How to fetch Java version using single line command in Linux

Getting only the "major" build #:

java -version 2>&1 | head -n 1 | awk -F'["_.]' '{print $3}'

JQuery Find #ID, RemoveClass and AddClass

corrected Code:

jQuery('#testID2').addClass('test3').removeClass('test2');

JIRA JQL searching by date - is there a way of getting Today() (Date) instead of Now() (DateTime)

We're using Jira 6.2 and I use this query:

updatedDate > startOfDay(-1d) AND updatedDate < endOfDay(-1)

to return all of the issues that were updated from the previous day. You can combine with whichever queries you want to return the appropriate issues for the previous day.

Constructor of an abstract class in C#

I too want to make some shine on abstract surface All answer has covered almost all the things. Still my 2 cents

abstract classes are normal classes with A few exceptions

You any client/Consumer of that class can't create object of that class, It never means that It's constructor will never call. Its derived class can choose which constructor to call.(as depicted in some answer)
It may has abstract function.

Sum rows in data.frame or matrix

I came here hoping to find a way to get the sum across all columns in a data table and run into issues implementing the above solutions. A way to add a column with the sum across all columns uses the cbind function:

cbind(data, total = rowSums(data))

This method adds a total column to the data and avoids the alignment issue yielded when trying to sum across ALL columns using the above solutions (see the post below for a discussion of this issue).

Adding a new column to matrix error

How do I use SELECT GROUP BY in DataTable.Select(Expression)?

dt = dt.AsEnumerable().GroupBy(r => r.Field<int>("ID")).Select(g => g.First()).CopyToDataTable();

Base64 Java encode and decode a string

For Spring Users , Spring Security has a Base64 class in the org.springframework.security.crypto.codec package that can also be used for encoding and decoding of Base64. Ex.

 public static String base64Encode(String token) {
    byte[] encodedBytes = Base64.encode(token.getBytes());
    return new String(encodedBytes, Charset.forName("UTF-8"));
}


public static String base64Decode(String token) {
    byte[] decodedBytes = Base64.decode(token.getBytes());
    return new String(decodedBytes, Charset.forName("UTF-8"));
}

Make footer stick to bottom of page correctly

The simplest solution is to use min-height on the <html> tag and position the <footer> with position:absolute;

Demo: jsfiddle and SO snippet:

_x000D_

html {_x000D_
    position: relative;_x000D_
    min-height: 100%;_x000D_
}_x000D_
_x000D_
body {_x000D_
    margin: 0 0 100px;_x000D_
    /* bottom = footer height */_x000D_
    padding: 25px;_x000D_
}_x000D_
_x000D_
footer {_x000D_
    background-color: orange;_x000D_
    position: absolute;_x000D_
    left: 0;_x000D_
    bottom: 0;_x000D_
    height: 100px;_x000D_
    width: 100%;_x000D_
    overflow: hidden;_x000D_
}

_x000D_

<article>_x000D_
    <!-- or <div class="container">, etc. -->_x000D_
    <h1>James Dean CSS Sticky Footer</h1>_x000D_
    <p>Blah blah blah blah</p>_x000D_
    <p>More blah blah blah</p>_x000D_
</article>_x000D_
<footer>_x000D_
    <h1>Footer Content</h1>_x000D_
</footer>

_x000D_

Convert java.time.LocalDate into java.util.Date type

java.time has the Temporal interface which you can use to create Instant objects from most of the the time classes. Instant represents milliseconds on the timeline in the Epoch - the base reference for all other dates and times.

We need to convert the Date into a ZonedDateTime, with a Time and a Zone, to do the conversion:

LocalDate ldate = ...;
Instant instant = Instant.from(ldate.atStartOfDay(ZoneId.of("GMT")));
Date date = Date.from(instant);

How do Python functions handle the types of the parameters that you pass in?

There's one notorious exception from the duck-typing worth mentioning on this page.

When str function calls __str__ class method it subtly ?hecks its type:

>>> class A(object):
...     def __str__(self):
...         return 'a','b'
...
>>> a = A()
>>> print a.__str__()
('a', 'b')
>>> print str(a)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: __str__ returned non-string (type tuple)

As if Guido hints us which exception should a program raise if it encounters an unexpected type.

OSX El Capitan: sudo pip install OSError: [Errno: 1] Operation not permitted

TL;DR $PATH fix

Use pip install --user package_name to install a package that should include CLI executables.
Launch a python shell and import package_name
Find where lib/python/... occurs in the output and replace it all with bin
It's likely to be $HOME/Library/Python/2.7/bin

Details

Because of the new System Integrity Protection in macOS 10.11 El Capitan, you can no longer sudo pip install. We won't debate the merits of that here.

Another answer explains that you should pip install --user which is correct. But they sent you to the back alleys to figure out what to do about your $PATH so that you could get access to installed executables. Luckily, I've already solved a similar need for an unrelated question.

Here is a transcript of how I solved the problem on one of my systems. I'm including it all rather just than the $PATH that worked for me, because your system may be different from mine. This process should work for everybody.

$ pip install --user jp
Collecting jp
  Downloading jp-0.2.4.tar.gz
Installing collected packages: jp
  Running setup.py install for jp ... done
Successfully installed jp-0.2.4

$ python -c 'import jp; print jp'
<module 'jp' from '/Users/bbronosky/Library/Python/2.7/lib/python/site-packages/jp/__init__.pyc'>

$ find /Users/bbronosky/Library/Python -type f -perm -100
/Users/bbronosky/Library/Python/2.7/bin/jp

$ which jp

$ echo -e '\n''export PATH=$HOME/Library/Python/2.7/bin:$PATH' >> ~/.bashrc

$ bash # starting a new bash process for demo, but you should open a new terminal

$ which jp
/Users/bbronosky/Library/Python/2.7/bin/jp

$ jp
usage: jp <expression> <filepath>

Intellij IDEA Java classes not auto compiling on save

Please follow these steps carefully to enable it.

1) create Spring Boot project with SB V1.3 and add "Devtools" (1*) to dependencies

2) invoke Help->Find Action... and type "Registry", in the dialog search for "automake" and enable the entry "compiler.automake.allow.when.app.running", close dialog

3) enable background compilation in Settings->Build, Execution, Deployment->Compiler "Make project automatically"

4) open Spring Boot run config, you should get warning message if everything is configured correctly

5) Run your app, change your classes on-the-fly

Please report your experiences and problems as comments to this issue.

click here for more info

How do I vertical center text next to an image in html/css?

That's a fun one. If you know ahead of time the height of the container of the text, you can use line-height equal to that height, and it should center the text vertically.

What is the difference between HTTP 1.1 and HTTP 2.0?

HTTP/2 supports queries multiplexing, headers compression, priority and more intelligent packet streaming management. This results in reduced latency and accelerates content download on modern web pages.

More details here.

How to create an HTTPS server in Node.js?

You can use also archive this with the Fastify framework:

const { readFileSync } = require('fs')
const Fastify = require('fastify')

const fastify = Fastify({
  https: {
    key: readFileSync('./test/asset/server.key'),
    cert: readFileSync('./test/asset/server.cert')
  },
  logger: { level: 'debug' }
})

fastify.listen(8080)

(and run openssl req -nodes -new -x509 -keyout server.key -out server.cert to create the files if you need to write tests)

Why is my JavaScript function sometimes "not defined"?

I think your javascript code should be placed between tag,there is need of document load

ImportError: No module named Crypto.Cipher

I had the same problem on my Mac when installing with pip. I then removed pycrypto and installed it again with easy_install, like this:

pip uninstall pycrypto
easy_install pycrypto

also as Luke commented: If you have trouble running these commands, be sure to run them as admin (sudo)

Hope this helps!

EDIT: As winklerr correctly notes above, pycrypto is no longer safe. Use pycryptodome instead, it is a drop-in replacement

Regex pattern including all special characters

SInce you don't have white-space and underscore in your character class I think following regex will be better for you:

Pattern regex = Pattern.compile("[^\w\s]");

Which means match everything other than [A-Za-z0-9\s_]

Unicode version:

Pattern regex = Pattern.compile("[^\p{L}\d\s_]");

'Malformed UTF-8 characters, possibly incorrectly encoded' in Laravel

In my case I had a ucfirst on the asian letters string. This was not possible and produced a non utf8 string.

What's the difference between :: (double colon) and -> (arrow) in PHP?

Yes, I just hit my first 'PHP Parse error: syntax error, unexpected T_PAAMAYIM_NEKUDOTAYIM'. My bad, I had a $instance::method() that should have been $instance->method(). Silly me.

The odd thing is that this still works just fine on my local machine (running PHP 5.3.8) - nothing, not even a warning with error_reporting = E_ALL - but not at all on the test server, there it just explodes with a syntax error and a white screen in the browser. Since PHP logging was turned off at the test machine, and the hosting company was too busy to turn it on, it was not too obvious.

So, word of warning: apparently, some PHP installations will let you use a $instance::method(), while others don't.

If anybody can expand on why that is, please do.

Finding duplicate integers in an array and display how many times they occurred

int[] arr = { 10, 5, 10, 2, 2, 3, 4, 5, 5, 6, 7, 8, 9, 11, 12, 12 };
var result = arr.GroupBy(x => x).Select(x => new { key = x.Key, val = x.Count() });       
foreach (var item in result)
{
    if(item.val > 1)
    {                
        Console.WriteLine("Duplicate value : {0}", item.key);
        Console.WriteLine("MaxCount : {0}", item.val);
    }

}

Console.ReadLine();

Complex JSON nesting of objects and arrays

Make sure you follow the language definition for JSON. In your second example, the section:

"labs":[{
    ""
}]

Is invalid since an object must be composed of zero or more key-value pairs "a" : "b", where "b" may be any valid value. Some parsers may automatically interpret { "" } to be { "" : null }, but this is not a clearly defined case.

Also, you are using a nested array of objects [{}] quite a bit. I would only do this if:

There is no good "identifier" string for each object in the array.
There is some clear reason for having an array over a key-value for that entry.

Why Is Subtracting These Two Times (in 1927) Giving A Strange Result?

As others said, it's a time change in 1927 in Shanghai.

It was 23:54:07 in Shanghai, in the local standard time, but then after 5 minutes and 52 seconds, it turned to the next day at 00:00:00, and then local standard time changed back to 23:54:08. So, that's why the difference between the two times is 343 seconds, not 1 second, as you would have expected.

The time can also mess up in other places like the US. The US has Daylight Saving Time. When the Daylight Saving Time starts the time goes forward 1 hour. But after a while, the Daylight Saving Time ends, and it goes backward 1 hour back to the standard time zone. So sometimes when comparing times in the US the difference is about 3600 seconds not 1 second.

But there is something different about these two-time changes. The latter changes continuously and the former was just a change. It didn't change back or change again by the same amount.

It's better to use UTC unless if needed to use non-UTC time like in display.

AngularJS: Uncaught Error: [$injector:modulerr] Failed to instantiate module?

Try using No Wrap - In Head or No wrap - in body in your fiddle:

Working fiddle: http://jsfiddle.net/Q5hd6/

Explanation:

Angular begins compiling the DOM when the DOM is fully loaded. You register your code to run onLoad (onload option in fiddle) => it's too late to register your myApp module because angular begins compiling the DOM and angular sees that there is no module named myApp and throws an exception.

By using No Wrap - In Head, your code looks like this:

<head>

    <script type='text/javascript' src='//cdnjs.cloudflare.com/ajax/libs/angular.js/1.2.1/angular.js'></script>

    <script type='text/javascript'>
      //Your script.
    </script>

</head>

Your script has a chance to run before angular begins compiling the DOM and myApp module is already created when angular starts compiling the DOM.

Way to get all alphabetic chars in an array in PHP?

All good answers, in case someone is looking for an array of lower and upper case alphabets, here it is:

$alpha = array('A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z');

The tilde operator in Python

I was solving this leetcode problem and I came across this beautiful solution by a user named Zitao Wang.

The problem goes like this for each element in the given array find the product of all the remaining numbers without making use of divison and in O(n) time

The standard solution is:

Pass 1: For all elements compute product of all the elements to the left of it
Pass 2: For all elements compute product of all the elements to the right of it
        and then multiplying them for the final answer

His solution uses only one for loop by making use of. He computes the left product and right product on the fly using ~

def productExceptSelf(self, nums):
    res = [1]*len(nums)
    lprod = 1
    rprod = 1
    for i in range(len(nums)):
        res[i] *= lprod
        lprod *= nums[i]
        res[~i] *= rprod
        rprod *= nums[~i]
    return res

How to check if an option is selected?

use

 $("#mySelectBox option:selected");

to test if its a particular option myoption:

 if($("#mySelectBox option:selected").text() == myoption){
          //...
 }

How do I (or can I) SELECT DISTINCT on multiple columns?

SELECT DISTINCT a,b,c FROM t

is roughly equivalent to:

SELECT a,b,c FROM t GROUP BY a,b,c

It's a good idea to get used to the GROUP BY syntax, as it's more powerful.

For your query, I'd do it like this:

UPDATE sales
SET status='ACTIVE'
WHERE id IN
(
    SELECT id
    FROM sales S
    INNER JOIN
    (
        SELECT saleprice, saledate
        FROM sales
        GROUP BY saleprice, saledate
        HAVING COUNT(*) = 1 
    ) T
    ON S.saleprice=T.saleprice AND s.saledate=T.saledate
 )

Selenium Webdriver submit() vs click()

.Click() - Perform only click operation as like mouse click.

.Submit() - Perform Enter operation as like keyboard Enter event.

For Example. Consider a login page where it contains username and password and submit button.

On filling password if we want to login without clicking login button. we need to user .submit button on password where .click() operation does not work.[to login into application]

Brif.

driver.get("https:// anyURL"); 
driver.manage().window().maximize(); 
driver.manage().timeouts().implicitlyWait(30,TimeUnit.SECONDS); 
driver.findElement(By.id("txtUserId")).sendKeys("[email protected]"); 
WebElement text = driver.findElement(By.id("txtPassword")); text.sendKeys("password"); 
Thread.sleep(1000); 
text.click();   //This will not work - it will on perform click operation not submit operation
text.submit(); //This will perform submit operation has enter key

I keep getting this error for my simple python program: "TypeError: 'float' object cannot be interpreted as an integer"

As shown below, range only supports integers:

>>> range(15.0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: range() integer end argument expected, got float.
>>> range(15)
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
>>>

However, c/10 is a float because / always returns a float.

Before you put it in range, you need to make c/10 an integer. This can be done by putting it in int:

range(int(c/10))

or by using //, which returns an integer:

range(c//10)

What is the difference between BIT and TINYINT in MySQL?

A TINYINT is an 8-bit integer value, a BIT field can store between 1 bit, BIT(1), and 64 bits, BIT(64). For a boolean values, BIT(1) is pretty common.

Change default global installation directory for node.js modules in Windows?

trying to install global packages into C:\Program Files (x86)\nodejs\ gave me Run as Administrator issues, because npm was trying to install into
C:\Program Files (x86)\nodejs\node_modules\

to resolve this, change global install directory to C:\Users\{username}\AppData\Roaming\npm:

in C:\Users\{username}\, create .npmrc file with contents:

prefix = "C:\\Users\\{username}\\AppData\\Roaming\\npm"

reference

npm install -g package installs global packages into prefix location
npmrc userconfig takes priority and overrides
npm config ls -l was showing prefix = "C:\\Program Files (x86)\\nodejs"

environment
nodejs x86 installer into C:\Program Files (x86)\nodejs\ on Windows 7 Ultimate N 64-bit SP1
node --version : v0.10.28
npm --version : 1.4.10

jasmine: Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL

Having an argument in your it function (done in the code below) will cause Jasmine to attempt an async call.

//this block signature will trigger async behavior.
it("should work", function(done){
  //...
});

//this block signature will run synchronously
it("should work", function(){
  //...
});

It doesn't make a difference what the done argument is named, its existence is all that matters. I ran into this issue from too much copy/pasta.

The Jasmine Asynchronous Support docs note that argument (named done above) is a callback that can be called to let Jasmine know when an asynchronous function is complete. If you never call it, Jasmine will never know your test is done and will eventually timeout.

Slide right to left Android Animations

For sliding both activity (old and new) same direction:

left_in.xml

<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="300"
    android:fromXDelta="-100%"
    android:toXDelta="0%"
    android:interpolator="@android:anim/decelerate_interpolator"
     />

right_in.xml

<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="300"
    android:fromXDelta="100%"
    android:toXDelta="0%"
    android:interpolator="@android:anim/decelerate_interpolator"
     />

left_out.xml

<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="300"
    android:fromXDelta="0%"
    android:interpolator="@android:anim/decelerate_interpolator"
    android:toXDelta="-100%" />

right_out.xml

<?xml version="1.0" encoding="utf-8"?>
<translate xmlns:android="http://schemas.android.com/apk/res/android"
    android:duration="300"
    android:fromXDelta="0%"
    android:interpolator="@android:anim/decelerate_interpolator"
    android:toXDelta="100%" />

startActivity transition:

overridePendingTransition(R.anim.right_in, R.anim.left_out);

onBackPressed transition:

overridePendingTransition(R.anim.left_in, R.anim.right_out);

How to Decode Json object in laravel and apply foreach loop on that in laravel

your string is NOT a valid json to start with.

a valid json will be,

{
    "area": [
        {
            "area": "kothrud"
        },
        {
            "area": "katraj"
        }
    ]
}

if you do a json_decode, it will yield,

stdClass Object
(
    [area] => Array
        (
            [0] => stdClass Object
                (
                    [area] => kothrud
                )

            [1] => stdClass Object
                (
                    [area] => katraj
                )

        )

)

Update: to use

$string = '

{
    "area": [
        {
            "area": "kothrud"
        },
        {
            "area": "katraj"
        }
    ]
}

';
            $area = json_decode($string, true);

            foreach($area['area'] as $i => $v)
            {
                echo $v['area'].'<br/>';
            }

Output:

kothrud
katraj

Update #2:

for that true:

When TRUE, returned objects will be converted into associative arrays. for more information, click here

Linking to a specific part of a web page

That is only possible if that site has declared anchors in the page. It is done by giving a tag a name or id attribute, so look for any of those close to where you want to link to.

And then the syntax would be

<a href="page.html#anchor">text</a>

JavaScript: Difference between .forEach() and .map()

Difference between forEach() & map()

forEach() just loop through the elements. It's throws away return values and always returns undefined.The result of this method does not give us an output .

map() loop through the elements allocates memory and stores return values by iterating main array

Example:

   var numbers = [2,3,5,7];

   var forEachNum = numbers.forEach(function(number){
      return number
   })
   console.log(forEachNum)
   //output undefined

   var mapNum = numbers.map(function(number){
      return number
   })
   console.log(mapNum)
   //output [2,3,5,7]

map() is faster than forEach()

Removing duplicates from rows based on specific columns in an RDD/Spark DataFrame

I know you already accepted the other answer, but if you want to do this as a DataFrame, just use groupBy and agg. Assuming you had a DF already created (with columns named "col1", "col2", etc) you could do:

myDF.groupBy($"col1", $"col3", $"col4").agg($"col1", max($"col2"), $"col3", $"col4")

Note that in this case, I chose the Max of col2, but you could do avg, min, etc.

Selecting multiple columns in a Pandas dataframe

If you want to get one element by row index and column name, you can do it just like df['b'][0]. It is as simple as you can imagine.

Or you can use df.ix[0,'b'] - mixed usage of index and label.

Note: Since v0.20, ix has been deprecated in favour of loc / iloc.

How to split a dataframe string column into two columns?

TL;DR version:

For the simple case of:

I have a text column with a delimiter and I want two columns

The simplest solution is:

df[['A', 'B']] = df['AB'].str.split(' ', 1, expand=True)

You must use expand=True if your strings have a non-uniform number of splits and you want None to replace the missing values.

Notice how, in either case, the .tolist() method is not necessary. Neither is zip().

In detail:

Andy Hayden's solution is most excellent in demonstrating the power of the str.extract() method.

But for a simple split over a known separator (like, splitting by dashes, or splitting by whitespace), the .str.split() method is enough¹. It operates on a column (Series) of strings, and returns a column (Series) of lists:

>>> import pandas as pd
>>> df = pd.DataFrame({'AB': ['A1-B1', 'A2-B2']})
>>> df

      AB
0  A1-B1
1  A2-B2
>>> df['AB_split'] = df['AB'].str.split('-')
>>> df

      AB  AB_split
0  A1-B1  [A1, B1]
1  A2-B2  [A2, B2]

_{1: If you're unsure what the first two parameters of .str.split() do,
I recommend the docs for the plain Python version of the method.}

But how do you go from:

a column containing two-element lists

to:

two columns, each containing the respective element of the lists?

Well, we need to take a closer look at the .str attribute of a column.

It's a magical object that is used to collect methods that treat each element in a column as a string, and then apply the respective method in each element as efficient as possible:

>>> upper_lower_df = pd.DataFrame({"U": ["A", "B", "C"]})
>>> upper_lower_df

   U
0  A
1  B
2  C
>>> upper_lower_df["L"] = upper_lower_df["U"].str.lower()
>>> upper_lower_df

   U  L
0  A  a
1  B  b
2  C  c

But it also has an "indexing" interface for getting each element of a string by its index:

>>> df['AB'].str[0]

0    A
1    A
Name: AB, dtype: object

>>> df['AB'].str[1]

0    1
1    2
Name: AB, dtype: object

Of course, this indexing interface of .str doesn't really care if each element it's indexing is actually a string, as long as it can be indexed, so:

>>> df['AB'].str.split('-', 1).str[0]

0    A1
1    A2
Name: AB, dtype: object

>>> df['AB'].str.split('-', 1).str[1]

0    B1
1    B2
Name: AB, dtype: object

Then, it's a simple matter of taking advantage of the Python tuple unpacking of iterables to do

>>> df['A'], df['B'] = df['AB'].str.split('-', 1).str
>>> df

      AB  AB_split   A   B
0  A1-B1  [A1, B1]  A1  B1
1  A2-B2  [A2, B2]  A2  B2

Of course, getting a DataFrame out of splitting a column of strings is so useful that the .str.split() method can do it for you with the expand=True parameter:

>>> df['AB'].str.split('-', 1, expand=True)

    0   1
0  A1  B1
1  A2  B2

So, another way of accomplishing what we wanted is to do:

>>> df = df[['AB']]
>>> df

      AB
0  A1-B1
1  A2-B2

>>> df.join(df['AB'].str.split('-', 1, expand=True).rename(columns={0:'A', 1:'B'}))

      AB   A   B
0  A1-B1  A1  B1
1  A2-B2  A2  B2

The expand=True version, although longer, has a distinct advantage over the tuple unpacking method. Tuple unpacking doesn't deal well with splits of different lengths:

>>> df = pd.DataFrame({'AB': ['A1-B1', 'A2-B2', 'A3-B3-C3']})
>>> df
         AB
0     A1-B1
1     A2-B2
2  A3-B3-C3
>>> df['A'], df['B'], df['C'] = df['AB'].str.split('-')
Traceback (most recent call last):
  [...]    
ValueError: Length of values does not match length of index
>>>

But expand=True handles it nicely by placing None in the columns for which there aren't enough "splits":

>>> df.join(
...     df['AB'].str.split('-', expand=True).rename(
...         columns={0:'A', 1:'B', 2:'C'}
...     )
... )
         AB   A   B     C
0     A1-B1  A1  B1  None
1     A2-B2  A2  B2  None
2  A3-B3-C3  A3  B3    C3

Nested classes' scope?

I think you can simply do:

class OuterClass:
    outer_var = 1

    class InnerClass:
        pass
    InnerClass.inner_var = outer_var

The problem you encountered is due to this:

A block is a piece of Python program text that is executed as a unit. The following are blocks: a module, a function body, and a class definition.
(...)
A scope defines the visibility of a name within a block.
(...)
The scope of names defined in a class block is limited to the class block; it does not extend to the code blocks of methods – this includes generator expressions since they are implemented using a function scope. This means that the following will fail:
   class A:  

       a = 42  

       b = list(a + i for i in range(10))
http://docs.python.org/reference/executionmodel.html#naming-and-binding

The above means:
a function body is a code block and a method is a function, then names defined out of the function body present in a class definition do not extend to the function body.

Paraphrasing this for your case:
a class definition is a code block, then names defined out of the inner class definition present in an outer class definition do not extend to the inner class definition.

Equals(=) vs. LIKE

For this example we take it for granted that varcharcol doesn't contain '' and have no empty cell against this column

select * from some_table where varcharCol = ''
select * from some_table where varcharCol like ''

The first one results in 0 row output while the second one shows the whole list. = is strictly-match case while like acts like a filter. if filter has no criteria, every data is valid.

like - by the virtue of its purpose works a little slower and is intended for use with varchar and similar data.

database attached is read only

Another Way which worked for me is:

After dettaching before you attach

-> go to the .mdf file -> right click & select properties on the file -> security tab -> Check Group or usernames:

for your name\account (optional) and for "NT SERVICE\MSSQLSERVER"(NB)

List item

-> if not there than click on edit button -> click on add button

  and enter\search NT SERVICE\MSSQLSERVER

-> click on OK -> give full rights -> apply then ok

then ok again do this for .ldf file too.

then attach

A table name as a variable

You can't use a table name for a variable. You'd have to do this instead:

DECLARE @sqlCommand varchar(1000)
SET @sqlCommand = 'SELECT * from yourtable'
EXEC (@sqlCommand)

anchor jumping by using javascript

Because when you do

window.location.href = "#"+anchor;

You load a new page, you can do:

<a href="#" onclick="jumpTo('one');">One</a>
<a href="#" id="one"></a>

<script>

    function getPosition(element){
        var e = document.getElementById(element);
        var left = 0;
        var top = 0;

        do{
            left += e.offsetLeft;
            top += e.offsetTop;
        }while(e = e.offsetParent);

        return [left, top];
    }

    function jumpTo(id){    
        window.scrollTo(getPosition(id));
    }

</script>

How to get the selected date value while using Bootstrap Datepicker?

Try this using HTML like here:

var myDate = window.document.getElementById("startdate").value;

How long to brute force a salted SHA-512 hash? (salt provided)

In your case, breaking the hash algorithm is equivalent to finding a collision in the hash algorithm. That means you don't need to find the password itself (which would be a preimage attack), you just need to find an output of the hash function that is equal to the hash of a valid password (thus "collision"). Finding a collision using a birthday attack takes O(2^(n/2)) time, where n is the output length of the hash function in bits.

SHA-2 has an output size of 512 bits, so finding a collision would take O(2^256) time. Given there are no clever attacks on the algorithm itself (currently none are known for the SHA-2 hash family) this is what it takes to break the algorithm.

To get a feeling for what 2^256 actually means: currently it is believed that the number of atoms in the (entire!!!) universe is roughly 10^80 which is roughly 2^266. Assuming 32 byte input (which is reasonable for your case - 20 bytes salt + 12 bytes password) my machine takes ~0,22s (~2^-2s) for 65536 (=2^16) computations. So 2^256 computations would be done in 2^240 * 2^16 computations which would take

2^240 * 2^-2 = 2^238 ~ 10^72s ~ 3,17 * 10^64 years

Even calling this millions of years is ridiculous. And it doesn't get much better with the fastest hardware on the planet computing thousands of hashes in parallel. No human technology will be able to crunch this number into something acceptable.

So forget brute-forcing SHA-256 here. Your next question was about dictionary words. To retrieve such weak passwords rainbow tables were used traditionally. A rainbow table is generally just a table of precomputed hash values, the idea is if you were able to precompute and store every possible hash along with its input, then it would take you O(1) to look up a given hash and retrieve a valid preimage for it. Of course this is not possible in practice since there's no storage device that could store such enormous amounts of data. This dilemma is known as memory-time tradeoff. As you are only able to store so many values typical rainbow tables include some form of hash chaining with intermediary reduction functions (this is explained in detail in the Wikipedia article) to save on space by giving up a bit of savings in time.

Salts were a countermeasure to make such rainbow tables infeasible. To discourage attackers from precomputing a table for a specific salt it is recommended to apply per-user salt values. However, since users do not use secure, completely random passwords, it is still surprising how successful you can get if the salt is known and you just iterate over a large dictionary of common passwords in a simple trial and error scheme. The relationship between natural language and randomness is expressed as entropy. Typical password choices are generally of low entropy, whereas completely random values would contain a maximum of entropy.

The low entropy of typical passwords makes it possible that there is a relatively high chance of one of your users using a password from a relatively small database of common passwords. If you google for them, you will end up finding torrent links for such password databases, often in the gigabyte size category. Being successful with such a tool is usually in the range of minutes to days if the attacker is not restricted in any way.

That's why generally hashing and salting alone is not enough, you need to install other safety mechanisms as well. You should use an artificially slowed down entropy-enducing method such as PBKDF2 described in PKCS#5 and you should enforce a waiting period for a given user before they may retry entering their password. A good scheme is to start with 0.5s and then doubling that time for each failed attempt. In most cases users don't notice this and don't fail much more often than three times on average. But it will significantly slow down any malicious outsider trying to attack your application.

How to get script of SQL Server data?

I know this has been answered already, but I am here to offer a word of warning. We recently received a database from a client that has a cyclical foreign key reference. The SQL Server script generator refuses to generate the data for databases with cyclical references.

Hexadecimal value 0x00 is a invalid character

In my case, it took some digging, but found it.

My Context

I'm looking at exception/error logs from the website using Elmah. Elmah returns the state of the server at the of time the exception, in the form of a large XML document. For our reporting engine I pretty-print the XML with XmlWriter.

During a website attack, I noticed that some xmls weren't parsing and was receiving this '.', hexadecimal value 0x00, is an invalid character. exception.

NON-RESOLUTION: I converted the document to a byte[] and sanitized it of 0x00, but it found none.

When I scanned the xml document, I found the following:

...
<form>
...
<item name="SomeField">
   <value
     string="C:\boot.ini&#x0;.htm" />
 </item>
...

There was the nul byte encoded as an html entity  !!!

RESOLUTION: To fix the encoding, I replaced the  value before loading it into my XmlDocument, because loading it will create the nul byte and it will be difficult to sanitize it from the object. Here's my entire process:

XmlDocument xml = new XmlDocument();
details.Xml = details.Xml.Replace("&#x0;", "[0x00]");  // in my case I want to see it, otherwise just replace with ""
xml.LoadXml(details.Xml);

string formattedXml = null;

// I have this in a helper function, but for this example I have put it in-line
StringBuilder sb = new StringBuilder();
XmlWriterSettings settings = new XmlWriterSettings {
    OmitXmlDeclaration = true,
    Indent = true,
    IndentChars = "\t",
    NewLineHandling = NewLineHandling.None,
};
using (XmlWriter writer = XmlWriter.Create(sb, settings)) {
    xml.Save(writer);
    formattedXml = sb.ToString();
}

LESSON LEARNED: sanitize for illegal bytes using the associated html entity, if your incoming data is html encoded on entry.

How do I remove a MySQL database?

From the MySQL prompt:

mysql> drop database <db_name>;

Passing multiple argument through CommandArgument of Button in Asp.net

You can pass semicolon separated values as command argument and then split the string and use it.

<asp:TemplateField ShowHeader="false">
    <ItemTemplate>
       <asp:LinkButton ID="lnkCustomize" Text="Customize"  CommandName="Customize"  CommandArgument='<%#Eval("IdTemplate") + ";" +Eval("EntityId")%>'  runat="server"> 
       </asp:LinkButton>   
    </ItemTemplate>   
</asp:TemplateField>

at server side

protected void gridview_RowCommand(object sender, GridViewCommandEventArgs e)
{
      string[] arg = new string[2];
      arg = e.CommandArgument.ToString().Split(';');
      Session["IdTemplate"] = arg[0];
      Session["IdEntity"] = arg[1];
      Response.Redirect("Samplepage.aspx");
}

Hope it helps!!!!

PHP: if !empty & empty

if(!empty($youtube) && empty($link)) {

}
else if(empty($youtube) && !empty($link)) {

}
else if(empty($youtube) && empty($link)) {
}

How to compare two dates in php

<?php
       $expiry_date = "2017-12-31 00:00:00"
       $today = date('d-m-Y',time()); 
       $exp = date('d-m-Y',strtotime($expiry_date));
       $expDate =  date_create($exp);
       $todayDate = date_create($today);
       $diff =  date_diff($todayDate, $expDate);
       if($diff->format("%R%a")>0){
             echo "active";
       }else{
           echo "inactive";
       }
       echo "Remaining Days ".$diff->format("%R%a days");
?>

How to make canvas responsive

<div class="outer">
 <canvas id="canvas"></canvas>
</div>

.outer {
 position: relative;
 width: 100%;
 padding-bottom: 100%;
}

#canvas {
 position: absolute;
 width: 100%;
 height: 100%;
}

Sniff HTTP packets for GET and POST requests from an application

post in http
Put http.request.method == "POST" in the display filter of wireshark to only show POST requests. Click on the packet

Hide Utility Class Constructor : Utility classes should not have a public or default constructor

public class LmsEmpWfhUtils {    
    private LmsEmpWfhUtils() 
    { 
    // prevents access default paramater-less constructor
    }
}

This prevents the default parameter-less constructor from being used elsewhere in your code.

Is it possible to use 'else' in a list comprehension?

The syntax a if b else c is a ternary operator in Python that evaluates to a if the condition b is true - otherwise, it evaluates to c. It can be used in comprehension statements:

>>> [a if a else 2 for a in [0,1,0,3]]
[2, 1, 2, 3]

So for your example,

table = ''.join(chr(index) if index in ords_to_keep else replace_with
                for index in xrange(15))

How to change fontFamily of TextView in Android

Starting from Android-Studio 3.0 its very easy to change font family

Using support library 26, it will work on devices running Android API version 16 and higher

Create a folder font under res directory .Download the font which ever you want and paste it inside font folder. The structure should be some thing like below

Note: As of Android Support Library 26.0, you must declare both sets of attributes ( android: and app: ) to ensure your fonts load on devices running Api 26 or lower.

Now you can change font in layout using

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:fontFamily="@font/dancing_script"
app:fontFamily="@font/dancing_script"/>

To change Programatically

 Typeface typeface = getResources().getFont(R.font.myfont);
   //or to support all versions use
Typeface typeface = ResourcesCompat.getFont(context, R.font.myfont);
 textView.setTypeface(typeface);

To change font using styles.xml create a style

 <style name="Regular">
        <item name="android:fontFamily">@font/dancing_script</item>
        <item name="fontFamily">@font/dancing_script</item>
        <item name="android:textStyle">normal</item>
 </style>

and apply this style to TextView

  <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    style="@style/Regular"/>

you can also Create your own font family

- Right-click the font folder and go to New > Font resource file. The New Resource File window appears.

- Enter the file name, and then click OK. The new font resource XML opens in the editor.

Write your own font family here , for example

<font-family xmlns:android="http://schemas.android.com/apk/res/android">
    <font
        android:fontStyle="normal"
        android:fontWeight="400"
        android:font="@font/lobster_regular" />
    <font
        android:fontStyle="italic"
        android:fontWeight="400"
        android:font="@font/lobster_italic" />
</font-family>

this is simply a mapping of a specific fontStyle and fontWeight to the font resource which will be used to render that specific variant. Valid values for fontStyle are normal or italic; and fontWeight conforms to the CSS font-weight specification

1. To change fontfamily in layout you can write

 <TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:fontFamily="@font/lobster"/>

2. To Change Programmatically

 Typeface typeface = getResources().getFont(R.font.lobster);
   //or to support all versions use
Typeface typeface = ResourcesCompat.getFont(context, R.font.lobster);
 textView.setTypeface(typeface);

To change font of entire App Add these two lines in AppTheme

 <style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
     <item name="android:fontFamily">@font/your_font</item>
     <item name="fontFamily">@font/your_font</item>
  </style>

See the Documentation , Android Custom Fonts Tutorial For more info

How to rename a file using Python

Use os.rename:

import os

os.rename('a.txt', 'b.kml')

Angular 2 execute script after template render

I've used this method (reported here )

export class AppComponent {

  constructor() {
    if(document.getElementById("testScript"))
      document.getElementById("testScript").remove();
    var testScript = document.createElement("script");
    testScript.setAttribute("id", "testScript");
    testScript.setAttribute("src", "assets/js/test.js");
    document.body.appendChild(testScript);
  }
}

it worked for me since I wanted to execute a javascript file AFTER THE COMPONENT RENDERED.

Asp.net Validation of viewstate MAC failed

Validation of viewstate MAC failed. If this application is hosted by a web farm or cluster, ensure that <machineKey> configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

Answer :

_x000D_

<machineKey  decryptionKey="2CC8E5C3B1812451A707FBAAAEAC9052E05AE1B858993660" validation="HMACSHA256" decryption="AES" validationKey="CB8860CE588A62A2CF9B0B2F48D2C8C31A6A40F0517268CEBCA431A3177B08FC53D818B82DEDCF015A71A0C4B817EA8FDCA2B3BDD091D89F2EDDFB3C06C0CB32" />

_x000D_

Understanding the difference between Object.create() and new SomeFunction()

This:

var foo = new Foo();

and

var foo = Object.create(Foo.prototype);

are quite similar. One important difference is that new Foo actually runs constructor code, whereas Object.create will not execute code such as

function Foo() {
    alert("This constructor does not run with Object.create");
}

Note that if you use the two-parameter version of Object.create() then you can do much more powerful things.

Detect and exclude outliers in Pandas data frame

a full example with data and 2 groups follows:

Imports:

from StringIO import StringIO
import pandas as pd
#pandas config
pd.set_option('display.max_rows', 20)

Data example with 2 groups: G1:Group 1. G2: Group 2:

TESTDATA = StringIO("""G1;G2;Value
1;A;1.6
1;A;5.1
1;A;7.1
1;A;8.1

1;B;21.1
1;B;22.1
1;B;24.1
1;B;30.6

2;A;40.6
2;A;51.1
2;A;52.1
2;A;60.6

2;B;80.1
2;B;70.6
2;B;90.6
2;B;85.1
""")

Read text data to pandas dataframe:

df = pd.read_csv(TESTDATA, sep=";")

Define the outliers using standard deviations

stds = 1.0
outliers = df[['G1', 'G2', 'Value']].groupby(['G1','G2']).transform(
           lambda group: (group - group.mean()).abs().div(group.std())) > stds

Define filtered data values and the outliers:

dfv = df[outliers.Value == False]
dfo = df[outliers.Value == True]

Print the result:

print '\n'*5, 'All values with decimal 1 are non-outliers. In the other hand, all values with 6 in the decimal are.'
print '\nDef DATA:\n%s\n\nFiltred Values with %s stds:\n%s\n\nOutliers:\n%s' %(df, stds, dfv, dfo)

"Could not find a version that satisfies the requirement opencv-python"

I faced the same issue but the mistake which I was making was pip install python-opencv where I should have used pip install opencv-python. Hope this helps to anyone. It took me few hours to find.

Django Rest Framework -- no module named rest_framework

If you are working with PyCharm, I found that restarting the program and closing all prompts after adding 'rest_framework' to my INSTALLED_APPS worked for me.

How to get ALL child controls of a Windows Forms form of a specific type (Button/Textbox)?

Using reflection:

// Return a list with all the private fields with the same type
List<T> GetAllControlsWithTypeFromControl<T>(Control parentControl)
{
    List<T> retValue = new List<T>();
    System.Reflection.FieldInfo[] fields = parentControl.GetType().GetFields(System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance);
    foreach (System.Reflection.FieldInfo field in fields)
    {
      if (field.FieldType == typeof(T))
        retValue.Add((T)field.GetValue(parentControl));
    }
}

List<TextBox> ctrls = GetAllControlsWithTypeFromControl<TextBox>(this);

build failed with: ld: duplicate symbol _OBJC_CLASS_$_Algebra5FirstViewController

I got this same issue when working with Bolts.framework. It turns out that when Bolts gets corrupted, no amount of re-importing will fix the issue. I had to go back to the original download file and reimport it completely from scratch. This fixed it right away. It was such a weird issue that it took me forever to figure it out... hopefully this tip will spare some of you from the same frustrations :)

Is it possible to assign numeric value to an enum in Java?

Extending Bhesh Gurung's answer for assigning values, you can add explicit method to set value

   public ExitCode setValue( int value){
      //  A(104), B(203);
      switch(value){
        case 104: return ExitCode.A;
        case 203: return ExitCode.B;
        default:
                   return ExitCode.Unknown //Keep an default or error enum handy
      }
   }

From calling application

int i = 104; 
ExitCode serverExitCode = ExitCode.setValue(i);

//You've valid enum from now

[Unable to comment to his answer, hence posting it separately]

How to auto import the necessary classes in Android Studio with shortcut?

You can also use Eclipse's keyboard shortcuts: just go on preferences > keymap and choose Eclipse from the drop-down menu. And all your Eclipse shortcuts will be used in here.

nodejs mysql Error: Connection lost The server closed the connection

I do not recall my original use case for this mechanism. Nowadays, I cannot think of any valid use case.

Your client should be able to detect when the connection is lost and allow you to re-create the connection. If it important that part of program logic is executed using the same connection, then use transactions.

tl;dr; Do not use this method.

A pragmatic solution is to force MySQL to keep the connection alive:

setInterval(function () {
    db.query('SELECT 1');
}, 5000);

I prefer this solution to connection pool and handling disconnect because it does not require to structure your code in a way thats aware of connection presence. Making a query every 5 seconds ensures that the connection will remain alive and PROTOCOL_CONNECTION_LOST does not occur.

Furthermore, this method ensures that you are keeping the same connection alive, as opposed to re-connecting. This is important. Consider what would happen if your script relied on LAST_INSERT_ID() and mysql connection have been reset without you being aware about it?

However, this only ensures that connection time out (wait_timeout and interactive_timeout) does not occur. It will fail, as expected, in all others scenarios. Therefore, make sure to handle other errors.

Detect application heap size in Android

Here's how you do it:

Getting the max heap size that the app can use:

Runtime runtime = Runtime.getRuntime();
long maxMemory=runtime.maxMemory();

Getting how much of the heap your app currently uses:

long usedMemory=runtime.totalMemory() - runtime.freeMemory();

Getting how much of the heap your app can now use (available memory) :

long availableMemory=maxMemory-usedMemory;

And, to format each of them nicely, you can use:

String formattedMemorySize=Formatter.formatShortFileSize(context,memorySize);

Regular expression for exact match of a string

In malfaux's answer '^' and '$' has been used to detect the beginning and the end of the text.
These are usually used to detect the beginning and the end of a line.
However this may be the correct way in this case.
But if you wish to match an exact word the more elegant way is to use '\b'. In this case following pattern will match the exact phrase'123456'.

/\b123456\b/

Using Thymeleaf when the value is null

Also worth to look at documentation for #objects build-in helper: https://www.thymeleaf.org/doc/tutorials/2.1/usingthymeleaf.html#objects

There is useful: ${#objects.nullSafe(obj, default)}

Fixing npm path in Windows 8 and 10

Edit the System environment variables, and enter following path:

C:\Program Files\nodejs\node.exe;

C:\Users\{yourName}\AppData\Roaming\npm

<div style display="none" > inside a table not working

Semantically what you are trying is invalid html, table element cannot have a div element as a direct child. What you can do is, get your div element inside a td element and than try to hide it

Difference between "while" loop and "do while" loop

While:

entry control loop
condition is checked before loop execution
never execute loop if condition is false
there is no semicolon at the end of while statement

Do-while:

exit control loop
condition is checked at the end of loop
executes false condition at least once since condition is checked later
there is semicolon at the end of while statement.

Check Postgres access for a user

For all users on a specific database, do the following:

# psql
\c your_database
select grantee, table_catalog, privilege_type, table_schema, table_name from information_schema.table_privileges order by grantee, table_schema, table_name;

add onclick function to a submit button

if you need to do something before submitting data, you could use form's onsubmit.

<form method=post onsubmit="return doSomething()">
  <input type=text name=text1>
  <input type=submit>
</form>

Android: How do I prevent the soft keyboard from pushing my view up?

There are two ways of solving this problem. Go to the AndroidManifist.xml, and in the name of your activity, add this line

   android:windowSoftInputMode="adjustPan"

As in the below code, I have added to the Register Activity.

 <activity android:name=".Register"
            android:windowSoftInputMode="adjustPan">

In the second way, go to your activity, and in your onCreate method, add this code.

getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN);

Detect If Browser Tab Has Focus

I would do it this way (Reference http://www.w3.org/TR/page-visibility/):

    window.onload = function() {

        // check the visiblility of the page
        var hidden, visibilityState, visibilityChange;

        if (typeof document.hidden !== "undefined") {
            hidden = "hidden", visibilityChange = "visibilitychange", visibilityState = "visibilityState";
        }
        else if (typeof document.mozHidden !== "undefined") {
            hidden = "mozHidden", visibilityChange = "mozvisibilitychange", visibilityState = "mozVisibilityState";
        }
        else if (typeof document.msHidden !== "undefined") {
            hidden = "msHidden", visibilityChange = "msvisibilitychange", visibilityState = "msVisibilityState";
        }
        else if (typeof document.webkitHidden !== "undefined") {
            hidden = "webkitHidden", visibilityChange = "webkitvisibilitychange", visibilityState = "webkitVisibilityState";
        }


        if (typeof document.addEventListener === "undefined" || typeof hidden === "undefined") {
            // not supported
        }
        else {
            document.addEventListener(visibilityChange, function() {
                console.log("hidden: " + document[hidden]);
                console.log(document[visibilityState]);

                switch (document[visibilityState]) {
                case "visible":
                    // visible
                    break;
                case "hidden":
                    // hidden
                    break;
                }
            }, false);
        }

        if (document[visibilityState] === "visible") {
            // visible
        }

    };

How to get current local date and time in Kotlin

You can get current year, month, day etc from a calendar instance

val c = Calendar.getInstance()

val year = c.get(Calendar.YEAR)
val month = c.get(Calendar.MONTH)
val day = c.get(Calendar.DAY_OF_MONTH)

val hour = c.get(Calendar.HOUR_OF_DAY)
val minute = c.get(Calendar.MINUTE)

If you need it as a LocalDateTime, simply create it by using the parameters you got above

val myLdt = LocalDateTime.of(year, month, day, ... )

"This operation requires IIS integrated pipeline mode."

Press F4 in your Project for the property window. Then change the pipeline mode

How to display PDF file in HTML?

I've had something similar before and used normally tags

<a href="path_of_your_pdf/your_pdf_file.pdf" tabindex="-1"><strong>click here</strong></a>

but it's interesting to find out some other ways as above!

In a Git repository, how to properly rename a directory?

For case sensitive renaming, git mv somefolder someFolder has worked for me before but didn't today for some reason. So as a workaround I created a new folder temp, moved all the contents of somefolder into temp, deleted somefolder, committed the temp, then created someFolder, moved all the contents of temp into someFolder, deleted temp, committed and pushed someFolder and it worked! Shows up as someFolder in git.

How do I consume the JSON POST data in an Express application

_x000D_

const express = require('express');_x000D_
let app = express();_x000D_
app.use(express.json());

_x000D_

This app.use(express.json) will now let you read the incoming post JSON object

How can I make an image transparent on Android?

The method setAlpha(int) from the type ImageView is deprecated.

Instead of

image.setImageAlpha(127);
//value: [0-255]. Where 0 is fully transparent and 255 is fully opaque.

How to get Javascript Select box's selected text

Just use

$('#SelectBoxId option:selected').text(); For Getting text as listed

$('#SelectBoxId').val(); For Getting selected Index value

What is the difference between char s[] and char *s?

This declaration:

char s[] = "hello";

Creates one object - a char array of size 6, called s, initialised with the values 'h', 'e', 'l', 'l', 'o', '\0'. Where this array is allocated in memory, and how long it lives for, depends on where the declaration appears. If the declaration is within a function, it will live until the end of the block that it is declared in, and almost certainly be allocated on the stack; if it's outside a function, it will probably be stored within an "initialised data segment" that is loaded from the executable file into writeable memory when the program is run.

On the other hand, this declaration:

char *s ="hello";

Creates two objects:

a read-only array of 6 chars containing the values 'h', 'e', 'l', 'l', 'o', '\0', which has no name and has static storage duration (meaning that it lives for the entire life of the program); and
a variable of type pointer-to-char, called s, which is initialised with the location of the first character in that unnamed, read-only array.

The unnamed read-only array is typically located in the "text" segment of the program, which means it is loaded from disk into read-only memory, along with the code itself. The location of the s pointer variable in memory depends on where the declaration appears (just like in the first example).

Declaring multiple variables in JavaScript

Although both are valid, using the second discourages inexperienced developers from placing var statements all over the place and causing hoisting issues. If there is only one var per function, at the top of the function, then it is easier to debug the code as a whole. This can mean that the lines where the variables are declared are not as explicit as some may like.

I feel that trade-off is worth it, if it means weaning a developer off of dropping 'var' anywhere they feel like.

People may complain about JSLint, I do as well, but a lot of it is geared not toward fixing issues with the language, but in correcting bad habits of the coders and therefore preventing problems in the code they write. Therefore:

"In languages with block scope, it is usually recommended that variables be declared at the site of first use. But because JavaScript does not have block scope, it is wiser to declare all of a function's variables at the top of the function. It is recommended that a single var statement be used per function." - http://www.jslint.com/lint.html#scope

Your branch is ahead of 'origin/master' by 3 commits

If your git says you are commit ahead then just First,

git push origin

To make sure u have pushed all ur latest work in repo

Then,

git reset --hard origin/master

To reset and match up with the repo

Get all inherited classes of an abstract class

Assuming they are all defined in the same assembly, you can do:

IEnumerable<AbstractDataExport> exporters = typeof(AbstractDataExport)
    .Assembly.GetTypes()
    .Where(t => t.IsSubclassOf(typeof(AbstractDataExport)) && !t.IsAbstract)
    .Select(t => (AbstractDataExport)Activator.CreateInstance(t));

How to set border's thickness in percentages?

Border doesn't support percentage... but it's still possible...

As others have pointed to CSS specification, percentages aren't supported on borders:

'border-top-width',
'border-right-width',
'border-bottom-width',
'border-left-width'
  Value:          <border-width> | inherit
  Initial:        medium
  Applies to:     all elements
  Inherited:      no
  Percentages:    N/A
  Media:          visual
  Computed value: absolute length; '0' if the border style is 'none' or 'hidden'

As you can see it says Percentages: N/A.

Non-scripted solution

You can simulate your percentage borders with a wrapper element where you would:

set wrapper element's background-color to your desired border colour
set wrapper element's padding in percentages (because they're supported)
set your elements background-color to white (or whatever it needs to be)

This would somehow simulate your percentage borders. Here's an example of an element with 25% width side borders that uses this technique.

HTML used in the example

_x000D_

.faux-borders {_x000D_
    background-color: #f00;_x000D_
    padding: 1px 25%; /* set padding to simulate border */_x000D_
}_x000D_
.content {_x000D_
    background-color: #fff;_x000D_
}

_x000D_

<div class="faux-borders">_x000D_
    <div class="content">_x000D_
        This is the element to have percentage borders._x000D_
    </div>_x000D_
</div>

_x000D_

Issue: You have to be aware that this will be much more complicated when your element has some complex background applied to it... Especially if that background is inherited from ancestor DOM hierarchy. But if your UI is simple enough, you can do it this way.

Scripted solution

@BoltClock mentioned scripted solution where you can programmaticaly calculate border width according to element size.

This is such an example with extremely simple script using jQuery.

_x000D_

var el = $(".content");_x000D_
var w = el.width() / 4 | 0; // calculate & trim decimals_x000D_
el.css("border-width", "1px " + w + "px");

_x000D_

.content { border: 1px solid #f00; }

_x000D_

<div class="content">_x000D_
    This is the element to have percentage borders._x000D_
</div>

_x000D_

But you have to be aware that you will have to adjust border width every time your container size changes (i.e. browser window resize). My first workaround with wrapper element seems much simpler because it will automatically adjust width in these situations.

The positive side of scripted solution is that it doesn't suffer from background problems mentioned in my previous non-scripted solution.

How to install crontab on Centos

As seen in Install crontab on CentOS, the crontab package in CentOS is vixie-cron. Hence, do install it with:

yum install vixie-cron

And then start it with:

service crond start

To make it persistent, so that it starts on boot, use:

chkconfig crond on

On CentOS 7 you need to use cronie:

yum install cronie

On CentOS 6 you can install vixie-cron, but the real package is cronie:

yum install vixie-cron

and

yum install cronie

In both cases you get the same output:

.../...
==================================================================
 Package         Arch       Version         Repository      Size
==================================================================
Installing:
 cronie          x86_64     1.4.4-12.el6    base             73 k
Installing for dependencies:
 cronie-anacron  x86_64     1.4.4-12.el6    base             30 k
 crontabs        noarch     1.10-33.el6     base             10 k
 exim            x86_64     4.72-6.el6      epel            1.2 M

Transaction Summary
==================================================================
Install       4 Package(s)

Returning binary file from controller in ASP.NET Web API

For anyone having the problem of the API being called more than once while downloading a fairly large file using the method in the accepted answer, please set response buffering to true System.Web.HttpContext.Current.Response.Buffer = true;

This makes sure that the entire binary content is buffered on the server side before it is sent to the client. Otherwise you will see multiple request being sent to the controller and if you do not handle it properly, the file will become corrupt.

Can anybody tell me details about hs_err_pid.log file generated when Tomcat crashes?

A very very good document regarding this topic is Troubleshooting Guide for Java from (originally) Sun. See the chapter "Troubleshooting System Crashes" for information about hs_err_pid* Files.

See Appendix C - Fatal Error Log

Per the guide, by default the file will be created in the working directory of the process if possible, or in the system temporary directory otherwise. A specific location can be chosen by passing in the -XX:ErrorFile product flag. It says:

If the -XX:ErrorFile= file flag is not specified, the system attempts to create the file in the working directory of the process. In the event that the file cannot be created in the working directory (insufficient space, permission problem, or other issue), the file is created in the temporary directory for the operating system.

java.lang.ClassNotFoundException: org.apache.log4j.Level

In my environment, I just added the two files to class path. And is work fine.

slf4j-jdk14-1.7.25.jar
slf4j-api-1.7.25.jar

subquery in FROM must have an alias

In the case of nested tables, some DBMS require to use an alias like MySQL and Oracle but others do not have such a strict requirement, but still allow to add them to substitute the result of the inner query.

Forward host port to docker container

I had a similar problem accessing a LDAP-Server from a docker container. I set a fixed IP for the container and added a firewall rule.

docker-compose.yml:

version: '2'
services:
  containerName:
    image: dockerImageName:latest
    extra_hosts:
      - "dockerhost:192.168.50.1"
    networks:
      my_net:
        ipv4_address: 192.168.50.2
networks:
  my_net:
    ipam:
      config:
      - subnet: 192.168.50.0/24

iptables rule:

iptables -A INPUT -j ACCEPT -p tcp -s 192.168.50.2 -d $192.168.50.1 --dport portnumberOnHost

Inside the container access dockerhost:portnumberOnHost

Is the LIKE operator case-sensitive with MSSQL Server?

You can change from the property of every item.

Javascript : get <img> src and set as variable?

If you don't have an id on the image but have a parent div this is also a technique you can use.

<div id="myDiv"><img src="http://www.example.com/image.png"></div>

var myVar = document.querySelectorAll('#myDiv img')[0].src

ReactJS Two components communicating

This is the way I handled this.
Let's say you have a <select> for Month and a <select> for Day. The number of days depends on the selected month.

Both lists are owned by a third object, the left panel. Both <select> are also children of the leftPanel <div>
It's a game with the callbacks and the handlers in the LeftPanel component.

To test it, just copy the code into two separated files and run the index.html. Then select a month and see how the number of days changes.

dates.js

    /** @jsx React.DOM */


    var monthsLength = [0,31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
    var MONTHS_ARR = ["Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"];

    var DayNumber = React.createClass({
        render: function() {
            return (
                <option value={this.props.dayNum}>{this.props.dayNum}</option>
            );
        }
    });

    var DaysList = React.createClass({
        getInitialState: function() {
            return {numOfDays: 30};
        },
        handleMonthUpdate: function(newMonthix) {
            this.state.numOfDays = monthsLength[newMonthix];
            console.log("Setting days to " + monthsLength[newMonthix] + " month = " + newMonthix);

            this.forceUpdate();
        },
        handleDaySelection: function(evt) {
            this.props.dateHandler(evt.target.value);
        },
        componentDidMount: function() {
            this.props.readyCallback(this.handleMonthUpdate)
        },
        render: function() {
            var dayNodes = [];
            for (i = 1; i <= this.state.numOfDays; i++) {
                dayNodes = dayNodes.concat([<DayNumber dayNum={i} />]);
            }
            return (
                <select id={this.props.id} onChange = {this.handleDaySelection}>
                    <option value="" disabled defaultValue>Day</option>
                        {dayNodes}
                </select>
                );
        }
    });

    var Month = React.createClass({
        render: function() {
            return (
                <option value={this.props.monthIx}>{this.props.month}</option>
            );
        }
    });

    var MonthsList = React.createClass({
        handleUpdate: function(evt) {
            console.log("Local handler:" + this.props.id + " VAL= " + evt.target.value);
            this.props.dateHandler(evt.target.value);

            return false;
        },
        render: function() {
            var monthIx = 0;

            var monthNodes = this.props.data.map(function (month) {
                monthIx++;
                return (
                    <Month month={month} monthIx={monthIx} />
                    );
            });

            return (
                <select id = {this.props.id} onChange = {this.handleUpdate}>
                    <option value="" disabled defaultValue>Month</option>
                        {monthNodes}
                </select>
                );
        }
    });

    var LeftPanel = React.createClass({
        dayRefresh: function(newMonth) {
            // Nothing - will be replaced
        },
        daysReady: function(refreshCallback) {
            console.log("Regisering days list");
        this.dayRefresh = refreshCallback;
        },
        handleMonthChange: function(monthIx) {
            console.log("New month");
            this.dayRefresh(monthIx);
        },
        handleDayChange: function(dayIx) {
            console.log("New DAY: " + dayIx);
        },
        render: function() {
            return(
                <div id="orderDetails">
                    <DaysList id="dayPicker" dateHandler={this.handleDayChange} readyCallback = {this.daysReady} />
                    <MonthsList data={MONTHS_ARR} id="monthPicker" dateHandler={this.handleMonthChange}  />
                </div>
            );
        }
    });



    React.renderComponent(
        <LeftPanel />,
        document.getElementById('leftPanel')
    );

And the HTML for running the left panel component index.html

<!DOCTYPE html>
<html>
<head>
    <title>Dates</title>

    <script src="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.6.0/underscore-min.js"></script>
    <script src="//fb.me/react-0.11.1.js"></script>
    <script src="//fb.me/JSXTransformer-0.11.1.js"></script>
</head>

    <style>

        #dayPicker {
            position: relative;
            top: 97px;
            left: 20px;
            width: 60px;
            height: 17px;
        }

        #monthPicker {
            position: relative;
            top: 97px;
            left: 22px;
            width: 95px;
            height: 17px;
        }

        select {
            font-size: 11px;
        }

    </style>


    <body>
        <div id="leftPanel">
        </div>

        <script type="text/jsx" src="dates.js"></script>

    </body>
</html>

Using global variables between files?

The problem is you defined myList from main.py, but subfile.py needs to use it. Here is a clean way to solve this problem: move all globals to a file, I call this file settings.py. This file is responsible for defining globals and initializing them:

# settings.py

def init():
    global myList
    myList = []

Next, your subfile can import globals:

# subfile.py

import settings

def stuff():
    settings.myList.append('hey')

Note that subfile does not call init()— that task belongs to main.py:

# main.py

import settings
import subfile

settings.init()          # Call only once
subfile.stuff()         # Do stuff with global var
print settings.myList[0] # Check the result

This way, you achieve your objective while avoid initializing global variables more than once.

How can I get the browser's scrollbar sizes?

It seems to work, but maybe there is a simpler solution that works in all browsers?

_x000D_

// Create the measurement node_x000D_
var scrollDiv = document.createElement("div");_x000D_
scrollDiv.className = "scrollbar-measure";_x000D_
document.body.appendChild(scrollDiv);_x000D_
_x000D_
// Get the scrollbar width_x000D_
var scrollbarWidth = scrollDiv.offsetWidth - scrollDiv.clientWidth;_x000D_
console.info(scrollbarWidth); // Mac:  15_x000D_
_x000D_
// Delete the DIV _x000D_
document.body.removeChild(scrollDiv);

_x000D_

.scrollbar-measure {_x000D_
 width: 100px;_x000D_
 height: 100px;_x000D_
 overflow: scroll;_x000D_
 position: absolute;_x000D_
 top: -9999px;_x000D_
}

_x000D_

How to center horizontal table-cell

Just add this class in your css

.column p{
   text-align:center;
}

PHP Header redirect not working

If I understand correctly, something has already sent out from header.php (maybe some HTML) so the headers have been set. You may need to recheck your header.php file for any part that may output HTML or spaces before your first

EDIT: I am now sure that it is caused from header.php since you have those HTML output. You can fix this by remove the "include('header.php');" line and copy the following code to your file instead.

include('class.user.php');
include('class.Connection.php');

        $date = date('Y-m-j');

How to close Android application?

The best and shortest way to use the table System.exit.

System.exit(0);

The VM stops further execution and program will exit.

How to count lines of Java code using IntelliJ IDEA?

Just like Neil said:

Ctrl-Shift-F -> Text to find = '\n' -> Find.

With only one improvement, if you enter "\n+", you can search for non-empty lines

If lines with only whitespace can be considered empty too, then you can use the regex "(\s*\n\s*)+" to not count them.

Execution failed for task :':app:mergeDebugResources'. Android Studio

For me. I changed the color of .xml image (vector image) like this.

ic_action_add.xml

  <vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="24dp"
    android:height="24dp"
    android:viewportWidth="24"
    android:viewportHeight="24"
    android:tint="#FFFFFF"
    android:alpha="0.8">
  <path
      android:fillColor="@android:color/white"
      android:pathData="M19,13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z"/>
</vector>

to:

<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="24dp"
    android:height="24dp"
    android:viewportWidth="24"
    android:viewportHeight="24"
    android:tint="#FFFFFF"
    android:alpha="0.8">
  <path
      android:fillColor="#FF000000"
      android:pathData="M19,13h-6v6h-2v-6H5v-2h6V5h2v6h6v2z"/>
</vector>

i just changed android:fillColor="@android:color/white" to android:fillColor="#FF000000"

and it's worked for me :)

How to remove empty lines with or without whitespace in Python

My version:

while '' in all_lines:
    all_lines.pop(all_lines.index(''))

Regex Named Groups in Java

Yes but its messy hacking the sun classes. There is a simpler way:

http://code.google.com/p/named-regexp/

named-regexp is a thin wrapper for the standard JDK regular expressions implementation, with the single purpose of handling named capturing groups in the .net style : (?...).

It can be used with Java 5 and 6 (generics are used).

Java 7 will handle named capturing groups , so this project is not meant to last.

How to navigate through textfields (Next / Done Buttons)

This is an old post, but has a high page rank so I'll chime in with my solution.

I had a similar issue and ended up creating a subclass of UIToolbar to manage the next/previous/done functionality in a dynamic tableView with sections: https://github.com/jday001/DataEntryToolbar

You set the toolbar as inputAccessoryView of your text fields and add them to its dictionary. This allows you to cycle through them forwards and backwards, even with dynamic content. There are delegate methods if you want to trigger your own functionality when textField navigation happens, but you don't have to deal with managing any tags or first responder status.

There are code snippets & an example app at the GitHub link to help with the implementation details. You will need your own data model to keep track of the values inside the fields.

Is it ok having both Anacondas 2.7 and 3.5 installed in the same time?

I have python 2.7.13 and 3.6.2 both installed. Install Anaconda for python 3 first and then you can use conda syntax to get 2.7. My install used: conda create -n py27 python=2.7.13 anaconda

Twitter Bootstrap Datepicker within modal window

For BootsTrap Calender use this

/The Calender Index CSS/

.bootstrap-datetimepicker-widget {
   z-index:99999 !important;
}

How to use filesaver.js

For people who want to load it in the console :

var s = document.createElement('script');
s.type = 'text/javascript';
s.src = 'https://cdnjs.cloudflare.com/ajax/libs/FileSaver.js/1.3.8/FileSaver.min.js';
document.body.appendChild(s);

Then :

saveAs(new Blob([data], {type: "application/octet-stream ;charset=utf-8"}), "video.ts")

File will be save when you're out of a breakpoint (at least on Chrome)

How to convert an NSTimeInterval (seconds) into minutes

Brief Description

The answer from Brian Ramsay is more convenient if you only want to convert to minutes.
If you want Cocoa API do it for you and convert your NSTimeInterval not only to minutes but also to days, months, week, etc,... I think this is a more generic approach
Use NSCalendar method:
- (NSDateComponents *)components:(NSUInteger)unitFlags fromDate:(NSDate *)startingDate toDate:(NSDate *)resultDate options:(NSUInteger)opts
- "Returns, as an NSDateComponents object using specified components, the difference between two supplied dates". From the API documentation.
Create 2 NSDate whose difference is the NSTimeInterval you want to convert. (If your NSTimeInterval comes from comparing 2 NSDate you don't need to do this step, and you don't even need the NSTimeInterval).
Get your quotes from NSDateComponents

Sample Code

// The time interval 
NSTimeInterval theTimeInterval = 326.4;

// Get the system calendar
NSCalendar *sysCalendar = [NSCalendar currentCalendar];

// Create the NSDates
NSDate *date1 = [[NSDate alloc] init];
NSDate *date2 = [[NSDate alloc] initWithTimeInterval:theTimeInterval sinceDate:date1]; 

// Get conversion to months, days, hours, minutes
unsigned int unitFlags = NSHourCalendarUnit | NSMinuteCalendarUnit | NSDayCalendarUnit | NSMonthCalendarUnit;

NSDateComponents *conversionInfo = [sysCalendar components:unitFlags fromDate:date1  toDate:date2  options:0];

NSLog(@"Conversion: %dmin %dhours %ddays %dmoths",[conversionInfo minute], [conversionInfo hour], [conversionInfo day], [conversionInfo month]);

[date1 release];
[date2 release];

Known issues

Too much for just a conversion, you are right, but that's how the API works.
My suggestion: if you get used to manage your time data using NSDate and NSCalendar, the API will do the hard work for you.

MySQL: Delete all rows older than 10 minutes

The answer is right in the MYSQL manual itself.

"DELETE FROM `table_name` WHERE `time_col` < ADDDATE(NOW(), INTERVAL -1 HOUR)"

write() versus writelines() and concatenated strings

if you just want to save and load a list try Pickle

Pickle saving:

with open("yourFile","wb")as file:
 pickle.dump(YourList,file)

and loading:

with open("yourFile","rb")as file:
 YourList=pickle.load(file)

Variable scoping in PowerShell

500.21 Bad module "ManagedPipelineHandler" in its module list

Try switching to Integrated mode. See the following thread:

IIS 7, HttpHandler and HTTP Error 500.21

How to bind inverse boolean properties in WPF?

I did something very similar. I created my property behind the scenes that enabled the selection of a combobox ONLY if it had finished searching for data. When my window first appears, it launches an async loaded command but I do not want the user to click on the combobox while it is still loading data (would be empty, then would be populated). So by default the property is false so I return the inverse in the getter. Then when I'm searching I set the property to true and back to false when complete.

private bool _isSearching;
public bool IsSearching
{
    get { return !_isSearching; }
    set
    {
        if(_isSearching != value)
        {
            _isSearching = value;
            OnPropertyChanged("IsSearching");
        }
    }
}

public CityViewModel()
{
    LoadedCommand = new DelegateCommandAsync(LoadCity, LoadCanExecute);
}

private async Task LoadCity(object pArg)
{
    IsSearching = true;

    //**Do your searching task here**

    IsSearching = false;
}

private bool LoadCanExecute(object pArg)
{
    return IsSearching;
}

Then for the combobox I can bind it directly to the IsSearching:

<ComboBox ItemsSource="{Binding Cities}" IsEnabled="{Binding IsSearching}" DisplayMemberPath="City" />

type object 'datetime.datetime' has no attribute 'datetime'

If you have used:

from datetime import datetime

Then simply write the code as:

date = datetime(int(year), int(month), 1)

But if you have used:

import datetime

then only you can write:

date = datetime.datetime(int(2005), int(5), 1)

Sending mass email using PHP

You can use swiftmailer for it. By using batch process.

<?php
    $message = Swift_Message::newInstance()
      ->setSubject('Let\'s get together today.')
      ->setFrom(array('[email protected]' => 'From Me'))
      ->setBody('Here is the message itself')
      ->addPart('<b>Test message being sent!!</b>', 'text/html');

    $data = mysql_query('SELECT first, last, email FROM users WHERE is_active=1') or die(mysql_error());
    while($row = mysql_fetch_assoc($data))
    {
       $message->addTo($row['email'], $row['first'] . ' ' . $row['last']);
    }

    $message->batchSend();
?>

How get all values in a column using PHP?

How to put MySQL functions back into PHP 7
Step 1

First get the mysql extension source which was removed in March:

https://github.com/php/php-src/tree/PRE_PHP7_EREG_MYSQL_REMOVALS/ext/mysql

Step 2

Then edit your php.ini

Somewhere either in the “Extensions” section or “MySQL” section, simply add this line:

extension = /usr/local/lib/php/extensions/no-debug-non-zts-20141001/mysql.so

Step 3

Restart PHP and mysql_* functions should now be working again.

Step 4

Turn off all deprecated warnings including them from mysql_*:

error_reporting(E_ALL ^ E_DEPRECATED);

Now Below Code Help You :

$result = mysql_query("SELECT names FROM Customers");
$Data= Array();
while ($row = mysql_fetch_array($result, MYSQL_ASSOC)) 
{
        $Data[] =  $row['names'];  
}

You can also get all values in column using mysql_fetch_assoc

$result = mysql_query("SELECT names FROM Customers");
    $Data= Array();
    while ($row = mysql_fetch_assoc($result)) 
    {
            $Data[] =  $row['names'];  
    }

This extension was deprecated in PHP 5.5.0, and it was removed in PHP 7.0.0. Instead, the MySQLi or PDO_MySQL extension should be used.

Reference

YOU CAN USE MYSQLI ALTERNATIVE OF MYSQL EASY WAY

<?php
$con=mysqli_connect("localhost","my_user","my_password","my_db");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

$sql="SELECT Lastname,Age FROM Persons ORDER BY Lastname";
$result=mysqli_query($con,$sql);

// Numeric array
$row=mysqli_fetch_array($result,MYSQLI_NUM);
printf ("%s (%s)\n",$row[0],$row[1]);

// Associative array
$row=mysqli_fetch_array($result,MYSQLI_ASSOC);
printf ("%s (%s)\n",$row["Lastname"],$row["Age"]);

// Free result set
mysqli_free_result($result);

mysqli_close($con);
?>

Stop all active ajax requests in jQuery

I extended mkmurray and SpYk3HH answer above so that xhrPool.abortAll can abort all pending requests of a given url :

$.xhrPool = [];
$.xhrPool.abortAll = function(url) {
    $(this).each(function(i, jqXHR) { //  cycle through list of recorded connection
        console.log('xhrPool.abortAll ' + jqXHR.requestURL);
        if (!url || url === jqXHR.requestURL) {
            jqXHR.abort(); //  aborts connection
            $.xhrPool.splice(i, 1); //  removes from list by index
        }
    });
};
$.ajaxSetup({
    beforeSend: function(jqXHR) {
        $.xhrPool.push(jqXHR); //  add connection to list
    },
    complete: function(jqXHR) {
        var i = $.xhrPool.indexOf(jqXHR); //  get index for current connection completed
        if (i > -1) $.xhrPool.splice(i, 1); //  removes from list by index
    }
});
$.ajaxPrefilter(function(options, originalOptions, jqXHR) {
    console.log('ajaxPrefilter ' + options.url);
    jqXHR.requestURL = options.url;
});

Usage is same except that abortAll can now optionally accept a url as a parameter and will cancel only pending calls to that url

how to delete all commit history in github?

Deleting the .git folder may cause problems in your git repository. If you want to delete all your commit history but keep the code in its current state, it is very safe to do it as in the following:

Checkout

git checkout --orphan latest_branch
Add all the files

git add -A
Commit the changes

git commit -am "commit message"
Delete the branch

git branch -D main
Rename the current branch to main

git branch -m main
Finally, force update your repository

git push -f origin main

PS: this will not keep your old commit history around

Overflow-x:hidden doesn't prevent content from overflowing in mobile browsers

I had tried many ways from replies in this topic, mostly works but got some side-effect like if I use overflow-x on body,html it might slow/freeze the page when users scroll down on mobile.

use position: fixed on wrapper/div inside the body is good too, but when I have a menu and use Javascript click animated scroll to some section, It's not working.

So, I decided to use touch-action: pan-y pinch-zoom on wrapper/div inside the body. Problem solved.

One line if/else condition in linux shell scripting

It looks as if you were on the right track. You just need to add the else statement after the ";" following the "then" statement. Also I would split the first line from the second line with a semicolon instead of joining it with "&&".

maxline='cat journald.conf | grep "#SystemMaxUse="'; if [ $maxline == "#SystemMaxUse=" ]; then sed 's/\#SystemMaxUse=/SystemMaxUse=50M/g' journald.conf > journald.conf2 && mv journald.conf2 journald.conf; else echo "This file has been edited. You'll need to do it manually."; fi

Also in your original script, when declaring maxline you used back-ticks "`" instead of single quotes "'" which might cause problems.

Sort dataGridView columns in C# ? (Windows Form)

You can control the data returned from SQL database by ordering the data returned:

orderby [Name]

If you execute the SQL query from your application, order the data returned. For example, make a function that calls the procedure or executes the SQL and give it a parameter that gets the orderby criteria. Because if you ordered the data returned from database it will consume time but order it since it's executed as you say that you want it to be ordered not from the UI you want it to be ordered in the run time so order it when executing the SQL query.

Getting started with OpenCV 2.4 and MinGW on Windows 7

As pointed out by @Nenad Bulatovic one has to be careful while adding libraries(19th step). one should not add any trailing spaces while adding each library line by line. otherwise mingw goes haywire.

Order a MySQL table by two columns

Default sorting is ascending, you need to add the keyword DESC to both your orders:

ORDER BY article_rating DESC, article_time DESC

Load a UIView from nib in Swift

Swift 5 - Clean and easy to use extension

[Copy Paste from production project]

//
//  Refactored by Essam Mohamed Fahmi.
//

import UIKit

extension UIView
{
   static var nib: UINib
   {
      return UINib(nibName: "\(self)", bundle: nil)
   }

   static func instantiateFromNib() -> Self?
   {
      return nib.instantiate() as? Self
   }
}

extension UINib
{
   func instantiate() -> Any?
   {
      return instantiate(withOwner: nil, options: nil).first
   }
}

Usage

let myCustomView: CustomView = .instantiateFromNib()

JPA EntityManager: Why use persist() over merge()?

Persist and merge are for two different purposes (they aren't alternatives at all).

(edited to expand differences information)

persist:

Insert a new register to the database
Attach the object to the entity manager.

merge:

Find an attached object with the same id and update it.
If exists update and return the already attached object.
If doesn't exist insert the new register to the database.

persist() efficiency:

It could be more efficient for inserting a new register to a database than merge().
It doesn't duplicates the original object.

persist() semantics:

It makes sure that you are inserting and not updating by mistake.

Example:

{
    AnyEntity newEntity;
    AnyEntity nonAttachedEntity;
    AnyEntity attachedEntity;

    // Create a new entity and persist it        
    newEntity = new AnyEntity();
    em.persist(newEntity);

    // Save 1 to the database at next flush
    newEntity.setValue(1);

    // Create a new entity with the same Id than the persisted one.
    AnyEntity nonAttachedEntity = new AnyEntity();
    nonAttachedEntity.setId(newEntity.getId());

    // Save 2 to the database at next flush instead of 1!!!
    nonAttachedEntity.setValue(2);
    attachedEntity = em.merge(nonAttachedEntity);

    // This condition returns true
    // merge has found the already attached object (newEntity) and returns it.
    if(attachedEntity==newEntity) {
            System.out.print("They are the same object!");
    }

    // Set 3 to value
    attachedEntity.setValue(3);
    // Really, now both are the same object. Prints 3
    System.out.println(newEntity.getValue());

    // Modify the un attached object has no effect to the entity manager
    // nor to the other objects
    nonAttachedEntity.setValue(42);
}

This way only exists 1 attached object for any register in the entity manager.

merge() for an entity with an id is something like:

AnyEntity myMerge(AnyEntity entityToSave) {
    AnyEntity attached = em.find(AnyEntity.class, entityToSave.getId());
    if(attached==null) {
            attached = new AnyEntity();
            em.persist(attached);
    }
    BeanUtils.copyProperties(attached, entityToSave);

    return attached;
}

Although if connected to MySQL merge() could be as efficient as persist() using a call to INSERT with ON DUPLICATE KEY UPDATE option, JPA is a very high level programming and you can't assume this is going to be the case everywhere.

How to change the project in GCP using CLI commands

Also, if you are using more than one project and don't want to set global project every time, you can use select project flag.

For example: to connect a virtual machine, named my_vm under a project named my_project in Google Cloud Platform:

gcloud --project my_project compute ssh my_vm

This way, you can work with multiple project and change between them easily by just putting project flag. You can find much more information about other GCP flags from here.

How to force a line break in a long word in a DIV?

From MDN:

The overflow-wrap CSS property specifies whether or not the browser should insert line breaks within words to prevent text from overflowing its content box.

In contrast to word-break, overflow-wrap will only create a break if an entire word cannot be placed on its own line without overflowing.

So you can use:

overflow-wrap: break-word;

Can I use?

How to fix itunes could not connect to the iphone because an invalid response was received from the device?

Try resetting your network settings

Settings -> General -> Reset -> Reset Network Settings

And try deleting the contents of your mac/pc lockdown folder. Here's the link, follow the steps on "Reset the Lockdown folder".

http://support.apple.com/kb/ts2529

This one worked for me.

How do you Hover in ReactJS? - onMouseLeave not registered during fast hover over

you can use onMouseOver={this.onToggleOpen} and onMouseOut={this.onToggleOpen} to muse over and out on component

Assign width to half available screen width declaratively

Using constraints layout

Add a Guideline
Set the percentage to 50%
Constrain your view to the Guideline and the parent.

If you are having trouble changing it to a percentage, then see this answer.

XML

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:layout_editor_absoluteX="0dp"
    tools:layout_editor_absoluteY="81dp">

    <android.support.constraint.Guideline
        android:id="@+id/guideline8"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.5"/>

    <TextView
        android:id="@+id/textView6"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="TextView"
        app:layout_constraintBottom_toTopOf="@+id/guideline8"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>
    
</android.support.constraint.ConstraintLayout>

Path.Combine for URLs?

Path.Combine("Http://MyUrl.com/", "/Images/Image.jpg").Replace("\\", "/")

how to read a text file using scanner in Java?

Well.. Apparently the file does not exist or cannot be found. Try using a full path. You're probably reading from the wrong directory when you don't specify the path, unless a.txt is in your current working directory.

Best way to represent a fraction in Java?

A clean up practice that I like is to only have only one return.

 public int compareTo(Fraction frac) {
        int result = 0
        double t = this.doubleValue();
        double f = frac.doubleValue();
        if(t>f) 
           result = 1;
        else if(f>t) 
           result -1;
        return result;
    }

Choosing bootstrap vs material design

As far as I know you can use all mentioned technologies separately or together. It's up to you. I think you look at the problem from the wrong angle. Material Design is just the way particular elements of the page are designed, behave and put together. Material Design provides great UI/UX, but it relies on the graphic layout (HTML/CSS) rather than JS (events, interactions).

On the other hand, AngularJS and Bootstrap are front-end frameworks that can speed up your development by saving you from writing tons of code. For example, you can build web app utilizing AngularJS, but without Material Design. Or You can build simple HTML5 web page with Material Design without AngularJS or Bootstrap. Finally you can build web app that uses AngularJS with Bootstrap and with Material Design. This is the best scenario. All technologies support each other.

Bootstrap = responsive page
AngularJS = MVC
Material Design = great UI/UX

You can check awesome material design components for AngularJS:

https://material.angularjs.org

enter image description here

Demo: https://material.angularjs.org/latest/demo/ enter image description here

Convert string to float?

Using Float.parseFloat()?

class Test {
    public static void main(String[] args) {
        String s = "3.14";
        float f = Float.parseFloat(s);
        System.out.println(f);
    }
}

Java : Sort integer array without using Arrays.sort()

here is the Sorting Simple Example try it

public class SortingSimpleExample {

    public static void main(String[] args) {
        int[] a={10,20,1,5,4,20,6,4,2,5,4,6,8,-5,-1};
              a=sort(a);
        for(int i:a)
              System.out.println(i);
}
    public static int[] sort(int[] a){

        for(int i=0;i<a.length;i++){
            for(int j=0;j<a.length;j++){
                int temp=0;
                if(a[i]<a[j]){
                    temp=a[j];                  
                    a[j]=a[i];                  
                    a[i]=temp;      
                  }         
                }
        }
        return a;

    }
}

Extracting numbers from vectors of strings

Update Since extract_numeric is deprecated, we can use parse_number from readr package.

library(readr)
parse_number(years)

Here is another option with extract_numeric

library(tidyr)
extract_numeric(years)
#[1] 20  1

How to checkout in Git by date?

In my case the -n 1 option doesn't work. On Windows I've found that the following sequence of commands works fine:

git rev-list -1 --before="2012-01-15 12:00" master

This returns the appropriate commit's SHA for the given date, and then:

git checkout SHA

Button Width Match Parent

 new SizedBox(
  width: 100.0,
     child: new RaisedButton(...),
)

No module named Image

Did you setup PIL module? Link

You can try to reinstall it on your computer.

android image button

You just use an ImageButton and make the background whatever you want and set the icon as the src.

<ImageButton
    android:id="@+id/ImageButton01"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/album_icon"
    android:background="@drawable/round_button" />

How can I concatenate a string and a number in Python?

You have to convert the int into a string:

"abc" + str(9)

How could I create a list in c++?

If you are going to use std::list, you need to pass a type parameter:

list<int> intList;  
list<int>* intListPtr = new list<int>;

If you want to know how lists work, I recommending googling for some C/C++ tutorials to gain an understanding of that subject. Next step would then be learning enough C++ to create a list class, and finally a list template class.

If you have more questions, ask back here.

Server configuration by allow_url_fopen=0 in

Using relative instead of absolute file path solved the problem for me. I had the same issue and setting allow_url_fopen=on did not help. This means for instance :

use $file="folder/file.ext"; instead of $file="https://website.com/folder/file.ext"; in

$f=fopen($file,"r+");

Cannot run emulator in Android Studio

A common approach to follow to solve this problem.

1.CHECK your SDK manager by running from your android studio and stand alons sdk folder by executing ./android.sh helps you to find broken packages

Try installing System emulator images with google API support than the Intel one. Just like , i solved my problem by running into another system image.
Experment on KVM based Virtulaization suggested by Google for Linux

How should I choose an authentication library for CodeIgniter?

Also take a look at BackendPro

Ultimately you will probably end up writing something custom, but there's nothing wrong with borrowing concepts from DX Auth, Freak Auth, BackendPro, etc.

My experiences with the packaged apps is they are specific to certain structures and I have had problems integrating them into my own applications without requiring hacks, then if the pre-package has an update, I have to migrate them in.

I also use Smarty and ADOdb in my CI code, so no matter what I would always end up making major code changes.

Prime numbers between 1 to 100 in C Programming Language

#include <stdio.h>

int main () {

   int i, j;

   for(i = 2; i<100; i++) {

      for(j = 2; j <= (i/j); j++) 
      if(!(i%j)) break; // if factor found, not prime
      if(j > (i/j)) printf("%d is prime", i);
   }

   return 0;
}

How to shutdown a Spring Boot Application in a correct way?

SpringApplication implicitly registers a shutdown hook with the JVM to ensure that ApplicationContext is closed gracefully on exit. That will also call all bean methods annotated with @PreDestroy. That means we don't have to explicitly use the registerShutdownHook() method of a ConfigurableApplicationContext in a boot application, like we have to do in spring core application.

@SpringBootConfiguration
public class ExampleMain {
    @Bean
    MyBean myBean() {
        return new MyBean();
    }

    public static void main(String[] args) {
        ApplicationContext context = SpringApplication.run(ExampleMain.class, args);
        MyBean myBean = context.getBean(MyBean.class);
        myBean.doSomething();

        //no need to call context.registerShutdownHook();
    }

    private static class MyBean {

        @PostConstruct
        public void init() {
            System.out.println("init");
        }

        public void doSomething() {
            System.out.println("in doSomething()");
        }

        @PreDestroy
        public void destroy() {
            System.out.println("destroy");
        }
    }
}

How to flush output after each `echo` call?

This works fine for me (Apache 2.4/PHP 7.0):

@ob_end_clean();
echo "lorem ipsum...";
flush();
sleep(5);
echo "<br>dolor...";
flush();
sleep(5);
echo "<br>sit amet";

Alternative to Intersect in MySQL

AFAIR, MySQL implements INTERSECT through INNER JOIN.

how to hide keyboard after typing in EditText in android?

int klavStat = 1; // for keyboard soft/hide button
int inType;  // to remeber your default keybort Type

editor - is EditText field

/// metod for onclick button ///
public void keyboard(View view) {
    if (klavStat == 1) {
        klavStat = 0;
        
        inType = editor.getInputType();
        
        InputMethodManager imm = (InputMethodManager)
                getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS);
     

        editor.setInputType(InputType.TYPE_NULL);

        editor.setTextIsSelectable(true);
    } else {
        klavStat = 1;


        InputMethodManager imm = (InputMethodManager)
                getSystemService(Context.INPUT_METHOD_SERVICE);

        imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT, 0);

        editor.setInputType(inType);
    }
}

If you have another EditText Field, you need to watch for focus change.

PHP Curl And Cookies

You can define different cookies for every user with CURLOPT_COOKIEFILE and CURLOPT_COOKIEJAR. Make different file for every user so each one would have it's own cookie-based session on remote server.

"The stylesheet was not loaded because its MIME type, "text/html" is not "text/css"

Review any .htaccess. Maybe, a .htaccess rule is interfering with the right output. Try browsing your CSS resource directly in your address bar, it must be presented in text format.

Node.js ES6 classes with require

Just treat the ES6 class name the same as you would have treated the constructor name in the ES5 way. They are one and the same.

The ES6 syntax is just syntactic sugar and creates exactly the same underlying prototype, constructor function and objects.

So, in your ES6 example with:

// animal.js
class Animal {
    ...
}

var a = new Animal();

module.exports = {Animal: Animal};

You can just treat Animal like the constructor of your object (the same as you would have done in ES5). You can export the constructor. You can call the constructor with new Animal(). Everything is the same for using it. Only the declaration syntax is different. There's even still an Animal.prototype that has all your methods on it. The ES6 way really does create the same coding result, just with fancier/nicer syntax.

On the import side, this would then be used like this:

const Animal = require('./animal.js').Animal;

let a = new Animal();

This scheme exports the Animal constructor as the .Animal property which allows you to export more than one thing from that module.

If you don't need to export more than one thing, you can do this:

// animal.js
class Animal {
    ...
}

module.exports = Animal;

And, then import it with:

const Animal = require('./animal.js');

let a = new Animal();

Strip spaces/tabs/newlines - python

import re

mystr = "I want to Remove all white \t spaces, new lines \n and tabs \t"
print re.sub(r"\W", "", mystr)

Output : IwanttoRemoveallwhitespacesnewlinesandtabs

hibernate: LazyInitializationException: could not initialize proxy

use Hibernate.initialize for lazy field

.aspx vs .ashx MAIN difference

For folks that have programmed in nodeJs before, particularly using expressJS. I think of .ashx as a middleware that calls the next function. While .aspx will be the controller that actually responds to the request either around res.redirect, res.send or whatever.

error: expected class-name before ‘{’ token

Replace

#include "Landing.h"

with

class Landing;

If you still get errors, also post Item.h, Flight.h and common.h

EDIT: In response to comment.

You will need to e.g. #include "Landing.h" from Event.cpp in order to actually use the class. You just cannot include it from Event.h

How do you remove a Cookie in a Java Servlet

One special case: a cookie has no path.

In this case set path as cookie.setPath(request.getRequestURI())

The javascript sets cookie without path so the browser shows it as cookie for the current page only. If I try to send the expired cookie with path == / the browser shows two cookies: one expired with path == / and another one with path == current page.

CSS display: inline vs inline-block

Inline elements:

respect left & right margins and padding, but not top & bottom
cannot have a width and height set
allow other elements to sit to their left and right.
see very important side notes on this here.

Block elements:

respect all of those
force a line break after the block element
acquires full-width if width not defined

Inline-block elements:

allow other elements to sit to their left and right
respect top & bottom margins and padding
respect height and width

From W3Schools:

An inline element has no line break before or after it, and it tolerates HTML elements next to it.

A block element has some whitespace above and below it and does not tolerate any HTML elements next to it.

An inline-block element is placed as an inline element (on the same line as adjacent content), but it behaves as a block element.

When you visualize this, it looks like this:

CSS block vs inline vs inline-block

The image is taken from this page, which also talks some more about this subject.

Excel VBA select range at last row and column

Is this what you are trying? I have commented the code so that you will not have any problem understanding it.

Sub Sample()
    Dim ws As Worksheet
    Dim lRow As Long, lCol As Long
    Dim rng As Range

    '~~> Set this to the relevant worksheet
    Set ws = [Sheet1]

    With ws
        '~~> Get the last row and last column
        lRow = .Range("A" & .Rows.Count).End(xlUp).Row
        lCol = .Cells(1, .Columns.Count).End(xlToLeft).Column

        '~~> Set the range
        Set rng = .Range(.Cells(lRow, 1), .Cells(lRow, lCol))

        With rng
            Debug.Print .Address
            '
            '~~> What ever you want to do with the address
            '
        End With
    End With
End Sub

BTW I am assuming that LastRow is the same for all rows and same goes for the columns. If that is not the case then you will have use .Find to find the Last Row and the Last Column. You might want to see THIS

Best way to encode text data for XML

If you're serious about handling all of the invalid characters (not just the few "html" ones), and you have access to System.Xml, here's the simplest way to do proper Xml encoding of value data:

string theTextToEscape = "Something \x1d else \x1D <script>alert('123');</script>";
var x = new XmlDocument();
x.LoadXml("<r/>"); // simple, empty root element
x.DocumentElement.InnerText = theTextToEscape; // put in raw string
string escapedText = x.DocumentElement.InnerXml; // Returns:  Something &#x1D; else &#x1D; &lt;script&gt;alert('123');&lt;/script&gt;

// Repeat the last 2 lines to escape additional strings.

It's important to know that XmlConvert.EncodeName() is not appropriate, because that's for entity/tag names, not values. Using that would be like Url-encoding when you needed to Html-encode.

How do we determine the number of days for a given month in python

Just for the sake of academic interest, I did it this way...

(dt.replace(month = dt.month % 12 +1, day = 1)-timedelta(days=1)).day

TypeError: sequence item 0: expected string, int found

string.join connects elements inside list of strings, not ints.

Use this generator expression instead :

values = ','.join(str(v) for v in value_list)

How to add/update an attribute to an HTML element using JavaScript?

What do you want to do with the attribute? Is it an html attribute or something of your own?

Most of the time you can simply address it as a property: want to set a title on an element? element.title = "foo" will do it.

For your own custom JS attributes the DOM is naturally extensible (aka expando=true), the simple upshot of which is that you can do element.myCustomFlag = foo and subsequently read it without issue.

How to convert <font size="10"> to px?

This is really old, but <font size="10"> would be about <p style= "font-size:55px">

How to revert to origin's master branch's version of file

I've faced same problem and came across to this thread but my problem was with upstream. Below git command worked for me.

Syntax

git checkout {remoteName}/{branch} -- {../path/file.js}

Example

git checkout upstream/develop -- public/js/index.js

AssertionError: View function mapping is overwriting an existing endpoint function: main

Adding @wraps(f) above the wrapper function solved my issue.

def list_ownership(f):
    @wraps(f)
    def decorator(*args,**kwargs):
        return f(args,kwargs)
    return decorator

What does this symbol mean in IntelliJ? (red circle on bottom-left corner of file name, with 'J' in it)

This is what worked for me

Press File from the toolbar
Press Sync Project with Gradle Files

Reading local text file into a JavaScript array

Using Node.js

sync mode:

var fs = require("fs");
var text = fs.readFileSync("./mytext.txt");
var textByLine = text.split("\n")

async mode:

var fs = require("fs");
fs.readFile("./mytext.txt", function(text){
    var textByLine = text.split("\n")
});

UPDATE

As of at least Node 6, readFileSync returns a Buffer, so it must first be converted to a string in order for split to work:

var text = fs.readFileSync("./mytext.txt").toString('utf-8');

var text = fs.readFileSync("./mytext.txt", "utf-8");

Reset select value to default

Why not use a simple javascript function and call it on onclick event?

function reset(){
document.getElementById("my_select").selectedIndex = 1; //1 = option 2
}

Using Get-childitem to get a list of files modified in the last 3 days

Here's a minor update to the solution provided by Dave Sexton. Many times you need multiple filters. The Filter parameter can only take a single string whereas the -Include parameter can take a string array. if you have a large file tree it also makes sense to only get the date to compare with once, not for each file. Here's my updated version:

$compareDate = (Get-Date).AddDays(-3)    
@(Get-ChildItem -Path c:\pstbak\*.* -Filter '*.pst','*.mdb' -Recurse | Where-Object { $_.LastWriteTime -gt $compareDate}).Count

Convert row to column header for Pandas DataFrame,

It would be easier to recreate the data frame. This would also interpret the columns types from scratch.

headers = df.iloc[0]
new_df  = pd.DataFrame(df.values[1:], columns=headers)

Limiting the number of characters per line with CSS

You could do this:
(Note! This is CSS3 and the browser support = good!! )

   p {
    text-overflow: ellipsis; /* will make [...] at the end */
    width: 370px; /* change to your preferences */
    white-space: nowrap; /* paragraph to one line */
    overflow:hidden; /* older browsers */
    }

Sending a JSON HTTP POST request from Android

Posting parameters Using POST:-

URL url;
URLConnection urlConn;
DataOutputStream printout;
DataInputStream  input;
url = new URL (getCodeBase().toString() + "env.tcgi");
urlConn = url.openConnection();
urlConn.setDoInput (true);
urlConn.setDoOutput (true);
urlConn.setUseCaches (false);
urlConn.setRequestProperty("Content-Type","application/json");   
urlConn.setRequestProperty("Host", "android.schoolportal.gr");
urlConn.connect();  
//Create JSONObject here
JSONObject jsonParam = new JSONObject();
jsonParam.put("ID", "25");
jsonParam.put("description", "Real");
jsonParam.put("enable", "true");

The part which you missed is in the the following... i.e., as follows..

// Send POST output.
printout = new DataOutputStream(urlConn.getOutputStream ());
printout.writeBytes(URLEncoder.encode(jsonParam.toString(),"UTF-8"));
printout.flush ();
printout.close ();

The rest of the thing you can do it.

jQuery Uncaught TypeError: Cannot read property 'fn' of undefined (anonymous function)

I had the same problem when using bootstrap-datewidget and i loaded jquery in the header instead of loading it at the end of the body and it worked.

"SELECT ... IN (SELECT ...)" query in CodeIgniter

I think you can create a simple SQL query:

$sql="select username from user where id in (select id from idtables)";
$query=$this->db->query($sql);

and then you can use it normally.

Find something in column A then show the value of B for that row in Excel 2010

Assuming

source data range is A1:B100.
query cell is D1 (here you will input Police or Fire).
result cell is E1

Formula in E1 = VLOOKUP(D1, A1:B100, 2, FALSE)

Multiple argument IF statement - T-SQL

Not sure what the problem is, this seems to work just fine?

DECLARE @StartDate AS DATETIME
DECLARE @EndDate AS DATETIME

SET @StartDate = NULL
SET @EndDate = NULL

IF (@StartDate IS NOT NULL AND @EndDate IS NOT NULL) 
    BEGIN
        Select 'This works just fine' as Msg
    END
Else
    BEGIN
    Select 'No Lol' as Msg
    END

Check whether a path is valid

Just Simply Use

if (System.IO.Directory.Exists(path))
{
    ...
}

CardView not showing Shadow in Android L

use app:cardUseCompatPadding="true" inside your cardview. For Example

<android.support.v7.widget.CardView
        android:id="@+id/card_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginRight="@dimen/cardviewMarginRight"
        app:cardBackgroundColor="@color/menudetailsbgcolor"
        app:cardCornerRadius="@dimen/cardCornerRadius"
        app:cardUseCompatPadding="true"
        app:elevation="0dp">
    </android.support.v7.widget.CardView>

Select mySQL based only on month and year

Here is a query that I use and it will return each record within a period as a sum.

Here is the code:

$result = mysqli_query($conn,"SELECT emp_nr, SUM(az) 
FROM az_konto 
WHERE date BETWEEN '2018-01-01 00:00:00' AND '2018-01-31 23:59:59' 
GROUP BY emp_nr ASC");

echo "<table border='1'>
<tr>
<th>Mitarbeiter NR</th>
<th>Stunden im Monat</th>
</tr>";

while($row = mysqli_fetch_array($result))
{
$emp_nr=$row['emp_nr'];
$az=$row['SUM(az)'];
echo "<tr>";
echo "<td>" . $emp_nr . "</td>";
echo "<td>" . $az . "</td>";
echo "</tr>";
}
echo "</table>";
$conn->close();
?>

This lists each emp_nr and the sum of the monthly hours that they have accumulated.

PL/pgSQL checking if a row exists

Use count(*)

declare 
   cnt integer;
begin
  SELECT count(*) INTO cnt
  FROM people
  WHERE person_id = my_person_id;

IF cnt > 0 THEN
  -- Do something
END IF;

Edit (for the downvoter who didn't read the statement and others who might be doing something similar)

The solution is only effective because there is a where clause on a column (and the name of the column suggests that its the primary key - so the where clause is highly effective)

Because of that where clause there is no need to use a LIMIT or something else to test the presence of a row that is identified by its primary key. It is an effective way to test this.

Detect rotation of Android phone in the browser with JavaScript

Another gotcha - some Android tablets (the Motorola Xoom I believe and a low-end Elonex one I'm doing some testing on, probably others too) have their accelerometers set up so that window.orientation == 0 in LANDSCAPE mode, not portrait!

Java: Add elements to arraylist with FOR loop where element name has increasing number

You can't do it the way you're trying to... can you perhaps do something like this:

List<Answer> answers = new ArrayList<Answer>();
for(int i=0; i < 4; i++){
  Answer temp = new Answer();
  //do whatever initialization you need here
  answers.add(temp);
}

xls to csv converter

I would use pandas. The computationally heavy parts are written in cython or c-extensions to speed up the process and the syntax is very clean. For example, if you want to turn "Sheet1" from the file "your_workbook.xls" into the file "your_csv.csv", you just use the top-level function read_excel and the method to_csv from the DataFrame class as follows:

import pandas as pd
data_xls = pd.read_excel('your_workbook.xls', 'Sheet1', index_col=None)
data_xls.to_csv('your_csv.csv', encoding='utf-8')

Setting encoding='utf-8' alleviates the UnicodeEncodeError mentioned in other answers.

Does not contain a definition for and no extension method accepting a first argument of type could be found

Declare an instance of the CBetfairAPI class or make it static.

Different class for the last element in ng-repeat

You could use limitTo filter with -1 for find the last element

Example :

<div ng-repeat="friend in friends | limitTo: -1">
    {{friend.name}}
</div>

How to quickly drop a user with existing privileges

Also note, if you have explicitly granted:

CONNECT ON DATABASE xxx TO GROUP ,

you will need to revoke this separately from DROP OWNED BY, using:

REVOKE CONNECT ON DATABASE xxx FROM GROUP

int to hex string

Previous answer is not good for negative numbers. Use a short type instead of int

        short iValue = -1400;
        string sResult = iValue.ToString("X2");
        Console.WriteLine("Value={0} Result={1}", iValue, sResult);

Now result is FA88

Group dataframe and get sum AND count?

Just in case you were wondering how to rename columns during aggregation, here's how for

pandas >= 0.25: Named Aggregation

df.groupby('Company Name')['Amount'].agg(MySum='sum', MyCount='count')

Or,

df.groupby('Company Name').agg(MySum=('Amount', 'sum'), MyCount=('Amount', 'count'))

                       MySum  MyCount
Company Name                       
Vifor Pharma UK Ltd  4207.93        5

How to delete projects in Intellij IDEA 14?

1. Choose project, right click, in context menu, choose Show in Explorer (on Mac, select Reveal in Finder).

enter image description here

2. Choose menu File \ Close Project

enter image description here

3. In Windows Explorer, press Del or Shift+Del for permanent delete.

4. At IntelliJ IDEA startup windows, hover cursor on old project name (what has been deleted) press Del for delelte.

enter image description here

Programs & Examples On #Python 2.1

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TL;DR $PATH fix

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jasmine: Async callback was not invoked within timeout specified by jasmine.DEFAULT_TIMEOUT_INTERVAL

Slide right to left Android Animations

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Linking to a specific part of a web page

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TL;DR version:

In detail:

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build failed with: ld: duplicate symbol _OBJC_CLASS_$_Algebra5FirstViewController

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<div style display="none" > inside a table not working