") {
        var textRange = document.selection.createRange();
        textRange.text = text;
        textRange.collapse(false);
        textRange.select();
    }
}

function handleEnter(evt) {
    if (evt.keyCode == 13 && evt.shiftKey) {
        if (evt.type == "keypress") {
            pasteIntoInput(this, "\n");
        }
        evt.preventDefault();
    }
}

// Handle both keydown and keypress for Opera, which only allows default
// key action to be suppressed in keypress
$("#your_textarea_id").keydown(handleEnter).keypress(handleEnter);

Foreign keys in mongo?

We can define the so-called foreign key in MongoDB. However, we need to maintain the data integrity BY OURSELVES. For example,

student
{ 
  _id: ObjectId(...),
  name: 'Jane',
  courses: ['bio101', 'bio102']   // <= ids of the courses
}

course
{
  _id: 'bio101',
  name: 'Biology 101',
  description: 'Introduction to biology'
}

The courses field contains _ids of courses. It is easy to define a one-to-many relationship. However, if we want to retrieve the course names of student Jane, we need to perform another operation to retrieve the course document via _id.

If the course bio101 is removed, we need to perform another operation to update the courses field in the student document.

More: MongoDB Schema Design

The document-typed nature of MongoDB supports flexible ways to define relationships. To define a one-to-many relationship:

Embedded document

  1. Suitable for one-to-few.
  2. Advantage: no need to perform additional queries to another document.
  3. Disadvantage: cannot manage the entity of embedded documents individually.

Example:

student
{
  name: 'Kate Monster',
  addresses : [
     { street: '123 Sesame St', city: 'Anytown', cc: 'USA' },
     { street: '123 Avenue Q', city: 'New York', cc: 'USA' }
  ]
}

Child referencing

Like the student/course example above.

Parent referencing

Suitable for one-to-squillions, such as log messages.

host
{
    _id : ObjectID('AAAB'),
    name : 'goofy.example.com',
    ipaddr : '127.66.66.66'
}

logmsg
{
    time : ISODate("2014-03-28T09:42:41.382Z"),
    message : 'cpu is on fire!',
    host: ObjectID('AAAB')       // Reference to the Host document
}

Virtually, a host is the parent of a logmsg. Referencing to the host id saves much space given that the log messages are squillions.

References:

  1. 6 Rules of Thumb for MongoDB Schema Design: Part 1
  2. 6 Rules of Thumb for MongoDB Schema Design: Part 2
  3. 6 Rules of Thumb for MongoDB Schema Design: Part 3
  4. Model One-to-Many Relationships with Document References

AngularJS $http-post - convert binary to excel file and download

Answer No 5 worked for me ,Suggestion to developer who are facing similar issue.

//////////////////////////////////////////////////////////
//Server side 
//////////////////////////////////////////////////////////
imports ***
public class AgentExcelBuilder extends AbstractExcelView {

protected void buildExcelDocument(Map<String, Object> model,
            HSSFWorkbook workbook, HttpServletRequest request,
            HttpServletResponse response) throws Exception {

        //poi code goes here ....

        response.setHeader("Cache-Control","must-revalidate");
        response.setHeader("Pragma", "public");
        response.setHeader("Content-Transfer-Encoding","binary");
        response.setHeader("Content-disposition", "attachment; filename=test.xls");

        OutputStream output = response.getOutputStream();

        workbook.write(output);
        System.out.println(workbook.getActiveSheetIndex());
        System.out.println(workbook.getNumberOfSheets());
        System.out.println(workbook.getNumberOfNames());
        output.flush();
        output.close(); 
}//method buildExcelDocument ENDS

//service.js at angular JS code
function getAgentInfoExcel(workgroup,callback){
        $http({
            url: CONTEXT_PATH+'/rest/getADInfoExcel',
            method: "POST",
            data: workgroup, //this is your json data string
            headers: {
               'Content-type': 'application/json'
            },
            responseType: 'arraybuffer'
        }).success(function (data, status, headers, config) {
            var blob = new Blob([data], {type: "application/vnd.ms-excel"});
            var objectUrl = URL.createObjectURL(blob);
            window.open(objectUrl);
        }).error(function (data, status, headers, config) {
            console.log('Failed to download Excel')
        });
    }
////////////////////////////////in .html 

<div class="form-group">`enter code here`
                                <a href="javascript:void(0)" class="fa fa-file-excel-o"
                                    ng-click="exportToExcel();"> Agent Export</a>
                            </div>

How to play a sound in C#, .NET

You can use SystemSound, for example, System.Media.SystemSounds.Asterisk.Play();.

What is the difference between x86 and x64

If you download Java Development Kit(JDK) then there is a difference as it contains native libraries which differ for different architectures:

  • x86 is for 32-bit OS
  • x64 is for 64-bit OS

In addition you can use 32-bit JDK(x86) on 64-bit OS. But you can not use 64-bit JDK on 32-bit OS.

At the same time you can run compiled Java classes on any JVM. It does not matter whether it 32 or 64-bit.

Eclipse fonts and background color

I just came across this: Eclipse Colour Themes

Install the plugin and choose from a selection of pre-defined themes, or write your own. Just what I needed!

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

Somehow the MySQL server process did not create the socket, or the client is looking for the socket in the wrong place.

My first suggestion would be to check if the MySQL server is running. Second suggestion might be, is the MySQL server running on another host? If so, add the -h <hostname> flag to your MySQL client in the terminal.

If MySQL is indeed running, and running locally, check your my.cnf file. There should be a line like

socket = /var/run/mysqld/mysqld.sock

See if that matches the socket location that you mentioned in your post.

From experience, I would say the most likely scenario is your MySQL server either is not running at all or is not running on the same host as where you run your MySQL client from the terminal.

Angular 2 - Using 'this' inside setTimeout

You need to use Arrow function ()=> ES6 feature to preserve this context within setTimeout.

// var that = this;                             // no need of this line
this.messageSuccess = true;

setTimeout(()=>{                           //<<<---using ()=> syntax
      this.messageSuccess = false;
 }, 3000);

`export const` vs. `export default` in ES6

export default affects the syntax when importing the exported "thing", when allowing to import, whatever has been exported, by choosing the name in the import itself, no matter what was the name when it was exported, simply because it's marked as the "default".

A useful use case, which I like (and use), is allowing to export an anonymous function without explicitly having to name it, and only when that function is imported, it must be given a name:


Example:

Export 2 functions, one is default:

export function divide( x ){
    return x / 2;
}

// only one 'default' function may be exported and the rest (above) must be named
export default function( x ){  // <---- declared as a default function
    return x * x;
}

Import the above functions. Making up a name for the default one:

// The default function should be the first to import (and named whatever)
import square, {divide} from './module_1.js'; // I named the default "square" 

console.log( square(2), divide(2) ); // 4, 1

When the {} syntax is used to import a function (or variable) it means that whatever is imported was already named when exported, so one must import it by the exact same name, or else the import wouldn't work.


Erroneous Examples:

  1. The default function must be first to import

    import {divide}, square from './module_1.js
    
  2. divide_1 was not exported in module_1.js, thus nothing will be imported

    import {divide_1} from './module_1.js
    
  3. square was not exported in module_1.js, because {} tells the engine to explicitly search for named exports only.

    import {square} from './module_1.js
    

how to get all markers on google-maps-v3

If you mean "how can I get a reference to all markers on a given map" - then I think the answer is "Sorry, you have to do it yourself". I don't think there is any handy "maps.getMarkers()" type function: you have to keep your own references as the points are created:

var allMarkers = [];
....
// Create some markers
for(var i = 0; i < 10; i++) {
    var marker = new google.maps.Marker({...});
    allMarkers.push(marker);
}
...

Then you can loop over the allMarkers array to and do whatever you need to do.

How do I force Maven to use my local repository rather than going out to remote repos to retrieve artifacts?

In my case I had a multi module project just like you. I had to change a group Id of one of the external libraries my project was depending on as shown below.

From:

<dependencyManagement>
    <dependency>
        <groupId>org.thirdparty</groupId>
        <artifactId>calculation-api</artifactId>
        <version>2.0</version>
        <type>jar</type>
        <scope>provided</scope>
    </dependency>
<dependencyManagement>

To:

<dependencyManagement>
   <dependency>
      <groupId>org.thirdparty.module</groupId>
        <artifactId>calculation-api</artifactId>
        <version>2.0</version>
        <type>jar</type>
        <scope>provided</scope>
    </dependency>
<dependencyManagement>

Pay attention to the <groupId> section. It turned out that I was forgetting to modifiy the corresponding section of the submodules that define this dependency in their pom files.

It drove me very crazy because the module was available locally.

using "if" and "else" Stored Procedures MySQL

I think that this construct: if exists (select... is specific for MS SQL. In MySQL EXISTS predicate tells you whether the subquery finds any rows and it's used like this: SELECT column1 FROM t1 WHERE EXISTS (SELECT * FROM t2);

You can rewrite the above lines of code like this:

DELIMITER $$

CREATE PROCEDURE `checando`(in nombrecillo varchar(30), in contrilla varchar(30), out resultado int)

BEGIN
    DECLARE count_prim INT;
    DECLARE count_sec INT;

    SELECT COUNT(*) INTO count_prim FROM compas WHERE nombre = nombrecillo AND contrasenia = contrilla;
    SELECT COUNT(*) INTO count_sec FROM FROM compas WHERE nombre = nombrecillo;

    if (count_prim > 0) then
        set resultado = 0;
    elseif (count_sec > 0) then
        set resultado = -1;
    else 
        set resultado = -2;
    end if;
    SELECT resultado;
END

Calling the base class constructor from the derived class constructor

but I can't initialize my derived class, I mean I did this Inheritance so I can add animals to my PetStore but now since sizeF is private how can I do that ?? so I'm thinking maybe in the PetStore default constructor I can call Farm()... so any Idea ???

Don't panic.

Farm constructor will be called in the constructor of PetStore, automatically.

See the base class inheritance calling rules: What are the rules for calling the superclass constructor?

ASP.NET MVC controller actions that return JSON or partial html

In your action method, return Json(object) to return JSON to your page.

public ActionResult SomeActionMethod() {
  return Json(new {foo="bar", baz="Blech"});
}

Then just call the action method using Ajax. You could use one of the helper methods from the ViewPage such as

<%= Ajax.ActionLink("SomeActionMethod", new AjaxOptions {OnSuccess="somemethod"}) %>

SomeMethod would be a javascript method that then evaluates the Json object returned.

If you want to return a plain string, you can just use the ContentResult:

public ActionResult SomeActionMethod() {
    return Content("hello world!");
}

ContentResult by default returns a text/plain as its contentType.
This is overloadable so you can also do:

return Content("<xml>This is poorly formatted xml.</xml>", "text/xml");

sed command with -i option failing on Mac, but works on Linux

Or, you can install the GNU version of sed in your Mac, called gsed, and use it using the standard Linux syntax.

For that, install gsed using ports (if you don't have it, get it at http://www.macports.org/) by running sudo port install gsed. Then, you can run sed -i 's/old_link/new_link/g' *

How to show Bootstrap table with sort icon

Use this icons with bootstrap (glyphicon):

<span class="glyphicon glyphicon-triangle-bottom"></span>
<span class="glyphicon glyphicon-triangle-top"></span>

http://www.w3schools.com/bootstrap/tryit.asp?filename=trybs_ref_glyph_triangle-bottom&stacked=h

http://www.w3schools.com/bootstrap/tryit.asp?filename=trybs_ref_glyph_triangle-bottom&stacked=h

jQuery see if any or no checkboxes are selected

This is the best way to solve this problem.

  if($("#checkbox").is(":checked")){

  // Do something here /////

  };

No Access-Control-Allow-Origin header is present on the requested resource

On your servlet simply override the service method of your servlet so that you can add headers for all your http methods (POST, GET, DELETE, PUT, etc...).

@Override
    protected void service(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {

        if(("http://www.example.com").equals(req.getHeader("origin"))){
            res.setHeader("Access-Control-Allow-Origin", req.getHeader("origin"));
            res.setHeader("Access-Control-Allow-Headers", "Authorization");
        }

        super.service(req, res);
    }

How Do I Insert a Byte[] Into an SQL Server VARBINARY Column

Try this:

"0x" + BitConverter.ToString(arraytoinsert).Replace("-", "")

Although you should really be using a parameterised query rather than string concatenation of course...

getting integer values from textfield

You need to use Integer.parseInt(String)

private void jTextField2MouseClicked(java.awt.event.MouseEvent evt) {
        if(evt.getSource()==jTextField2){
            int jml = Integer.parseInt(jTextField3.getText());
            jTextField1.setText(numberToWord(jml));

        }
    }

How to run docker-compose up -d at system start up?

When we use crontab or the deprecated /etc/rc.local file, we need a delay (e.g. sleep 10, depending on the machine) to make sure that system services are available. Usually, systemd (or upstart) is used to manage which services start when the system boots. You can try use the similar configuration for this:

# /etc/systemd/system/docker-compose-app.service

[Unit]
Description=Docker Compose Application Service
Requires=docker.service
After=docker.service

[Service]
Type=oneshot
RemainAfterExit=yes
WorkingDirectory=/srv/docker
ExecStart=/usr/local/bin/docker-compose up -d
ExecStop=/usr/local/bin/docker-compose down
TimeoutStartSec=0

[Install]
WantedBy=multi-user.target

Or, if you want run without the -d flag:

# /etc/systemd/system/docker-compose-app.service

[Unit]
Description=Docker Compose Application Service
Requires=docker.service
After=docker.service

[Service]
WorkingDirectory=/srv/docker
ExecStart=/usr/local/bin/docker-compose up
ExecStop=/usr/local/bin/docker-compose down
TimeoutStartSec=0
Restart=on-failure
StartLimitIntervalSec=60
StartLimitBurst=3

[Install]
WantedBy=multi-user.target

Change the WorkingDirectory parameter with your dockerized project path. And enable the service to start automatically:

systemctl enable docker-compose-app

Remove duplicated rows using dplyr

Here is a solution using dplyr >= 0.5.

library(dplyr)
set.seed(123)
df <- data.frame(
  x = sample(0:1, 10, replace = T),
  y = sample(0:1, 10, replace = T),
  z = 1:10
)

> df %>% distinct(x, y, .keep_all = TRUE)
    x y z
  1 0 1 1
  2 1 0 2
  3 1 1 4

Batch file for PuTTY/PSFTP file transfer automation

You need to store the psftp script (lines from open to bye) into a separate file and pass that to psftp using -b switch:

cd "C:\Program Files (x86)\PuTTY"
psftp -b "C:\path\to\script\script.txt"

Reference:
https://the.earth.li/~sgtatham/putty/latest/htmldoc/Chapter6.html#psftp-option-b


EDIT: For username+password: As you cannot use psftp commands in a batch file, for the same reason, you cannot specify the username and the password as psftp commands. These are inputs to the open command. While you can specify the username with the open command (open <user>@<IP>), you cannot specify the password this way. This can be done on a psftp command line only. Then it's probably cleaner to do all on the command-line:

cd "C:\Program Files (x86)\PuTTY"
psftp -b script.txt <user>@<IP> -pw <PW>

And remove the open, <user> and <PW> lines from your script.txt.

Reference:
https://the.earth.li/~sgtatham/putty/latest/htmldoc/Chapter6.html#psftp-starting
https://the.earth.li/~sgtatham/putty/latest/htmldoc/Chapter3.html#using-cmdline-pw


What you are doing atm is that you run psftp without any parameter or commands. Once you exit it (like by typing bye), your batch file continues trying to run open command (and others), what Windows shell obviously does not understand.


If you really want to keep everything in one file (the batch file), you can write commands to psftp standard input, like:

(
    echo cd ...
    echo lcd ...
    echo put log.sh
) | psftp -b script.txt <user>@<IP> -pw <PW>

What does <> mean?

"Does not equal"

Excel - Button to go to a certain sheet

Alternately, if you are using a Macro Enabled workbook:

Add any control at all from the Developer -> Insert (Probably a button)

When it asks what Macro to assign, choose New. For the code for the generated module enter something like:

Thisworkbook.Sheets("Sheet Name").Activate

However, if you are not using Macros in your work book. Ooo's approach is definitely surperior as hyperlinks will work with no need to trust the document.

Should I declare Jackson's ObjectMapper as a static field?

Although it is safe to declare a static ObjectMapper in terms of thread safety, you should be aware that constructing static Object variables in Java is considered bad practice. For more details, see Why are static variables considered evil? (and if you'd like, my answer)

In short, statics should be avoided because the make it difficult to write concise unit tests. For example, with a static final ObjectMapper, you can't swap out the JSON serialization for dummy code or a no-op.

In addition, a static final prevents you from ever reconfiguring ObjectMapper at runtime. You might not envision a reason for that now, but if you lock yourself into a static final pattern, nothing short of tearing down the classloader will let you re-initialize it.

In the case of ObjectMapper its fine, but in general it is bad practice and there is no advantage over using a singleton pattern or inversion-of-control to manage your long-lived objects.

How to refresh an IFrame using Javascript?

Got this from here

var f = document.getElementById('iframe1');
f.src = f.src;

Package php5 have no installation candidate (Ubuntu 16.04)

This worked for me.

sudo apt-get update
sudo apt-get install lamp-server^ -y

;)

glm rotate usage in Opengl

GLM has good example of rotation : http://glm.g-truc.net/code.html

glm::mat4 Projection = glm::perspective(45.0f, 4.0f / 3.0f, 0.1f, 100.f);
glm::mat4 ViewTranslate = glm::translate(
    glm::mat4(1.0f),
    glm::vec3(0.0f, 0.0f, -Translate)
);
glm::mat4 ViewRotateX = glm::rotate(
    ViewTranslate,
    Rotate.y,
    glm::vec3(-1.0f, 0.0f, 0.0f)
);
glm::mat4 View = glm::rotate(
    ViewRotateX,
    Rotate.x,
    glm::vec3(0.0f, 1.0f, 0.0f)
);
glm::mat4 Model = glm::scale(
    glm::mat4(1.0f),
    glm::vec3(0.5f)
);
glm::mat4 MVP = Projection * View * Model;
glUniformMatrix4fv(LocationMVP, 1, GL_FALSE, glm::value_ptr(MVP));

Fetch API with Cookie

Just adding to the correct answers here for .net webapi2 users.

If you are using cors because your client site is served from a different address as your webapi then you need to also include SupportsCredentials=true on the server side configuration.

        // Access-Control-Allow-Origin
        // https://docs.microsoft.com/en-us/aspnet/web-api/overview/security/enabling-cross-origin-requests-in-web-api
        var cors = new EnableCorsAttribute(Settings.CORSSites,"*", "*");
        cors.SupportsCredentials = true;
        config.EnableCors(cors);

npm ERR! code UNABLE_TO_GET_ISSUER_CERT_LOCALLY

The below code worked for me perfectly here make http only instead https

npm config set registry http://registry.npmjs.org/  

Javascript regular expression password validation having special characters

Regex for password:

/^(?=.*\d)(?=.*[A-Z])(?=.*[a-z])(?=.*[a-zA-Z!#$%&? "])[a-zA-Z0-9!#$%&?]{8,20}$/

Took me a while to figure out the restrictions, but I did it!

Restrictions: (Note: I have used >> and << to show the important characters)

  1. Minimum 8 characters {>>8,20}
  2. Maximum 20 characters {8,>>20}
  3. At least one uppercase character (?=.*[A-Z])
  4. At least one lowercase character (?=.*[a-z])
  5. At least one digit (?=.*\d)
  6. At least one special character (?=.*[a-zA-Z >>!#$%&? "<<])[a-zA-Z0-9 >>!#$%&?<< ]

nginx- duplicate default server error

In my case junk files from editor caused the problem. I had a config as below:

#...
http {
 # ...
 include ../sites/*;
}

In the ../sites directory initially I had a default.config file. However, by mistake I saved duplicate files as default.config.save and default.config.save.1. Removing them resolved the issue.

Call a function after previous function is complete

If method 1 has to be executed after method 2, 3, 4. The following code snippet can be the solution for this using Deferred object in JavaScript.

_x000D_
_x000D_
function method1(){_x000D_
  var dfd = new $.Deferred();_x000D_
     setTimeout(function(){_x000D_
     console.log("Inside Method - 1"); _x000D_
     method2(dfd);  _x000D_
    }, 5000);_x000D_
  return dfd.promise();_x000D_
}_x000D_
_x000D_
function method2(dfd){_x000D_
  setTimeout(function(){_x000D_
   console.log("Inside Method - 2"); _x000D_
   method3(dfd); _x000D_
  }, 3000);_x000D_
}_x000D_
_x000D_
function method3(dfd){_x000D_
  setTimeout(function(){_x000D_
   console.log("Inside Method - 3");  _x000D_
   dfd.resolve();_x000D_
  }, 3000);_x000D_
}_x000D_
_x000D_
function method4(){   _x000D_
   console.log("Inside Method - 4");  _x000D_
}_x000D_
_x000D_
var call = method1();_x000D_
_x000D_
$.when(call).then(function(cb){_x000D_
  method4();_x000D_
});
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
_x000D_
_x000D_
_x000D_

Setting up JUnit with IntelliJ IDEA

  1. Create and setup a "tests" folder
    • In the Project sidebar on the left, right-click your project and do New > Directory. Name it "test" or whatever you like.
    • Right-click the folder and choose "Mark Directory As > Test Source Root".
  2. Adding JUnit library
    • Right-click your project and choose "Open Module Settings" or hit F4. (Alternatively, File > Project Structure, Ctrl-Alt-Shift-S is probably the "right" way to do this)
    • Go to the "Libraries" group, click the little green plus (look up), and choose "From Maven...".
    • Search for "junit" -- you're looking for something like "junit:junit:4.11".
    • Check whichever boxes you want (Sources, JavaDocs) then hit OK.
    • Keep hitting OK until you're back to the code.
  3. Write your first unit test

    • Right-click on your test folder, "New > Java Class", call it whatever, e.g. MyFirstTest.
    • Write a JUnit test -- here's mine:

      import org.junit.Assert;
      import org.junit.Test;
      
      public class MyFirstTest {
          @Test
          public void firstTest() {
              Assert.assertTrue(true);
          }
      }
      
  4. Run your tests
    • Right-click on your test folder and choose "Run 'All Tests'". Presto, testo.
    • To run again, you can either hit the green "Play"-style button that appeared in the new section that popped on the bottom of your window, or you can hit the green "Play"-style button in the top bar.

Identifying Exception Type in a handler Catch Block

Alternative Solution

Instead halting a debug session to add some throw-away statements to then recompile and restart, why not just use the debugger to answer that question immediately when a breakpoint is hit?

That can be done by opening up the Immediate Window of the debugger and typing a GetType off of the exception and hitting Enter. The immediate window also allows one to interrogate variables as needed.

See VS Docs: Immediate Window


For example I needed to know what the exception was and just extracted the Name property of GetType as such without having to recompile:

enter image description here

What's the syntax to import a class in a default package in Java?

The only way to access classes in the default package is from another class in the default package. In that case, don't bother to import it, just refer to it directly.

Why is Tkinter Entry's get function returning nothing?

A simple example without classes:

from tkinter import *    
master = Tk()

# Create this method before you create the entry
def return_entry(en):
    """Gets and prints the content of the entry"""
    content = entry.get()
    print(content)  

Label(master, text="Input: ").grid(row=0, sticky=W)

entry = Entry(master)
entry.grid(row=0, column=1)

# Connect the entry with the return button
entry.bind('<Return>', return_entry) 

mainloop()

assign headers based on existing row in dataframe in R

Very similar to Vishnu's answer but uses the lapply to map all the data to characters then to assign them as the headers. This is really helpful if your data is imported as factors.

DF[] <- lapply(DF, as.character)
colnames(DF) <- DF[1, ]
DF <- DF[-1 ,]

note that that if you have a lot of numeric data or factors you want you'll need to convert them back. In this case it may make sense to store the character data frame, extract the row you want, and then apply it to the original data frame

tempDF <- DF
tempDF[] <- lapply(DF, as.character)
colnames(DF) <- tempDF[1, ]
DF <- DF[-1 ,]
tempDF <- NULL

Android: how to make keyboard enter button say "Search" and handle its click?

Hide keyboard when user clicks search. Addition to Robby Pond answer

private void performSearch() {
    editText.clearFocus();
    InputMethodManager in = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
    in.hideSoftInputFromWindow(editText.getWindowToken(), 0);
    //...perform search
}

How to fix "set SameSite cookie to none" warning?

I ended up fixing our Ubuntu 18.04 / Apache 2.4.29 / PHP 7.2 install for Chrome 80 by installing mod_headers:

a2enmod headers

Adding the following directive to our Apache VirtualHost configurations:

Header edit Set-Cookie ^(.*)$ "$1; Secure; SameSite=None"

And restarting Apache:

service apache2 restart

In reviewing the docs (http://www.balkangreenfoundation.org/manual/en/mod/mod_headers.html) I noticed the "always" condition has certain situations where it does not work from the same pool of response headers. Thus not using "always" is what worked for me with PHP but the docs suggest that if you want to cover all your bases you could add the directive both with and without "always". I have not tested that.

Javascript: Load an Image from url and display

When the button is clicked, get the value of the input and use it to create an image element which is appended to the body (or anywhere else) :

<html>
<body>
<form>
    <input type="text" id="imagename" value="" />
    <input type="button" id="btn" value="GO" />
</form>
    <script type="text/javascript">
        document.getElementById('btn').onclick = function() {
            var val = document.getElementById('imagename').value,
                src = 'http://webpage.com/images/' + val +'.png',
                img = document.createElement('img');

            img.src = src;
            document.body.appendChild(img);
        }
    </script>
</body>
</html>

FIDDLE

the same in jQuery:

$('#btn').on('click', function() {
    var img = $('<img />', {src : 'http://webpage.com/images/' + $('#imagename').val() +'.png'});
    img.appendTo('body');
});

How to return a struct from a function in C++?

Here is an edited version of your code which is based on ISO C++ and which works well with G++:

#include <string.h>
#include <iostream>
using namespace std;

#define NO_OF_TEST 1

struct studentType {
    string studentID;
    string firstName;
    string lastName;
    string subjectName;
    string courseGrade;
    int arrayMarks[4];
    double avgMarks;
};

studentType input() {
    studentType newStudent;
    cout << "\nPlease enter student information:\n";

    cout << "\nFirst Name: ";
    cin >> newStudent.firstName;

    cout << "\nLast Name: ";
    cin >> newStudent.lastName;

    cout << "\nStudent ID: ";
    cin >> newStudent.studentID;

    cout << "\nSubject Name: ";
    cin >> newStudent.subjectName;

    for (int i = 0; i < NO_OF_TEST; i++) {
        cout << "\nTest " << i+1 << " mark: ";
        cin >> newStudent.arrayMarks[i];
    }

    return newStudent;
}

int main() {
    studentType s;
    s = input();

    cout <<"\n========"<< endl << "Collected the details of "
        << s.firstName << endl;

    return 0;
}

keypress, ctrl+c (or some combo like that)

There is a plugin for Jquery called "Hotkeys" which allows you to bind to key down combinations.

Does this do what you are after?

Jquery HotKeys - Google Code

Running Python on Windows for Node.js dependencies

The right way is 1) Download and Install python 2.7.14 from here. 2) Set environment variable for python from here.

done!

note: Please set environment variable accordingly. I answered here for windows.

Logical operator in a handlebars.js {{#if}} conditional

I can understand why you would want to create a helper for situations where you have a large number of varied comparisons to perform within your template, but for a relatively small number of comparisons (or even one, which was what brought me to this page in the first place), it would probably just be easier to define a new handlebars variable in your view-rendering function call, like:

Pass to handlebars on render:

var context= {
    'section1' : section1,
    'section2' : section2,
    'section1or2' : (section1)||(section2)
};

and then within your handlebars template:

{{#if section1or2}}
    .. content
{{/if}}

I mention this for simplicity's sake, and also because it's an answer that may be quick and helpful while still complying with the logicless nature of Handlebars.

Better way to call javascript function in a tag

Some advantages to the second option:

  1. You can use this inside onclick to reference the anchor itself (doing the same in option 1 will give you window instead).

  2. You can set the href to a non-JS compatible URL to support older browsers (or those that have JS disabled); browsers that support JavaScript will execute the function instead (to stay on the page you have to use onclick="return someFunction();" and return false from inside the function or onclick="return someFunction(); return false;" to prevent default action).

  3. I've seen weird stuff happen when using href="javascript:someFunction()" and the function returns a value; the whole page would get replaced by just that value.

Pitfalls

Inline code:

  1. Runs in document scope as opposed to code defined inside <script> tags which runs in window scope; therefore, symbols may be resolved based on an element's name or id attribute, causing the unintended effect of attempting to treat an element as a function.

  2. Is harder to reuse; delicate copy-paste is required to move it from one project to another.

  3. Adds weight to your pages, whereas external code files can be cached by the browser.

Checking if a key exists in a JavaScript object?

const object1 = {
  a: 'something',
  b: 'something',
  c: 'something'
};

const key = 's';

// Object.keys(object1) will return array of the object keys ['a', 'b', 'c']

Object.keys(object1).indexOf(key) === -1 ? 'the key is not there' : 'yep the key is exist';

Error loading MySQLdb Module 'Did you install mysqlclient or MySQL-python?'

This command did the trick from @Aniket Sinha's answer above:

pip install mysqlclient

What is a Python egg?

The .egg file is a distribution format for Python packages. It’s just an alternative to a source code distribution or Windows exe. But note that for pure Python, the .egg file is completely cross-platform.

The .egg file itself is essentially a .zip file. If you change the extension to “zip”, you can see that it will have folders inside the archive.

Also, if you have an .egg file, you can install it as a package using easy_install

Example: To create an .egg file for a directory say mymath which itself may have several python scripts, do the following step:

# setup.py
from setuptools import setup, find_packages
setup(
    name = "mymath",
    version = "0.1",
    packages = find_packages()
    )

Then, from the terminal do:

 $ python setup.py bdist_egg

This will generate lot of outputs, but when it’s completed you’ll see that you have three new folders: build, dist, and mymath.egg-info. The only folder that we care about is the dist folder where you'll find your .egg file, mymath-0.1-py3.5.egg with your default python (installation) version number(mine here: 3.5)

Source: Python library blog

What are my options for storing data when using React Native? (iOS and Android)

Quick and dirty: just use Redux + react-redux + redux-persist + AsyncStorage for react-native.

It fits almost perfectly the react native world and works like a charm for both android and ios. Also, there is a solid community around it, and plenty of information.

For a working example, see the F8App from Facebook.

What are the different options for data persistence?

With react native, you probably want to use redux and redux-persist. It can use multiple storage engines. AsyncStorage and redux-persist-filesystem-storage are the options for RN.

There are other options like Firebase or Realm, but I never used those on a RN project.

For each, what are the limits of that persistence (i.e., when is the data no longer available)? For example: when closing the application, restarting the phone, etc.

Using redux + redux-persist you can define what is persisted and what is not. When not persisted, data exists while the app is running. When persisted, the data persists between app executions (close, open, restart phone, etc).

AsyncStorage has a default limit of 6MB on Android. It is possible to configure a larger limit (on Java code) or use redux-persist-filesystem-storage as storage engine for Android.

For each, are there differences (other than general setup) between implementing in iOS vs Android?

Using redux + redux-persist + AsyncStorage the setup is exactly the same on android and iOS.

How do the options compare for accessing data offline? (or how is offline access typically handled?)

Using redux, offiline access is almost automatic thanks to its design parts (action creators and reducers).

All data you fetched and stored are available, you can easily store extra data to indicate the state (fetching, success, error) and the time it was fetched. Normally, requesting a fetch does not invalidate older data and your components just update when new data is received.

The same apply in the other direction. You can store data you are sending to server and that are still pending and handle it accordingly.

Are there any other considerations I should keep in mind?

React promotes a reactive way of creating apps and Redux fits very well on it. You should try it before just using an option you would use in your regular Android or iOS app. Also, you will find much more docs and help for those.

What is the opposite of evt.preventDefault();

You can always use this attached to some click event in your script:

location.href = this.href;

example of usage is:

jQuery('a').click(function(e) {
    location.href = this.href;
});

Create a folder inside documents folder in iOS apps

Swift 3 Solution:

private func createImagesFolder() {
        // path to documents directory
        let documentDirectoryPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first
        if let documentDirectoryPath = documentDirectoryPath {
            // create the custom folder path
            let imagesDirectoryPath = documentDirectoryPath.appending("/images")
            let fileManager = FileManager.default
            if !fileManager.fileExists(atPath: imagesDirectoryPath) {
                do {
                    try fileManager.createDirectory(atPath: imagesDirectoryPath,
                                                    withIntermediateDirectories: false,
                                                    attributes: nil)
                } catch {
                    print("Error creating images folder in documents dir: \(error)")
                }
            }
        }
    }

Angular 4/5/6 Global Variables

You can access Globals entity from any point of your App via Angular dependency injection. If you want to output Globals.role value in some component's template, you should inject Globals through the component's constructor like any service:

// hello.component.ts
import { Component } from '@angular/core';
import { Globals } from './globals';

@Component({
  selector: 'hello',
  template: 'The global role is {{globals.role}}',
  providers: [ Globals ] // this depends on situation, see below
})

export class HelloComponent {
  constructor(public globals: Globals) {}
}

I provided Globals in the HelloComponent, but instead it could be provided in some HelloComponent's parent component or even in AppModule. It will not matter until your Globals has only static data that could not be changed (say, constants only). But if it's not true and for example different components/services might want to change that data, then the Globals must be a singleton. In that case it should be provided in the topmost level of the hierarchy where it is going to be used. Let's say this is AppModule:

import { Globals } from './globals'

@NgModule({
  // ... imports, declarations etc
  providers: [
    // ... other global providers
    Globals // so do not provide it into another components/services if you want it to be a singleton
  ]
})

Also, it's impossible to use var the way you did, it should be

// globals.ts
import { Injectable } from '@angular/core';

@Injectable()
export class Globals {
  role: string = 'test';
}

Update

At last, I created a simple demo on stackblitz, where single Globals is being shared between 3 components and one of them can change the value of Globals.role.

Pad with leading zeros

There's no such concept as an integer with padding. How many legs do you have - 2, 02 or 002? They're the same number. Indeed, even the "2" part isn't really part of the number, it's only relevant in the decimal representation.

If you need padding, that suggests you're talking about the textual representation of a number... i.e. a string.

You can achieve that using string formatting options, e.g.

string text = value.ToString("0000000");

or

string text = value.ToString("D7");

How can I show three columns per row?

Try this one using Grid Layout:

_x000D_
_x000D_
.grid-container {_x000D_
  display: grid;_x000D_
  grid-template-columns: auto auto auto;_x000D_
  padding: 10px;_x000D_
}_x000D_
.grid-item {_x000D_
  background-color: rgba(255, 255, 255, 0.8);_x000D_
  border: 1px solid rgba(0, 0, 0, 0.8);_x000D_
  padding: 20px;_x000D_
  font-size: 30px;_x000D_
  text-align: center;_x000D_
}
_x000D_
<div class="grid-container">_x000D_
  <div class="grid-item">1</div>_x000D_
  <div class="grid-item">2</div>_x000D_
  <div class="grid-item">3</div>  _x000D_
  <div class="grid-item">4</div>_x000D_
  <div class="grid-item">5</div>_x000D_
  <div class="grid-item">6</div>  _x000D_
  <div class="grid-item">7</div>_x000D_
  <div class="grid-item">8</div>_x000D_
  <div class="grid-item">9</div>  _x000D_
</div>
_x000D_
_x000D_
_x000D_

How do include paths work in Visual Studio?

If you are only trying to change the include paths for a project and not for all solutions then in Visual Studio 2008 do this: Right-click on the name of the project in the Solution Navigator. From the popup menu select Properties. In the property pages dialog select Configuration Properties->C/C++/General. Click in the text box next to the "Additional Include Files" label and browse for the appropriate directory. Select OK.

What annoys me is that some of the answers to the original question asked do not apply to the version of Visual Studio that was mentioned.

How to activate "Share" button in android app?

Create a button with an id share and add the following code snippet.

share.setOnClickListener(new View.OnClickListener() {             
    @Override
    public void onClick(View v) {

        Intent sharingIntent = new Intent(android.content.Intent.ACTION_SEND);
        sharingIntent.setType("text/plain");
        String shareBody = "Your body here";
        String shareSub = "Your subject here";
        sharingIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, shareSub);
        sharingIntent.putExtra(android.content.Intent.EXTRA_TEXT, shareBody);
        startActivity(Intent.createChooser(sharingIntent, "Share using"));
    }
});

The above code snippet will open the share chooser on share button click action. However, note...The share code snippet might not output very good results using emulator. For actual results, run the code snippet on android device to get the real results.

How to use addTarget method in swift 3

The poster's second comment from September 21st is spot on. For those who may be coming to this thread later with the same problem as the poster, here is a brief explanation. The other answers are good to keep in mind, but do not address the common issue encountered by this code.

In Swift, declarations made with the let keyword are constants. Of course if you were going to add items to an array, the array can't be declared as a constant, but a segmented control should be fine, right?! Not if you reference the completed segmented control in its declaration.

Referencing the object (in this case a UISegmentedControl, but this also happens with UIButton) in its declaration when you say .addTarget and let the target be self, things crash. Why? Because self is in the midst of being defined. But we do want to define behaviour as part of the object... Declare it lazily as a variable with var. The lazy fools the compiler into thinking that self is well defined - it silences your compiler from caring at the time of declaration. Lazily declared variables don't get set until they are first called. So in this situation, lazy lets you use the notion of self without issue while you set up the object, and then when your object gets a .touchUpInside or .valueChanged or whatever your 3rd argument is in your .addTarget(), THEN it calls on the notion of self, which at that point is fully established and totally prepared to be a valid target. So it lets you be lazy in declaring your variable. In cases like these, I think they could give us a keyword like necessary, but it is generally seen as a lazy, sloppy practice and you don't want to use it all over your code, though it may have its place in this sort of situation. What it

There is no lazy let in Swift (no lazy for constants).

Here is the Apple documentation on lazy.

Here is the Apple on variables and constants. There is a little more in their Language Reference under Declarations.

How do I select between the 1st day of the current month and current day in MySQL?

I used this one

select DATE_ADD(DATE_SUB(LAST_DAY(now()), INTERVAL  1 MONTH),INTERVAL  1 day) first_day
      ,LAST_DAY(now()) last_day, date(now()) today_day

Tracking changes in Windows registry

There are a few different ways. If you want to do it yourself on the fly WMI is probably the way to go. RegistryKeyChangeEvent and its relatives are the ones to look at. There might be a way to monitor it through __InstanceCreationEvent, __InstanceDeletionEvent and __InstanceModificationEvent classes too.

http://msdn.microsoft.com/en-us/library/aa393040(VS.85).aspx

App.Config Transformation for projects which are not Web Projects in Visual Studio?

I tried several solutions and here is the simplest I personally found.
Dan pointed out in the comments that the original post belongs to Oleg Sychthanks, Oleg!

Here are the instructions:

1. Add an XML file for each configuration to the project.

Typically you will have Debug and Release configurations so name your files App.Debug.config and App.Release.config. In my project, I created a configuration for each kind of environment, so you might want to experiment with that.

2. Unload project and open .csproj file for editing

Visual Studio allows you to edit .csproj files right in the editor—you just need to unload the project first. Then right-click on it and select Edit <ProjectName>.csproj.

3. Bind App.*.config files to main App.config

Find the project file section that contains all App.config and App.*.config references. You'll notice their build actions are set to None:

<None Include="App.config" />
<None Include="App.Debug.config" />
<None Include="App.Release.config" />

First, set build action for all of them to Content.
Next, make all configuration-specific files dependant on the main App.config so Visual Studio groups them like it does designer and code-behind files.

Replace XML above with the one below:

<Content Include="App.config" />
<Content Include="App.Debug.config" >
  <DependentUpon>App.config</DependentUpon>
</Content>
<Content Include="App.Release.config" >
  <DependentUpon>App.config</DependentUpon>
</Content>

4. Activate transformations magic (only necessary for Visual Studio versions pre VS2017)

In the end of file after

<Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />

and before final

</Project>

insert the following XML:

  <UsingTask TaskName="TransformXml" AssemblyFile="$(MSBuildExtensionsPath)\Microsoft\VisualStudio\v$(VisualStudioVersion)\Web\Microsoft.Web.Publishing.Tasks.dll" />
  <Target Name="CoreCompile" Condition="exists('app.$(Configuration).config')">
    <!-- Generate transformed app config in the intermediate directory -->
    <TransformXml Source="app.config" Destination="$(IntermediateOutputPath)$(TargetFileName).config" Transform="app.$(Configuration).config" />
    <!-- Force build process to use the transformed configuration file from now on. -->
    <ItemGroup>
      <AppConfigWithTargetPath Remove="app.config" />
      <AppConfigWithTargetPath Include="$(IntermediateOutputPath)$(TargetFileName).config">
        <TargetPath>$(TargetFileName).config</TargetPath>
      </AppConfigWithTargetPath>
    </ItemGroup>
  </Target>

Now you can reload the project, build it and enjoy App.config transformations!

FYI

Make sure that your App.*.config files have the right setup like this:

<?xml version="1.0" encoding="utf-8"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
     <!--magic transformations here-->
</configuration>

python JSON object must be str, bytes or bytearray, not 'dict

import json
data = json.load(open('/Users/laxmanjeergal/Desktop/json.json'))
jtopy=json.dumps(data) #json.dumps take a dictionary as input and returns a string as output.
dict_json=json.loads(jtopy) # json.loads take a string as input and returns a dictionary as output.
print(dict_json["shipments"])

How do I get the AM/PM value from a DateTime?

Here is an easier way you can write the time format (hh:mm:ss tt) and display them separately if you wish.

string time = DateTime.Now.Hour.ToString("00") + ":" + DateTime.Now.Minute.ToString("00") + ":" + DateTime.Now.Second.ToString("00") + DateTime.Now.ToString(" tt");

or just simply:

 DateTime.Now.ToString("hh:mm:ss tt")

MySQL show current connection info

If you want to know the port number of your local host on which Mysql is running you can use this query on MySQL Command line client --

SHOW VARIABLES WHERE Variable_name = 'port';


mysql> SHOW VARIABLES WHERE Variable_name = 'port';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| port          | 3306  |
+---------------+-------+
1 row in set (0.00 sec)

It will give you the port number on which MySQL is running.


If you want to know the hostname of your Mysql you can use this query on MySQL Command line client --

SHOW VARIABLES WHERE Variable_name = 'hostname';


mysql> SHOW VARIABLES WHERE Variable_name = 'hostname';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| hostname          | Dell  |
+-------------------+-------+
1 row in set (0.00 sec)

It will give you the hostname for mysql.


If you want to know the username of your Mysql you can use this query on MySQL Command line client --

select user();   


mysql> select user();
+----------------+
| user()         |
+----------------+
| root@localhost |
+----------------+
1 row in set (0.00 sec)

It will give you the username for mysql.

Git Push ERROR: Repository not found

If you belong to a group in Github check that you have Write Access.

Eclipse: "'Periodic workspace save.' has encountered a pro?blem."

Today I faced the same issue consistently, whenever I exit the eclipse. While trying the above solution provided by TS.xy, the below steps got rid of this issue for now.

  1. Switch to new workspace and close the Eclipse.
  2. Open the Eclipse with new workspace and after that switch to the actual workspace(in which exception occurs).
  3. Actual workspace loaded with all my previous projects.
  4. Now exiting the Eclipse, does not result in that exception.

Hope that this step may work for someone.

How to save the contents of a div as a image?

Do something like this:

A <div> with ID of #imageDIV, another one with ID #download and a hidden <div> with ID #previewImage.

Include the latest version of jquery, and jspdf.debug.js from the jspdf CDN

Then add this script:

var element = $("#imageDIV"); // global variable
var getCanvas; // global variable
$('document').ready(function(){
  html2canvas(element, {
    onrendered: function (canvas) {
      $("#previewImage").append(canvas);
      getCanvas = canvas;
    }
  });
});
$("#download").on('click', function () {
  var imgageData = getCanvas.toDataURL("image/png");
  // Now browser starts downloading it instead of just showing it
  var newData = imageData.replace(/^data:image\/png/, "data:application/octet-stream");
  $("#download").attr("download", "image.png").attr("href", newData);
});

The div will be saved as a PNG on clicking the #download

How in node to split string by newline ('\n')?

I made an eol module for working with line endings in node or browsers. It has a split method like

var lines = eol.split(text)

failed to lazily initialize a collection of role

Lazy exceptions occur when you fetch an object typically containing a collection which is lazily loaded, and try to access that collection.

You can avoid this problem by

  • accessing the lazy collection within a transaction.
  • Initalizing the collection using Hibernate.initialize(obj);
  • Fetch the collection in another transaction
  • Use Fetch profiles to select lazy/non-lazy fetching runtime
  • Set fetch to non-lazy (which is generally not recommended)

Further I would recommend looking at the related links to your right where this question has been answered many times before. Also see Hibernate lazy-load application design.

How to tell which row number is clicked in a table?

This would get you the index of the clicked row, starting with one:

_x000D_
_x000D_
$('#thetable').find('tr').click( function(){_x000D_
alert('You clicked row '+ ($(this).index()+1) );_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<table id="thetable">_x000D_
   <tr>_x000D_
      <td>1</td><td>1</td><td>1</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
      <td>2</td><td>2</td><td>2</td>_x000D_
   </tr>_x000D_
   <tr>_x000D_
      <td>3</td><td>3</td><td>3</td>_x000D_
   </tr>_x000D_
</table>
_x000D_
_x000D_
_x000D_

If you want to return the number stored in that first cell of each row:

$('#thetable').find('tr').click( function(){
  var row = $(this).find('td:first').text();
  alert('You clicked ' + row);
});

How do I fix a compilation error for unhandled exception on call to Thread.sleep()?

You can get rid of the first line. You don't need import java.lang.*;

Just change your 5th line to:

public static void main(String [] args) throws Exception

m2eclipse not finding maven dependencies, artifacts not found

It sounds like your m2eclipse install is using the embedded Maven, which has its own repository (located under user home) and settings.

If you open up the Maven preferences (Window->Preferences->Maven->Installations, you can add your Maven installation by selecting Add... then browsing to the M2_HOME directory.

Preferences screenshot
(source: sonatype.com)

For more details see the m2eclipse book

Node.js Mongoose.js string to ObjectId function

var mongoose = require('mongoose');
var _id = mongoose.mongo.ObjectId("4eb6e7e7e9b7f4194e000001");

How to make --no-ri --no-rdoc the default for gem install?

# /home/{user}/.gemrc

---
:update_sources: true
:sources:
- http://gems.rubyforge.org/
- http://gems.github.com
:benchmark: false
:bulk_threshold: 1000
:backtrace: false
:verbose: true
gem: --no-ri --no-rdoc

http://webonrails.com/2008/12/03/skiping-installation-of-ri-and-rdoc-documentation-while-installing-gems/

Verify if file exists or not in C#

To test whether a file exists in .NET, you can use

System.IO.File.Exists (String)

How to run a C# console application with the console hidden

Just write

ProcessStartInfo psi= new ProcessStartInfo("cmd.exe");
......

psi.CreateNoWindow = true;

How to use if-else logic in Java 8 stream forEach

The problem by using stream().forEach(..) with a call to add or put inside the forEach (so you mutate the external myMap or myList instance) is that you can run easily into concurrency issues if someone turns the stream in parallel and the collection you are modifying is not thread safe.

One approach you can take is to first partition the entries in the original map. Once you have that, grab the corresponding list of entries and collect them in the appropriate map and list.

Map<Boolean, List<Map.Entry<K, V>>> partitions =
    animalMap.entrySet()
             .stream()
             .collect(partitioningBy(e -> e.getValue() == null));

Map<K, V> myMap = 
    partitions.get(false)
              .stream()
              .collect(toMap(Map.Entry::getKey, Map.Entry::getValue));

List<K> myList =
    partitions.get(true)
              .stream()
              .map(Map.Entry::getKey) 
              .collect(toList());

... or if you want to do it in one pass, implement a custom collector (assuming a Tuple2<E1, E2> class exists, you can create your own), e.g:

public static <K,V> Collector<Map.Entry<K, V>, ?, Tuple2<Map<K, V>, List<K>>> customCollector() {
    return Collector.of(
            () -> new Tuple2<>(new HashMap<>(), new ArrayList<>()),
            (pair, entry) -> {
                if(entry.getValue() == null) {
                    pair._2.add(entry.getKey());
                } else {
                    pair._1.put(entry.getKey(), entry.getValue());
                }
            },
            (p1, p2) -> {
                p1._1.putAll(p2._1);
                p1._2.addAll(p2._2);
                return p1;
            });
}

with its usage:

Tuple2<Map<K, V>, List<K>> pair = 
    animalMap.entrySet().parallelStream().collect(customCollector());

You can tune it more if you want, for example by providing a predicate as parameter.

Select by partial string from a pandas DataFrame

Say you have the following DataFrame:

>>> df = pd.DataFrame([['hello', 'hello world'], ['abcd', 'defg']], columns=['a','b'])
>>> df
       a            b
0  hello  hello world
1   abcd         defg

You can always use the in operator in a lambda expression to create your filter.

>>> df.apply(lambda x: x['a'] in x['b'], axis=1)
0     True
1    False
dtype: bool

The trick here is to use the axis=1 option in the apply to pass elements to the lambda function row by row, as opposed to column by column.

Representing Directory & File Structure in Markdown Syntax

If you are concerned about Unicode characters you can use ASCII to build the structures, so your example structure becomes

.
+-- _config.yml
+-- _drafts
|   +-- begin-with-the-crazy-ideas.textile
|   +-- on-simplicity-in-technology.markdown
+-- _includes
|   +-- footer.html
|   +-- header.html
+-- _layouts
|   +-- default.html
|   +-- post.html
+-- _posts
|   +-- 2007-10-29-why-every-programmer-should-play-nethack.textile
|   +-- 2009-04-26-barcamp-boston-4-roundup.textile
+-- _data
|   +-- members.yml
+-- _site
+-- index.html

Which is similar to the format tree uses if you select ANSI output.

How to load a tsv file into a Pandas DataFrame?

Try this

df = pd.read_csv("rating-data.tsv",sep='\t')
df.head()

enter image description here

You actually need to fix the sep parameter.

How do I install a custom font on an HTML site

Yes, you can use the CSS feature named @font-face. It has only been officially approved in CSS3, but been proposed and implemented in CSS2 and has been supported in IE for quite a long time.

You declare it in the CSS like this:

 @font-face { font-family: Delicious; src: url('Delicious-Roman.otf'); } 
 @font-face { font-family: Delicious; font-weight: bold; src: url('Delicious-Bold.otf');}

Then, you can just reference it like the other standard fonts:

 h3 { font-family: Delicious, sans-serif; }

So, in this case,

<html>
   <head>
    <style>
      @font-face { font-family: JuneBug; src: url('JUNEBUG.TTF'); } 
      h1 {
         font-family: JuneBug
      }
    </style>
   </head>
   <body>
      <h1>Hey, June</h1>
   </body>
</html>

And you just need to put the JUNEBUG.TFF in the same location as the html file.

I downloaded the font from the dafont.com website:

http://www.dafont.com/junebug.font

Load jQuery with Javascript and use jQuery

Using require.js you can do the same thing in a safer way. You can just define your dependency on jquery and then execute the code you want using the dependency when it is loaded without polluting the namespace:

I generally recommend this library for managing all dependencies on Javascript. It's simple and allows for an efficient optimization of resource loading. However there's some precautions you may need to take when using it with JQuery . My favourite way to deal with them is explained in this github repo and reflected by the following code sample:

<title>jQuery+RequireJS Sample Page</title>
   <script src="scripts/require.js"></script>
   <script>
   require({
       baseUrl: 'scripts',
       paths: {
           jquery: 'https://ajax.googleapis.com/ajax/libs/jquery/1.6.0/jquery.min'
       },
       priority: ['jquery']
    }, ['main']);
    </script>

Difference between / and /* in servlet mapping url pattern

Perhaps you need to know how urls are mapped too, since I suffered 404 for hours. There are two kinds of handlers handling requests. BeanNameUrlHandlerMapping and SimpleUrlHandlerMapping. When we defined a servlet-mapping, we are using SimpleUrlHandlerMapping. One thing we need to know is these two handlers share a common property called alwaysUseFullPath which defaults to false.

false here means Spring will not use the full path to mapp a url to a controller. What does it mean? It means when you define a servlet-mapping:

<servlet-mapping>
    <servlet-name>viewServlet</servlet-name>
    <url-pattern>/perfix/*</url-pattern>
</servlet-mapping>

the handler will actually use the * part to find the controller. For example, the following controller will face a 404 error when you request it using /perfix/api/feature/doSomething

@Controller()
@RequestMapping("/perfix/api/feature")
public class MyController {
    @RequestMapping(value = "/doSomething", method = RequestMethod.GET) 
    @ResponseBody
    public String doSomething(HttpServletRequest request) {
        ....
    }
}

It is a perfect match, right? But why 404. As mentioned before, default value of alwaysUseFullPath is false, which means in your request, only /api/feature/doSomething is used to find a corresponding Controller, but there is no Controller cares about that path. You need to either change your url to /perfix/perfix/api/feature/doSomething or remove perfix from MyController base @RequestingMapping.

How do I count the number of rows and columns in a file using bash?

For rows you can simply use wc -l file

-l stands for total line

for columns uou can simply use head -1 file | tr ";" "\n" | wc -l

Explanation
head -1 file
Grabbing the first line of your file, which should be the headers, and sending to it to the next cmd through the pipe
| tr ";" "\n"

tr stands for translate.
It will translate all ; characters into a newline character.
In this example ; is your delimiter.

Then it sends data to next command.

wc -l
Counts the total number of lines.