"Uncaught SyntaxError: Cannot use import statement outside a module" when importing ECMAScript 6

I don't know whether this has appeared obvious here. I would like to point out that as far as client-side (browser) JavaScript is concerned, you can add type="module" to both external as well as internal js scripts.

Say, you have a file 'module.js':

var a = 10;
export {a};

You can use it in an external script, in which you do the import, eg.:

<!DOCTYPE html><html><body>
<script type="module" src="test.js"></script><!-- Here use type="module" rather than type="text/javascript" -->
</body></html>

test.js:

import {a} from "./module.js";
alert(a);

You can also use it in an internal script, eg.:

<!DOCTYPE html><html><body>
<script type="module">
    import {a} from "./module.js";
    alert(a);
</script>
</body></html>

It is worthwhile mentioning that for relative paths, you must not omit the "./" characters, ie.:

import {a} from "module.js";     // this won't work

java.security.cert.CertificateException: Certificates does not conform to algorithm constraints

Since this result is the first that Google returns for this error, I'll just add that if anyone looks for way do change java security settings without changing the global file java.security (for example you need to run some tests), you can just provide an overriding security file by JVM parameter -Djava.security.properties=your/file/path in which you can enable the necessary algorithms by overriding the disablements.

How do I check out an SVN project into Eclipse as a Java project?

If it wasn't checked in as a Java Project, you can add the java nature as shown here.

How can you profile a Python script?

pprofile

line_profiler (already presented here) also inspired pprofile, which is described as:

Line-granularity, thread-aware deterministic and statistic pure-python profiler

It provides line-granularity as line_profiler, is pure Python, can be used as a standalone command or a module, and can even generate callgrind-format files that can be easily analyzed with [k|q]cachegrind.

vprof

There is also vprof, a Python package described as:

[...] providing rich and interactive visualizations for various Python program characteristics such as running time and memory usage.

How do I release memory used by a pandas dataframe?

Reducing memory usage in Python is difficult, because Python does not actually release memory back to the operating system. If you delete objects, then the memory is available to new Python objects, but not free()'d back to the system (see this question).

If you stick to numeric numpy arrays, those are freed, but boxed objects are not.

>>> import os, psutil, numpy as np
>>> def usage():
...     process = psutil.Process(os.getpid())
...     return process.get_memory_info()[0] / float(2 ** 20)
... 
>>> usage() # initial memory usage
27.5 

>>> arr = np.arange(10 ** 8) # create a large array without boxing
>>> usage()
790.46875
>>> del arr
>>> usage()
27.52734375 # numpy just free()'d the array

>>> arr = np.arange(10 ** 8, dtype='O') # create lots of objects
>>> usage()
3135.109375
>>> del arr
>>> usage()
2372.16796875  # numpy frees the array, but python keeps the heap big

Reducing the Number of Dataframes

Python keep our memory at high watermark, but we can reduce the total number of dataframes we create. When modifying your dataframe, prefer inplace=True, so you don't create copies.

Another common gotcha is holding on to copies of previously created dataframes in ipython:

In [1]: import pandas as pd

In [2]: df = pd.DataFrame({'foo': [1,2,3,4]})

In [3]: df + 1
Out[3]: 
   foo
0    2
1    3
2    4
3    5

In [4]: df + 2
Out[4]: 
   foo
0    3
1    4
2    5
3    6

In [5]: Out # Still has all our temporary DataFrame objects!
Out[5]: 
{3:    foo
 0    2
 1    3
 2    4
 3    5, 4:    foo
 0    3
 1    4
 2    5
 3    6}

You can fix this by typing %reset Out to clear your history. Alternatively, you can adjust how much history ipython keeps with ipython --cache-size=5 (default is 1000).

Reducing Dataframe Size

Wherever possible, avoid using object dtypes.

>>> df.dtypes
foo    float64 # 8 bytes per value
bar      int64 # 8 bytes per value
baz     object # at least 48 bytes per value, often more

Values with an object dtype are boxed, which means the numpy array just contains a pointer and you have a full Python object on the heap for every value in your dataframe. This includes strings.

Whilst numpy supports fixed-size strings in arrays, pandas does not (it's caused user confusion). This can make a significant difference:

>>> import numpy as np
>>> arr = np.array(['foo', 'bar', 'baz'])
>>> arr.dtype
dtype('S3')
>>> arr.nbytes
9

>>> import sys; import pandas as pd
>>> s = pd.Series(['foo', 'bar', 'baz'])
dtype('O')
>>> sum(sys.getsizeof(x) for x in s)
120

You may want to avoid using string columns, or find a way of representing string data as numbers.

If you have a dataframe that contains many repeated values (NaN is very common), then you can use a sparse data structure to reduce memory usage:

>>> df1.info()
<class 'pandas.core.frame.DataFrame'>
Int64Index: 39681584 entries, 0 to 39681583
Data columns (total 1 columns):
foo    float64
dtypes: float64(1)
memory usage: 605.5 MB

>>> df1.shape
(39681584, 1)

>>> df1.foo.isnull().sum() * 100. / len(df1)
20.628483479893344 # so 20% of values are NaN

>>> df1.to_sparse().info()
<class 'pandas.sparse.frame.SparseDataFrame'>
Int64Index: 39681584 entries, 0 to 39681583
Data columns (total 1 columns):
foo    float64
dtypes: float64(1)
memory usage: 543.0 MB

Viewing Memory Usage

You can view the memory usage (docs):

>>> df.info()
<class 'pandas.core.frame.DataFrame'>
Int64Index: 39681584 entries, 0 to 39681583
Data columns (total 14 columns):
...
dtypes: datetime64[ns](1), float64(8), int64(1), object(4)
memory usage: 4.4+ GB

As of pandas 0.17.1, you can also do df.info(memory_usage='deep') to see memory usage including objects.

forcing web-site to show in landscape mode only

@Golmaal really answered this, I'm just being a bit more verbose.

<style type="text/css">
    #warning-message { display: none; }
    @media only screen and (orientation:portrait){
        #wrapper { display:none; }
        #warning-message { display:block; }
    }
    @media only screen and (orientation:landscape){
        #warning-message { display:none; }
    }
</style>

....

<div id="wrapper">
    <!-- your html for your website -->
</div>
<div id="warning-message">
    this website is only viewable in landscape mode
</div>

You have no control over the user moving the orientation however you can at least message them. This example will hide the wrapper if in portrait mode and show the warning message and then hide the warning message in landscape mode and show the portrait.

I don't think this answer is any better than @Golmaal , only a compliment to it. If you like this answer, make sure to give @Golmaal the credit.

Update

I've been working with Cordova a lot recently and it turns out you CAN control it when you have access to the native features.

Another Update

So after releasing Cordova it is really terrible in the end. It is better to use something like React Native if you want JavaScript. It is really amazing and I know it isn't pure web but the pure web experience on mobile kind of failed.

PHP - Get key name of array value

If you have a value and want to find the key, use array_search() like this:

$arr = array ('first' => 'a', 'second' => 'b', );
$key = array_search ('a', $arr);

$key will now contain the key for value 'a' (that is, 'first').

Check if a number has a decimal place/is a whole number

You can use the bitwise operations that do not change the value (^ 0 or ~~) to discard the decimal part, which can be used for rounding. After rounding the number, it is compared to the original value:

function isDecimal(num) {
  return (num ^ 0) !== num;
}

console.log( isDecimal(1) ); // false
console.log( isDecimal(1.5) ); // true
console.log( isDecimal(-0.5) ); // true

difference between width auto and width 100 percent

Width auto

The initial width of a block level element like div or p is auto. This makes it expand to occupy all available horizontal space within its containing block. If it has any horizontal padding or border, the widths of those do not add to the total width of the element.

Width 100%

On the other hand, if you specify width:100%, the element’s total width will be 100% of its containing block plus any horizontal margin, padding and border (unless you’ve used box-sizing:border-box, in which case only margins are added to the 100% to change how its total width is calculated). This may be what you want, but most likely it isn’t.

To visualise the difference see this picture:

enter image description here

Source

how to increase java heap memory permanently?

This worked for me:

export _JAVA_OPTIONS="-Xmx1g"

It's important that you have no spaces because for me it did not work. I would suggest just copying and pasting. Then I ran:

java -XshowSettings:vm

and it will tell you:

Picked up _JAVA_OPTIONS: -Xmx1g

How to get an element by its href in jquery?

If you want to get any element that has part of a URL in their href attribute you could use:

$( 'a[href*="google.com"]' );

This will select all elements with a href that contains google.com, for example:

As stated by @BalusC in the comments below, it will also match elements that have google.com at any position in the href, like blahgoogle.com.

How to override !important?

Overriding the !important modifier

Simply add another CSS rule with !important, and give the selector a higher specificity (adding an additional tag, id or class to the selector)
add a CSS rule with the same selector at a later point than the existing one (in a tie, the last one defined wins).

Some examples with a higher specificity (first is highest/overrides, third is lowest):

table td    {height: 50px !important;}
.myTable td {height: 50px !important;}
#myTable td {height: 50px !important;}

Or add the same selector after the existing one:

td {height: 50px !important;}

Disclaimer:

It's almost never a good idea to use !important. This is bad engineering by the creators of the WordPress template. In viral fashion, it forces users of the template to add their own !important modifiers to override it, and it limits the options for overriding it via JavaScript.

But, it's useful to know how to override it, if you sometimes have to.

MySQL Stored procedure variables from SELECT statements

I am facing a strange behavior.

SELECT INTO and SET Both works for some variables and not for others. Event syntaxes are the same

SET @Invoice_UserId :=  (SELECT UserId FROM invoice WHERE InvoiceId = @Invoice_Id  LIMIT 1); -- Working
                SET @myamount := (SELECT amount FROM invoice WHERE InvoiceId = @Invoice_Id LIMIT 1); - Not working
SELECT  Amount INTO @myamount FROM invoice WHERE InvoiceId = 29  LIMIT 1; - Not working

If I run these queries directly then works, but not working in stored procedure.

Disable the postback on an <ASP:LinkButton>

ASPX code:

<asp:LinkButton ID="someID" runat="server" Text="clicky"></asp:LinkButton>

Code behind:

public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
        someID.Attributes.Add("onClick", "return false;");
    }
}

What renders as HTML is:

<a onclick="return false;" id="someID" href="javascript:__doPostBack('someID','')">clicky</a>

In this case, what happens is the onclick functionality becomes your validator. If it is false, the "href" link is not executed; however, if it is true the href will get executed. This eliminates your post back.

How to write a Unit Test?

Like @CoolBeans mentioned, take a look at jUnit. Here is a short tutorial to get you started as well with jUnit 4.x

Finally, if you really want to learn more about testing and test-driven development (TDD) I recommend you take a look at the following book by Kent Beck: Test-Driven Development By Example.

Swift how to sort array of custom objects by property value

If you want to sort original array of custom objects. Here is another way to do so in Swift 2.1

var myCustomerArray = [Customer]()
myCustomerArray.sortInPlace {(customer1:Customer, customer2:Customer) -> Bool in
    customer1.id < customer2.id
}

Where id is an Integer. You can use the same < operator for String properties as well.

You can learn more about its use by looking at an example here: Swift2: Nearby Customers

How to switch to new window in Selenium for Python?

On top of the answers already given, to open a new tab the javascript command window.open() can be used.

For example:

# Opens a new tab
self.driver.execute_script("window.open()")

# Switch to the newly opened tab
self.driver.switch_to.window(self.driver.window_handles[1])

# Navigate to new URL in new tab
self.driver.get("https://google.com")
# Run other commands in the new tab here

You're then able to close the original tab as follows

# Switch to original tab
self.driver.switch_to.window(self.driver.window_handles[0])

# Close original tab
self.driver.close()

# Switch back to newly opened tab, which is now in position 0
self.driver.switch_to.window(self.driver.window_handles[0])

Or close the newly opened tab

# Close current tab
self.driver.close()

# Switch back to original tab
self.driver.switch_to.window(self.driver.window_handles[0])

Hope this helps.

How to delete a stash created with git stash create?

It also works

git stash drop <index>

git stash drop 5

How to fix git error: RPC failed; curl 56 GnuTLS

Reinstalling git will solve the problem.

sudo apt-get remove git
sudo apt-get update
sudo apt-get install git

Class has no objects member

How about suppressing errors on each line specific to each error?

Something like this: https://pylint.readthedocs.io/en/latest/user_guide/message-control.html

Error: [pylint] Class 'class_name' has no 'member_name' member It can be suppressed on that line by:

  # pylint: disable=no-member

"document.getElementByClass is not a function"

It should be getElementsByClassName, and not getElementByClass. See this - https://developer.mozilla.org/en/DOM/document.getElementsByClassName.

Note that some browsers/versions may not support this.

The specified type member 'Date' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties

Simplified:

DateTime time = System.DateTime.Now;
ModelName m = context.TableName.Where(x=> DbFunctions.TruncateTime(x.Date) == time.Date)).FirstOrDefault();

No provider for TemplateRef! (NgIf ->TemplateRef)

You missed the * in front of NgIf (like we all have, dozens of times):

<div *ngIf="answer.accepted">&#10004;</div>

Without the *, Angular sees that the ngIf directive is being applied to the div element, but since there is no * or <template> tag, it is unable to locate a template, hence the error.

If you get this error with Angular v5:

Error: StaticInjectorError[TemplateRef]:
StaticInjectorError[TemplateRef]:
NullInjectorError: No provider for TemplateRef!

You may have <template>...</template> in one or more of your component templates. Change/update the tag to <ng-template>...</ng-template>.

T-SQL CASE Clause: How to specify WHEN NULL

Jason caught an error, so this works...

Can anyone confirm the other platform versions?
SQL Server:

SELECT
CASE LEN(ISNULL(last_name,'')) 
WHEN 0 THEN '' 
ELSE ' ' + last_name
END AS newlastName

MySQL:

SELECT
CASE LENGTH(IFNULL(last_name,'')) 
WHEN 0 THEN '' 
ELSE ' ' + last_name
END AS newlastName

Oracle:

SELECT
CASE LENGTH(NVL(last_name,'')) 
WHEN 0 THEN '' 
ELSE ' ' + last_name
END AS newlastName

MySQL: Insert record if not exists in table

I had a problem, and the method Mike advised worked partly, I had an error Dublicate Column name = '0', and changed the syntax of your query as this`

     $tQ = "INSERT  INTO names (name_id, surname_id, sum, sum2, sum3,sum4,sum5) 
                SELECT '$name', '$surname', '$sum', '$sum2', '$sum3','$sum4','$sum5' 
FROM DUAL
                WHERE NOT EXISTS (
                SELECT sum FROM names WHERE name_id = '$name' 
AND surname_id = '$surname') LIMIT 1;";

The problem was with column names. sum3 was equal to sum4 and mysql throwed dublicate column names, and I wrote the code in this syntax and it worked perfectly,

REST API - file (ie images) processing - best practices

There's no easy solution. Each way has their pros and cons . But the canonical way is using the first option: multipart/form-data. As W3 recommendation guide says

The content type "multipart/form-data" should be used for submitting forms that contain files, non-ASCII data, and binary data.

We aren't sending forms,really, but the implicit principle still applies. Using base64 as a binary representation, is incorrect because you're using the incorrect tool for accomplish your goal, in other hand, the second option forces your API clients to do more job in order to consume your API service. You should do the hard work in the server side in order to supply an easy-to-consume API. The first option is not easy to debug, but when you do it, it probably never changes.

Using multipart/form-data you're sticked with the REST/http philosophy. You can view an answer to similar question here.

Another option if mixing the alternatives, you can use multipart/form-data but instead of send every value separate, you can send a value named payload with the json payload inside it. (I tried this approach using ASP.NET WebAPI 2 and works fine).

Wait for Angular 2 to load/resolve model before rendering view/template

Set a local value with the observer

...also, don't forget to initialize the value with dummy data to avoid uninitialized errors.

export class ModelService {
    constructor() {
      this.mode = new Model();

      this._http.get('/api/v1/cats')
      .map(res => res.json())
      .subscribe(
        json => {
          this.model = new Model(json);
        },
        error => console.log(error);
      );
    }
}

This assumes Model, is a data model representing the structure of your data.

Model with no parameters should create a new instance with all values initialized (but empty). That way, if the template renders before the data is received it won't throw an error.

Ideally, if you want to persist the data to avoid unnecessary http requests you should put this in an object that has its own observer that you can subscribe to.

'nuget' is not recognized but other nuget commands working

You can also try setting the system variable path to the location of your nuget exe and restarting VS.

Open your system PATH variable and add the location of your nuget.exe (for me this is: C:\Program Files (x86)\NuGet\Visual Studio 2013)
Restart Visual Studio

I would have posted this as a comment to your answer @done_merson but I didn't have the required reputation to do that.

How to call a Parent Class's method from Child Class in Python?

class a(object):
    def my_hello(self):
        print "hello ravi"

class b(a):
    def my_hello(self):
    super(b,self).my_hello()
    print "hi"

obj = b()
obj.my_hello()

What exceptions should be thrown for invalid or unexpected parameters in .NET?

Short answer:
Neither

Longer answer:
using Argument*Exception (except in a library that is a product on its on, such as component library) is a smell. Exceptions are to handle exceptional situation, not bugs, and not user's (i.e. API consumer) shortfalls.

Longest answer:
Throwing exceptions for invalid arguments is rude, unless you write a library.
I prefer using assertions, for two (or more) reasons:

Assertions don't need to be tested, while throw assertions do, and test against ArgumentNullException looks ridiculous (try it).
Assertions better communicate the intended use of the unit, and is closer to being executable documentation than a class behavior specification.
You can change behavior of assertion violation. For example in debug compilation a message box is fine, so that your QA will hit you with it right away (you also get your IDE breaking on the line where it happens), while in unit test you can indicate assertion failure as a test failure.

Here is what handling of null exception looks like (being sarcastic, obviously):

try {
    library.Method(null);
}
catch (ArgumentNullException e) {
    // retry with real argument this time
    library.Method(realArgument);
}

Exceptions shall be used when situation is expected but exceptional (things happen that are outside of consumer's control, such as IO failure). Argument*Exception is an indication of a bug and shall be (my opinion) handled with tests and assisted with Debug.Assert

BTW: In this particular case, you could have used Month type, instead of int. C# falls short when it comes to type safety (Aspect# rulez!) but sometimes you can prevent (or catch at compile time) those bugs all together.

And yes, MicroSoft is wrong about that.

How can I get the current page's full URL on a Windows/IIS server?

Maybe, because you are under IIS,

$_SERVER['PATH_INFO']

is what you want, based on the URLs you used to explain.

For Apache, you'd use $_SERVER['REQUEST_URI'].

How to create a temporary directory/folder in Java?

Well, "createTempFile" actually creates the file. So why not just delete it first, and then do the mkdir on it?

PHP function to generate v4 UUID

How about using mysql to generate the uuid for you?

$conn = new mysqli($servername, $username, $password, $dbname, $port);

$query = 'SELECT UUID()';
echo $conn->query($query)->fetch_row()[0];

Recommended add-ons/plugins for Microsoft Visual Studio

I just found this rather large list of addins:

http://geekswithblogs.net/brians/archive/2008/05/12/122087.aspx

How to use Apple's new San Francisco font on a webpage

Last tested in 2015

Should use this solution as a last choice, when other solutions don't work.

Original answer:

Work on macOS Chrome/Safari

body { font-family: '.SFNSDisplay-Regular', sans-serif; }

How to break out from a ruby block?

next and break seem to do the correct thing in this simplified example!

class Bar
  def self.do_things
      Foo.some_method(1..10) do |x|
            next if x == 2
            break if x == 9
            print "#{x} "
      end
  end
end

class Foo
    def self.some_method(targets, &block)
      targets.each do |target|
        begin
          r = yield(target)
        rescue  => x
          puts "rescue #{x}"
        end
     end
   end
end

Bar.do_things

output: 1 3 4 5 6 7 8

using setTimeout on promise chain

The shorter ES6 version of the answer:

const delay = t => new Promise(resolve => setTimeout(resolve, t));

And then you can do:

delay(3000).then(() => console.log('Hello'));

How to debug in Android Studio using adb over WiFi

In Android Studio 3.0.1 > Goto > (Short cut key (Alt+Cltr+S)) Settings > Goto Plugins > Click on Browser repositories... > Search "ADB WIFI" and install the plugin. After the installation restart your android studio.

Click the icon and connect your device.

How to have image and text side by side

You're already doing it correctly, it just that the <h4>Facebook</h4> tag is taking too much vertical margin. You can remove it by using the style margin:0px on the <h4> tag.

For your future convenience, you can put border (border:1px solid black) on your elements to see which part you actually get it wrong.

How to avoid "Permission denied" when using pip with virtualenv

You did not activate the virtual environment before using pip.

Try it with:

$(your venv path) . bin/activate

And then use pip -r requirements.txt on your main folder

How to get rid of punctuation using NLTK tokenizer?

I think you need some sort of regular expression matching (the following code is in Python 3):

import string
import re
import nltk

s = "I can't do this now, because I'm so tired.  Please give me some time."
l = nltk.word_tokenize(s)
ll = [x for x in l if not re.fullmatch('[' + string.punctuation + ']+', x)]
print(l)
print(ll)

Output:

['I', 'ca', "n't", 'do', 'this', 'now', ',', 'because', 'I', "'m", 'so', 'tired', '.', 'Please', 'give', 'me', 'some', 'time', '.']
['I', 'ca', "n't", 'do', 'this', 'now', 'because', 'I', "'m", 'so', 'tired', 'Please', 'give', 'me', 'some', 'time']

Should work well in most cases since it removes punctuation while preserving tokens like "n't", which can't be obtained from regex tokenizers such as wordpunct_tokenize.

Refresh certain row of UITableView based on Int in Swift

How about:

self.tableView.reloadRowsAtIndexPaths([NSIndexPath(rowNumber)], withRowAnimation: UITableViewRowAnimation.Top)

ORA-00932: inconsistent datatypes: expected - got CLOB

The same error occurs also when doing SELECT DISTINCT ..., <CLOB_column>, ....

If this CLOB column contains values shorter than limit for VARCHAR2 in all the applicable rows you may use to_char(<CLOB_column>) or concatenate results of multiple calls to DBMS_LOB.SUBSTR(<CLOB_column>, ...).

Why are arrays of references illegal?

You can get fairly close with this template struct. However, you need to initialize with expressions that are pointers to T, rather than T; and so, though you can easily make a 'fake_constref_array' similarly, you won't be able to bind that to rvalues as done in the OP's example ('8');

#include <stdio.h>

template<class T, int N> 
struct fake_ref_array {
   T * ptrs[N];
  T & operator [] ( int i ){ return *ptrs[i]; }
};

int A,B,X[3];

void func( int j, int k)
{
  fake_ref_array<int,3> refarr = { &A, &B, &X[1] };
  refarr[j] = k;  // :-) 
   // You could probably make the following work using an overload of + that returns
   // a proxy that overloads *. Still not a real array though, so it would just be
   // stunt programming at that point.
   // *(refarr + j) = k  
}

int
main()
{
    func(1,7);  //B = 7
    func(2,8);     // X[1] = 8
    printf("A=%d B=%d X = {%d,%d,%d}\n", A,B,X[0],X[1],X[2]);
        return 0;
}

--> A=0 B=7 X = {0,8,0}

SPAN vs DIV (inline-block)

According to the HTML spec, <span> is an inline element and <div> is a block element. Now that can be changed using the display CSS property but there is one issue: in terms of HTML validation, you can't put block elements inside inline elements so:

<p>...<div>foo</div>...</p>

is not strictly valid even if you change the <div> to inline or inline-block.

So, if your element is inline or inline-block use a <span>. If it's a block level element, use a <div>.

What causes a TCP/IP reset (RST) flag to be sent?

RST is sent by the side doing the active close because it is the side which sends the last ACK. So if it receives FIN from the side doing the passive close in a wrong state, it sends a RST packet which indicates other side that an error has occured.

Border Height on CSS

table td {
    border-right:1px solid #000;
    height: 100%;
}

Just you add height under the border property.

adding to window.onload event?

If you are using jQuery, you don't have to do anything special. Handlers added via $(document).ready() don't overwrite each other, but rather execute in turn:

$(document).ready(func1)
...
$(document).ready(func2)

If you are not using jQuery, you could use addEventListener, as demonstrated by Karaxuna, plus attachEvent for IE<9.

Note that onload is not equivalent to $(document).ready() - the former waits for CSS, images... as well, while the latter waits for the DOM tree only. Modern browsers (and IE since IE9) support the DOMContentLoaded event on the document, which corresponds to the jQuery ready event, but IE<9 does not.

if(window.addEventListener){
  window.addEventListener('load', func1)
}else{
  window.attachEvent('onload', func1)
}
...
if(window.addEventListener){
  window.addEventListener('load', func2)
}else{
  window.attachEvent('onload', func2)
}

If neither option is available (for example, you are not dealing with DOM nodes), you can still do this (I am using onload as an example, but other options are available for onload):

var oldOnload1=window.onload;
window.onload=function(){
  oldOnload1 && oldOnload1();
  func1();
}
...
var oldOnload2=window.onload;
window.onload=function(){
  oldOnload2 && oldOnload2();
  func2();
}

or, to avoid polluting the global namespace (and likely encountering namespace collisions), using the import/export IIFE pattern:

window.onload=(function(oldLoad){
  return function(){
    oldLoad && oldLoad();
    func1();
  }
})(window.onload)
...
window.onload=(function(oldLoad){
  return function(){
    oldLoad && oldLoad();
    func2();
  }
})(window.onload)

How to convert NSNumber to NSString

You can do it with:

NSNumber *myNumber = @15;
NSString *myNumberInString = [myNumber stringValue];

How to hide html source & disable right click and text copy?

I think, here, right click is not mentioned, @Jishnu V S.

_x000D_

document.onkeydown = function(e) {
    if(e.keyCode == 123) {
     return false;
    }
    if(e.ctrlKey && e.shiftKey && e.keyCode == 'I'.charCodeAt(0)){
     return false;
    }
    if(e.ctrlKey && e.shiftKey && e.keyCode == 'J'.charCodeAt(0)){
     return false;
    }
    if(e.ctrlKey && e.keyCode == 'U'.charCodeAt(0)){
     return false;
    }

    if(e.ctrlKey && e.shiftKey && e.keyCode == 'C'.charCodeAt(0)){
     return false;
    }      
 }

_x000D_

How to properly seed random number generator

OK why so complex!

package main

import (
    "fmt"
    "math/rand"
    "time"
)

func main() {
    rand.Seed( time.Now().UnixNano())
    var bytes int

    for i:= 0 ; i < 10 ; i++{ 
        bytes = rand.Intn(6)+1
        fmt.Println(bytes)
        }
    //fmt.Println(time.Now().UnixNano())
}

This is based off the dystroy's code but fitted for my needs.

It's die six (rands ints 1 =< i =< 6)

func randomInt (min int , max int  ) int {
    var bytes int
    bytes = min + rand.Intn(max)
    return int(bytes)
}

The function above is the exactly same thing.

I hope this information was of use.

Pandas: Return Hour from Datetime Column Directly

Since the quickest, shortest answer is in a comment (from Jeff) and has a typo, here it is corrected and in full:

sales['time_hour'] = pd.DatetimeIndex(sales['timestamp']).hour

C# constructors overloading

public Point2D(Point2D point) : this(point.X, point.Y) { }

Laravel Eloquent update just if changes have been made

I like to add this method, if you are using an edit form, you can use this code to save the changes in your update(Request $request, $id) function:

$post = Post::find($id);    
$post->fill($request->input())->save();

keep in mind that you have to name your inputs with the same column name. The fill() function will do all the work for you :)

If else in stored procedure sql server

You can try below Procedure Sql:

Create Procedure sp_ADD_USER_EXTRANET_CLIENT_INDEX_PHY
(
@ParLngId int output
)
as
Begin
    -- Min will return only 1 value, if 'Extranet Client' is found
    -- IsNull will take care of 'Extranet Client' not found, returning 0 instead of Null
    -- But T_Param must be a Master Table with ParStrNom having a Unique Index, if so Min is not reqd at all
    -- But 'PHY', 'Extranet Client' suggests that Unique Key has 2 columns, not just ParStrNom

    SET @ParLngId = IsNull((Select Min (ParLngId) from T_Param where ParStrNom = 'Extranet Client'), 0);

    -- Nothing changed below

    if  (@ParLngId = 0)
        Begin
            Insert Into T_Param values ('PHY', 'Extranet Client', Null, Null, 'T', 0, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 1, NULL, NULL, NULL)
            SET @ParLngId = @@IDENTITY
    End

    Return  @ParLngId
    End

What strategies and tools are useful for finding memory leaks in .NET?

Big guns - Debugging Tools for Windows

This is an amazing collection of tools. You can analyze both managed and unmanaged heaps with it and you can do it offline. This was very handy for debugging one of our ASP.NET applications that kept recycling due to memory overuse. I only had to create a full memory dump of living process running on production server, all analysis was done offline in WinDbg. (It turned out some developer was overusing in-memory Session storage.)

"If broken it is..." blog has very useful articles on the subject.

Automate scp file transfer using a shell script

What about wildcards or multiple files?

scp file1 file2 more-files* user@remote:/some/dir/

Search for executable files using find command

find . -executable -type f

does not really guarantee that the file is executable it will find files with the execution bit set. If you do

chmod a+x image.jpg

the above find will think image.jpg is an executable even if it is really a jpeg image with the execution bit set.

I generally work around the issue with this:

find . -type f -executable -exec file {} \; | grep -wE "executable|shared object|ELF|script|a\.out|ASCII text"

If you want the find to actually print dome information about executable files you can do something like this:

find . -type f -executable -printf "%i.%D %s %m %U %G %C@ %p" 2>/dev/null |while read LINE
do
  NAME=$(awk '{print $NF}' <<< $LINE)
  file -b $NAME |grep -qEw "executable|shared object|ELF|script|a\.out|ASCII text" && echo $LINE
done

In the above example the file's full pathname is in the last field and must reflect where you look for it with awk "NAME=$(awk '{print $NF}' <<< $LINE)" if the file name was elsewhere in the find output string you need to replace "NF" with the correct numerical position. If your separator is not space you also need to tell awk what your separator is.

Where can I find the TypeScript version installed in Visual Studio?

The TypeScript team sorted this out in Visual Studio 2017 versions 15.3 and later, including the free Community edition.

How to See Which TypeScript Versions are Installed in Visual Studio

All you now need do is to go to project properties of any TypeScript Visual Studio project (right-click the project file in Solution Explorer/Properties), then go to the TypeScript Build tab on the left-hand side. This has a 'Typescript version' dropdown that shows you the version the project is using, and if you open it the dropdown shows you ALL versions of TypeScript currently installed in Visual Studio.

The actual installs are currently at C:\Program Files (x86)\Microsoft SDKs\TypeScript and then subfolders by version number, at least on Win10 on my computer. If you want to see the exact version (e.g. 2.8.3 rather than just 2.8) you can find the appropriate tsc.exe in here and look at its properties (Details tab in right-click/Properties in File Explorer).

How to Install Specific TypeScript Version

If you want to install a specific version of TypeScript for Visual Studio, you can download older versions from the Details->Releases section of the TypeScript SDK for Visual Studio 2017 Downloads page. You can verify that the version has been installed either with the 'Typescript version' dropdown in VS or inspecting the C:\Program Files (x86)\Microsoft SDKs\TypeScript folder.

Capitalize the first letter of both words in a two word string

Alternative:

library(stringr)
a = c("capitalise this", "and this")
a
[1] "capitalise this" "and this"       
str_to_title(a)
[1] "Capitalise This" "And This"

Where does Hive store files in HDFS?

The location they are stored on the HDFS is fairly easy to figure out once you know where to look. :)

If you go to http://NAMENODE_MACHINE_NAME:50070/ in your browser it should take you to a page with a Browse the filesystem link.

In the $HIVE_HOME/conf directory there is the hive-default.xml and/or hive-site.xml which has the hive.metastore.warehouse.dir property. That value is where you will want to navigate to after clicking the Browse the filesystem link.

In mine, it's /usr/hive/warehouse. Once I navigate to that location, I see the names of my tables. Clicking on a table name (which is just a folder) will then expose the partitions of the table. In my case, I currently only have it partitioned on date. When I click on the folder at this level, I will then see files (more partitioning will have more levels). These files are where the data is actually stored on the HDFS.

I have not attempted to access these files directly, I'm assuming it can be done. I would take GREAT care if you are thinking about editing them. :) For me - I'd figure out a way to do what I need to without direct access to the Hive data on the disk. If you need access to raw data, you can use a Hive query and output the result to a file. These will have the exact same structure (divider between columns, ect) as the files on the HDFS. I do queries like this all the time and convert them to CSVs.

The section about how to write data from queries to disk is https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DML#LanguageManualDML-Writingdataintothefilesystemfromqueries

UPDATE

Since Hadoop 3.0.0 - Alpha 1 there is a change in the default port numbers. NAMENODE_MACHINE_NAME:50070 changes to NAMENODE_MACHINE_NAME:9870. Use the latter if you are running on Hadoop 3.x. The full list of port changes are described in HDFS-9427

Python: count repeated elements in the list

This works for Python 2.6.6

a = ["a", "b", "a"]
result = dict((i, a.count(i)) for i in a)
print result

prints

{'a': 2, 'b': 1}

What's the UIScrollView contentInset property for?

Content insets solve the problem of having content that goes underneath other parts of the User Interface and yet still remains reachable using scroll bars. In other words, the purpose of the Content Inset is to make the interaction area smaller than its actual area.

Consider the case where we have three logical areas of the screen:

TOP BUTTONS

TEXT

BOTTOM TAB BAR

and we want the TEXT to never appear transparently underneath the TOP BUTTONS, but we want the Text to appear underneath the BOTTOM TAB BAR and yet still allow scrolling so we could update the text sitting transparently under the BOTTOM TAB BAR.

Then we would set the top origin to be below the TOP BUTTONS, and the height to include the bottom of BOTTOM TAB BAR. To gain access to the Text sitting underneath the BOTTOM TAB BAR content we would set the bottom inset to be the height of the BOTTOM TAB BAR.

Without the inset, the scroller would not let you scroll up the content enough to type into it. With the inset, it is as if the content had extra "BLANK CONTENT" the size of the content inset. Blank text has been "inset" into the real "content" -- that's how I remember the concept.

How to convert seconds to time format?

This might be simpler

gmdate("H:i:s", $seconds)

PHP gmdate

Replacing accented characters php

I found this way to be a good one, without having to worry too much about charsets and arrays, or iconv:

function replace_accents($str) {
   $str = htmlentities($str, ENT_COMPAT, "UTF-8");
   $str = preg_replace('/&([a-zA-Z])(uml|acute|grave|circ|tilde|ring);/','$1',$str);
   return html_entity_decode($str);
}

Git:nothing added to commit but untracked files present

You have two options here. You can either add the untracked files to your Git repository (as the warning message suggested), or you can add the files to your .gitignore file, if you want Git to ignore them.

To add the files use git add:

git add Optimization/language/languageUpdate.php
git add email_test.php

To ignore the files, add the following lines to your .gitignore:

/Optimization/language/languageUpdate.php
/email_test.php

Either option should allow the git pull to succeed afterwards.

how to increment integer Columns value by 1 in SQL

Sharing a variable between multiple different threads

Using static will not help your case.

Using synchronize locks a variable when it is in use by another thread.

You should use volatile keyword to keep the variable updated among all threads.

Using volatile is yet another way (like synchronized, atomic wrapper) of making class thread safe. Thread safe means that a method or class instance can be used by multiple threads at the same time without any problem.

How do I make a dictionary with multiple keys to one value?

If you're going to be adding to this dictionary frequently you'd want to take a class based approach, something similar to @Latty's answer in this SO question 2d-dictionary-with-many-keys-that-will-return-the-same-value.

However, if you have a static dictionary, and you need only access values by multiple keys then you could just go the very simple route of using two dictionaries. One to store the alias key association and one to store your actual data:

alias = {
    'a': 'id1',
    'b': 'id1',
    'c': 'id2',
    'd': 'id2'
}

dictionary = {
    'id1': 1,
    'id2': 2
}

dictionary[alias['a']]

If you need to add to the dictionary you could write a function like this for using both dictionaries:

def add(key, id, value=None)
    if id in dictionary:
        if key in alias:
            # Do nothing
            pass
        else:
            alias[key] = id
    else:
        dictionary[id] = value
        alias[key] = id

add('e', 'id2')
add('f', 'id3', 3)

While this works, I think ultimately if you want to do something like this writing your own data structure is probably the way to go, though it could use a similar structure.

Which mime type should I use for mp3

I had a problem with mime types and where making tests for few file types. It looks like each browser sends it's variation of a mime type for a specific file. I was trying to upload mp3 and zip files with open source php class, that what I have found:

Firefox (mp3): audio/mpeg
Firefox (zip): application/zip
Chrome (mp3): audio/mp3
Chrome (zip): application/octet-stream
Opera (mp3): audio/mp3
Opera (zip): application/octet-stream
IE (mp3): audio/mpeg
IE (zip): application/x-zip-compressed

So if you need several file types to upload, you better make some tests so that every browser could upload a file and pass mime type check.

Calling remove in foreach loop in Java

It's better to use an Iterator when you want to remove element from a list

because the source code of remove is

if (numMoved > 0)
    System.arraycopy(elementData, index+1, elementData, index,
             numMoved);
elementData[--size] = null;

so ,if you remove an element from the list, the list will be restructure ,the other element's index will be changed, this can result something that you want to happened.

How to remove the arrow from a select element in Firefox

Unfortunately for you this is "something fancy". Normally it's not the web authors place to redesign form elements. Many browsers purposely don't let you style them, in order for the user to see the OS controls they are used to.

The only way to do this consistently over browsers and operating systems, is use JavaScript and replace the select elements with "DHTML" ones.

Following article show three jQuery based plugins that allow you to do that (it is a bit old, but I couldn't find anything current right now)

http://www.queness.com/post/204/25-jquery-plugins-that-enhance-and-beautify-html-form-elements#1

How to send a JSON object using html form data

HTML provides no way to generate JSON from form data.

If you really want to handle it from the client, then you would have to resort to using JavaScript to:

gather your data from the form via DOM
organise it in an object or array
generate JSON with JSON.stringify
POST it with XMLHttpRequest

You'd probably be better off sticking to application/x-www-form-urlencoded data and processing that on the server instead of JSON. Your form doesn't have any complicated hierarchy that would benefit from a JSON data structure.

Update in response to major rewrite of the question…

Your JS has no readystatechange handler, so you do nothing with the response
You trigger the JS when the submit button is clicked without cancelling the default behaviour. The browser will submit the form (in the regular way) as soon as the JS function is complete.

How do you print in Sublime Text 2

There is also the Simple Print package, which uses enscript to do the actual printing.

Similar to kenorb's answer, open the palette (ctrl/cmd+shift+p), "Install package", "Simple Print Function"

you MUST install enscript and here is how:

https://github.com/svenax/SublimePrint

Can I use an image from my local file system as background in HTML?

It seems you can provide just the local image name, assuming it is in the same folder...

It suffices like:

background-image: url("img1.png")

Node.js/Windows error: ENOENT, stat 'C:\Users\RT\AppData\Roaming\npm'

Install a stable version instead of the latest one, I have downgrade my version to node-v0.10.29-x86.msi from 'node-v0.10.33-x86.msi' and it is working well for me!

http://blog.nodejs.org/2014/06/16/node-v0-10-29-stable/

How to set time to 24 hour format in Calendar

I am using fullcalendar on my project recently, I don't know what exact view effect you want to achieve, in my project I want to change the event time view from 12h format from

to 24h format.

If this is the effect you want to achieve, the solution below might help:

set timeFormat: 'H:mm'

How to change target build on Android project?

Well I agree with Ryan Conrad on how to do it in eclipse, have you ensured you have changed your manifest.xml?

 <uses-sdk android:minSdkVersion="3" />
 <uses-sdk android:targetSdkVersion="8" />

Can we create an instance of an interface in Java?

You can never instantiate an interface in java. You can, however, refer to an object that implements an interface by the type of the interface. For example,

public interface A
{
}
public class B implements A
{
}

public static void main(String[] args)
{
    A test = new B();
    //A test = new A(); // wont compile
}

What you did above was create an Anonymous class that implements the interface. You are creating an Anonymous object, not an object of type interface Test.

How to create war files

If you are not sure what to do and are starting from scratch then Maven can help get you started.

By following the the below steps you can get a new war project setup perfectly in eclipse.

Download and install Maven
Go the command line run: mvn archetype:generate
Follow the prompted steps - choosing the simple java web project (18) and a suitable name.
When it is finished run: mvn eclipse:eclipse
Start Eclipse. Choose File -> Import -> Existing project. Select the directory where you ran the mvn goals.
That's it you should now have a very good start to a war project in eclipse
You can create the war itself by running mvn package or deploy it by setting up a server in eclipse and simply adding adding the project to the server.

As some others have said the downside of using maven is that you have to use the maven conventions. But I think if you are just starting out, learning the conventions is a good idea before you start making your own. There's nothing to stop you changing/refactoring to your own preferred method at a later point.

Hope this helps.

Find the division remainder of a number

You can find remainder using modulo operator Example

a=14
b=10
print(a%b)

It will print 4

TransactionRequiredException Executing an update/delete query

Just add @Transactional on method level or class level. When you are updating or deleting record/s you have to maintain persistence state of Transaction and @Transactional manages this.

and import org.springframework.transaction.annotation.Transactional;

PHP code to convert a MySQL query to CSV

An update to @jrgns (with some slight syntax differences) solution.

$result = mysql_query('SELECT * FROM `some_table`'); 
if (!$result) die('Couldn\'t fetch records'); 
$num_fields = mysql_num_fields($result); 
$headers = array(); 
for ($i = 0; $i < $num_fields; $i++) 
{     
       $headers[] = mysql_field_name($result , $i); 
} 
$fp = fopen('php://output', 'w'); 
if ($fp && $result) 
{     
       header('Content-Type: text/csv');
       header('Content-Disposition: attachment; filename="export.csv"');
       header('Pragma: no-cache');    
       header('Expires: 0');
       fputcsv($fp, $headers); 
       while ($row = mysql_fetch_row($result)) 
       {
          fputcsv($fp, array_values($row)); 
       }
die; 
}

Set up a scheduled job?

Brian Neal's suggestion of running management commands via cron works well, but if you're looking for something a little more robust (yet not as elaborate as Celery) I'd look into a library like Kronos:

# app/cron.py

import kronos

@kronos.register('0 * * * *')
def task():
    pass

Select first row in each GROUP BY group?

In Postgres you can use array_agg like this:

SELECT  customer,
        (array_agg(id ORDER BY total DESC))[1],
        max(total)
FROM purchases
GROUP BY customer

This will give you the id of each customer's largest purchase.

Some things to note:

array_agg is an aggregate function, so it works with GROUP BY.
array_agg lets you specify an ordering scoped to just itself, so it doesn't constrain the structure of the whole query. There is also syntax for how you sort NULLs, if you need to do something different from the default.
Once we build the array, we take the first element. (Postgres arrays are 1-indexed, not 0-indexed).
You could use array_agg in a similar way for your third output column, but max(total) is simpler.
Unlike DISTINCT ON, using array_agg lets you keep your GROUP BY, in case you want that for other reasons.

HTTP response code for POST when resource already exists

What about 208 - http://httpstatusdogs.com/208-already-reported ? Is that a option?

In my opinion, if the only thing is a repeat resource no error should be raised. After all, there is no error neither on the client or server sides.

ImportError: No module named 'selenium'

If pip isn’t already installed, then first try to bootstrap it from the standard library:

sudo python -m ensurepip --default-pip

Ensure pip, setuptools, and wheel are up to date

sudo python -m pip install --upgrade pip setuptools wheel

Now Install Selenium

sudo pip install selenium

Now run your runner.

Hope this helps. Happy Coding !!

How to recover Git objects damaged by hard disk failure?

Here are two functions that may help if your backup is corrupted, or you have a few partially corrupted backups as well (this may happen if you backup the corrupted objects).

Run both in the repo you're trying to recover.

Standard warning: only use if you're really desperate and you have backed up your (corrupted) repo. This might not resolve anything, but at least should highlight the level of corruption.

fsck_rm_corrupted() {
    corrupted='a'
    while [ "$corrupted" ]; do
        corrupted=$(                                  \
        git fsck --full --no-dangling 2>&1 >/dev/null \
            | grep 'stored in'                          \
            | sed -r 's:.*(\.git/.*)\).*:\1:'           \
        )
        echo "$corrupted"
        rm -f "$corrupted"
    done
}

if [ -z "$1" ]  || [ ! -d "$1" ]; then
    echo "'$1' is not a directory. Please provide the directory of the git repo"
    exit 1
fi

pushd "$1" >/dev/null
fsck_rm_corrupted
popd >/dev/null

and

unpack_rm_corrupted() {
    corrupted='a'
    while [ "$corrupted" ]; do
        corrupted=$(                                  \
        git unpack-objects -r < "$1" 2>&1 >/dev/null \
            | grep 'stored in'                          \
            | sed -r 's:.*(\.git/.*)\).*:\1:'           \
        )
        echo "$corrupted"
        rm -f "$corrupted"
    done
}

if [ -z "$1" ]  || [ ! -d "$1" ]; then
    echo "'$1' is not a directory. Please provide the directory of the git repo"
    exit 1
fi

for p in $1/objects/pack/pack-*.pack; do
    echo "$p"
    unpack_rm_corrupted "$p"
done

Unable to access JSON property with "-" dash

For ansible, and using hyphen, this worked for me:

    - name: free-ud-ssd-space-in-percent
      debug:
        var: clusterInfo.json.content["free-ud-ssd-space-in-percent"]

vertical-align: middle with Bootstrap 2

Try this:

.row > .span3 {
    display: inline-block !important;
    vertical-align: middle !important;
}

Edit:

Fiddle: http://jsfiddle.net/EexYE/

You may need to add Diego's float: none !important; also if span3 is floating and it interferes.

Edit:

Fiddle: http://jsfiddle.net/D8McR/

In response to Alberto: if you fix the height of the row div, then to continue the vertical center alignment you'll need to set the line-height of the row to be the same as the pixel height of the row (ie. both to 300px in your case). If you'll do that you will notice that the child elements inherit the line-height, which is a problem in this case, so you will then need to set your line height for the span3s to whatever it should actually be (1.5 is the example value in the fiddle, or 1.5 x the font-size, which we did not change when we changed the line-height).

Binary numbers in Python

You can convert between a string representation of the binary using bin() and int()

>>> bin(88)
'0b1011000'
>>> int('0b1011000', 2)
88
>>> 

>>> a=int('01100000', 2)
>>> b=int('00100110', 2)
>>> bin(a & b)
'0b100000'
>>> bin(a | b)
'0b1100110'
>>> bin(a ^ b)
'0b1000110'

Connecting PostgreSQL 9.2.1 with Hibernate

If the project is maven placed it in src/main/resources, in the package phase it will copy it in ../WEB-INF/classes/hibernate.cfg.xml

Using custom fonts using CSS?

there's also an interesting tool called CUFON. There's a demonstration of how to use it in this blog It's really simple and interesting. Also, it doesn't allow people to ctrl+c/ctrl+v the generated content.

How do I embed a mp4 movie into my html?

If you have an mp4 video residing at your server, and you want the visitors to stream that over your HTML page.

<video width="480" height="320" controls="controls">
<source src="http://serverIP_or_domain/location_of_video.mp4" type="video/mp4">
</video>

How do I pretty-print existing JSON data with Java?

Use gson. https://www.mkyong.com/java/how-to-enable-pretty-print-json-output-gson/

Gson gson = new GsonBuilder().setPrettyPrinting().create();
String json = gson.toJson(my_bean);

output

{
  "name": "mkyong",
  "age": 35,
  "position": "Founder",
  "salary": 10000,
  "skills": [
    "java",
    "python",
    "shell"
  ]
}

How do I calculate square root in Python?

If you want to do it the way the calculator actually does it, use the Babylonian technique. It is explained here and here.

Suppose you want to calculate the square root of 2:

a=2

a1 = (a/2)+1
b1 = a/a1
aminus1 = a1
bminus1 = b1


while (aminus1-bminus1 > 0):
    an = 0.5 * (aminus1 + bminus1)
    bn = a / an
    aminus1 = an
    bminus1 = bn
    print(an,bn,an-bn)

How to sort a list/tuple of lists/tuples by the element at a given index?

Without lambda:

def sec_elem(s):
    return s[1]

sorted(data, key=sec_elem)

Running PowerShell as another user, and launching a script

In windows server 2012 or 2016 you can search for Windows PowerShell and then "Pin to Start". After this you will see "Run as different user" option on a right click on the start page tiles.

Ruby Arrays: select(), collect(), and map()

EDIT: I just realized you want to filter details, which is an array of hashes. In that case you could do

details.reject { |item| item[:qty].empty? }

The inner data structure itself is not an Array, but a Hash. You can also use select here, but the block is given the key and value in this case:

irb(main):001:0> h = {:sku=>"507772-B21", :desc=>"HP 1TB 3G SATA 7.2K RPM LFF (3 .", :qty=>"", :qty2=>"1", :price=>"5,204.34 P"}
irb(main):002:0> h.select { |key, value| !value.empty? }
=> {:sku=>"507772-B21", :desc=>"HP 1TB 3G SATA 7.2K RPM LFF (3 .", 
    :qty2=>"1", :price=>"5,204.34 P"}

Or using reject, which is the inverse of select (excludes all items for which the given condition holds):

h.reject { |key, value| value.empty? }

Note that this is Ruby 1.9. If you have to maintain compatibility with 1.8, you could do:

Hash[h.reject { |key, value| value.empty? }]

Capturing a form submit with jquery and .submit

Just replace the form.submit function with your own implementation:

var form = document.getElementById('form');
var formSubmit = form.submit; //save reference to original submit function

form.onsubmit = function(e)
{
    formHandler();
    return false;
};

var formHandler = form.submit = function()
{
    alert('hi there');
    formSubmit(); //optionally submit the form
};

Finding the second highest number in array

public class SecondHighInIntArray {

public static void main(String[] args) {
    int[] intArray=new int[]{2,2,1};
            //{2,2,1,12,3,7,9,-1,-5,7};
    int secHigh=findSecHigh(intArray);
    System.out.println(secHigh);
}

private static int findSecHigh(int[] intArray) {

    int highest=Integer.MIN_VALUE;
    int sechighest=Integer.MIN_VALUE;
    int len=intArray.length;
    for(int i=0;i<len;i++)
    {
        if(intArray[i]>highest)
        {
            sechighest=highest;
            highest=intArray[i];
            continue;
        }

        if(intArray[i]<highest && intArray[i]>sechighest)
        {
            sechighest=intArray[i];
            continue;
        }


    }
    return sechighest;
}

}

Could not locate Gemfile

I had the same problem and got it solved by using a different directory.

bash-4.2$ bundle install
Could not locate Gemfile
bash-4.2$ pwd
/home/amit/redmine/redmine-2.2.2-0/apps/redmine
bash-4.2$ cd htdocs/
bash-4.2$ ls
app  config db   extra  Gemfile   lib  plugins  Rakefile     script  tmp
bin  config.ru  doc  files  Gemfile.lock  log  public   README.rdoc  test    vendor
bash-4.2$ cd plugins/
bash-4.2$ bundle install
Using rake (0.9.2.2) 
Using i18n (0.6.0) 
Using multi_json (1.3.6) 
Using activesupport (3.2.11) 
Using builder (3.0.0) 
Using activemodel (3.2.11) 
Using erubis (2.7.0) 
Using journey (1.0.4) 
Using rack (1.4.1) 
Using rack-cache (1.2) 
Using rack-test (0.6.1) 
Using hike (1.2.1) 
Using tilt (1.3.3) 
Using sprockets (2.2.1) 
Using actionpack (3.2.11) 
Using mime-types (1.19) 
Using polyglot (0.3.3) 
Using treetop (1.4.10) 
Using mail (2.4.4) 
Using actionmailer (3.2.11) 
Using arel (3.0.2) 
Using tzinfo (0.3.33) 
Using activerecord (3.2.11) 
Using activeresource (3.2.11) 
Using coderay (1.0.6) 
Using rack-ssl (1.3.2) 
Using json (1.7.5) 
Using rdoc (3.12) 
Using thor (0.15.4) 
Using railties (3.2.11) 
Using jquery-rails (2.0.3) 
Using mysql2 (0.3.11) 
Using net-ldap (0.3.1) 
Using ruby-openid (2.1.8) 
Using rack-openid (1.3.1) 
Using bundler (1.2.3) 
Using rails (3.2.11) 
Using rmagick (2.13.1) 
Your bundle i

How can I determine installed SQL Server instances and their versions?

I had this same issue when I was assessing 100+ servers, I had a script written in C# to browse the service names consist of SQL. When instances installed on the server, SQL Server adds a service for each instance with service name. It may vary for different versions like 2000 to 2008 but for sure there is a service with instance name.

I take the service name and obtain instance name from the service name. Here is the sample code used with WMI Query Result:

if (ServiceData.DisplayName == "MSSQLSERVER" || ServiceData.DisplayName == "SQL Server (MSSQLSERVER)")
            {
                InstanceData.Name = "DEFAULT";
                InstanceData.ConnectionName = CurrentMachine.Name;
                CurrentMachine.ListOfInstances.Add(InstanceData);
            }
            else
                if (ServiceData.DisplayName.Contains("SQL Server (") == true)
                {
                    InstanceData.Name = ServiceData.DisplayName.Substring(
                                            ServiceData.DisplayName.IndexOf("(") + 1,
                                            ServiceData.DisplayName.IndexOf(")") - ServiceData.DisplayName.IndexOf("(") - 1
                                        );
                    InstanceData.ConnectionName = CurrentMachine.Name + "\\" + InstanceData.Name;
                    CurrentMachine.ListOfInstances.Add(InstanceData);
                }
                else
                    if (ServiceData.DisplayName.Contains("MSSQL$") == true)
                    {
                        InstanceData.Name = ServiceData.DisplayName.Substring(
                                                ServiceData.DisplayName.IndexOf("$") + 1,
                                                ServiceData.DisplayName.Length - ServiceData.DisplayName.IndexOf("$") - 1
                                            );

                        InstanceData.ConnectionName = CurrentMachine.Name + "\\" + InstanceData.Name;
                        CurrentMachine.ListOfInstances.Add(InstanceData);
                    }

C#, Looping through dataset and show each record from a dataset column

foreach (DataRow dr in ds.Tables[0].Rows)
{
    //your code here
}

Repeat String - Javascript

Concatenating strings based on an number.

function concatStr(str, num) {
   var arr = [];

   //Construct an array
   for (var i = 0; i < num; i++)
      arr[i] = str;

   //Join all elements
   str = arr.join('');

   return str;
}

console.log(concatStr("abc", 3));

Hope that helps!

How to convert a Collection to List?

Collections.sort( new ArrayList( coll ) );

How to zip a whole folder using PHP

Create a zip folder in PHP.

Zip create method

   public function zip_creation($source, $destination){
    $dir = opendir($source);
    $result = ($dir === false ? false : true);

    if ($result !== false) {

        
        $rootPath = realpath($source);
         
        // Initialize archive object
        $zip = new ZipArchive();
        $zipfilename = $destination.".zip";
        $zip->open($zipfilename, ZipArchive::CREATE | ZipArchive::OVERWRITE );
         
        // Create recursive directory iterator
        /** @var SplFileInfo[] $files */
        $files = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($rootPath), RecursiveIteratorIterator::LEAVES_ONLY);
         
        foreach ($files as $name => $file)
        {
            // Skip directories (they would be added automatically)
            if (!$file->isDir())
            {
                // Get real and relative path for current file
                $filePath = $file->getRealPath();
                $relativePath = substr($filePath, strlen($rootPath) + 1);
         
                // Add current file to archive
                $zip->addFile($filePath, $relativePath);
            }
        }
         
        // Zip archive will be created only after closing object
        $zip->close();
        
        return TRUE;
    } else {
        return FALSE;
    }


}

Call the zip method

$source = $source_directory;
$destination = $destination_directory;
$zipcreation = $this->zip_creation($source, $destination);

How to pass a parameter to Vue @click event handler

I had the same issue and here is how I manage to pass through:

In your case you have addToCount() which is called. now to pass down a param when user clicks, you can say @click="addToCount(item.contactID)"

in your function implementation you can receive the params like:

addToCount(paramContactID){
 // the paramContactID contains the value you passed into the function when you called it
 // you can do what you want to do with the paramContactID in here!

}

How to add element into ArrayList in HashMap

Typical code is to create an explicit method to add to the list, and create the ArrayList on the fly when adding. Note the synchronization so the list only gets created once!

@Override
public synchronized boolean addToList(String key, Item item) {
   Collection<Item> list = theMap.get(key);
   if (list == null)  {
      list = new ArrayList<Item>();  // or, if you prefer, some other List, a Set, etc...
      theMap.put(key, list );
   }

   return list.add(item);
}

Why is the minidlna database not being refreshed?

AzP already provided most of the information, but some of it is incorrect.

First of all, there is no such option inotify_interval. The only option that exists is notify_interval and has nothing to do with inotify.

So to clarify, notify_interval controls how frequently the (mini)dlna server announces itself in the network. The default value of 895 means it will announce itself about once every 15 minutes, meaning clients will need at most 15 minutes to find the server. I personally use 1-5 minutes depending on client volatility in the network.

In terms of getting minidlna to find files that have been added, there are two options:

The first is equivalent to removing the file files.db and consists in restarting minidlna while passing the -R argument, which forces a full rescan and builds the database from scratch. Since version 1.2.0 there's now also the -r argument which performs a rebuild action. This preserves any existing database and drops and adds old and new records, respectively.
The second is to rely on inotify events by setting inotify=yes and restarting minidlna. If inotify is set to =no, the only option to update the file database is the forced full rescan.

Additionally, in order to have inotify working, the file-system must support inotify events, which is not the case in most remote file-systems. If you have minidlna running over NFS it will not see any inotify events because these are generated on the server side and not on the client.

Finally, even if inotify is working and is supported by the file-system, the user under which minidlna is running must be able to read the file, otherwise it will not be able to retrieve necessary metadata. In this case, the logfile (usually /var/log/minidlna.log) should contain useful information.

Custom thread pool in Java 8 parallel stream

you can try implementing this ForkJoinWorkerThreadFactory and inject it to Fork-Join class.

public ForkJoinPool(int parallelism,
                        ForkJoinWorkerThreadFactory factory,
                        UncaughtExceptionHandler handler,
                        boolean asyncMode) {
        this(checkParallelism(parallelism),
             checkFactory(factory),
             handler,
             asyncMode ? FIFO_QUEUE : LIFO_QUEUE,
             "ForkJoinPool-" + nextPoolId() + "-worker-");
        checkPermission();
    }

you can use this constructor of Fork-Join pool to do this.

notes:-- 1. if you use this, take into consideration that based on your implementation of new threads, scheduling from JVM will be affected, which generally schedules fork-join threads to different cores(treated as a computational thread). 2. task scheduling by fork-join to threads won't get affected. 3. Haven't really figured out how parallel stream is picking threads from fork-join(couldn't find proper documentation on it), so try using a different threadNaming factory so as to make sure, if threads in parallel stream are being picked from customThreadFactory that you provide. 4. commonThreadPool won't use this customThreadFactory.

How to flatten only some dimensions of a numpy array

A slight generalization to Alexander's answer - np.reshape can take -1 as an argument, meaning "total array size divided by product of all other listed dimensions":

e.g. to flatten all but the last dimension:

>>> arr = numpy.zeros((50,100,25))
>>> new_arr = arr.reshape(-1, arr.shape[-1])
>>> new_arr.shape
# (5000, 25)

Display the binary representation of a number in C?

#include<iostream>
#include<conio.h>
#include<stdlib.h>
using namespace std;
void displayBinary(int n)
{
       char bistr[1000];
       itoa(n,bistr,2);       //2 means binary u can convert n upto base 36
       printf("%s",bistr);

}

int main()
{
    int n;
    cin>>n;
    displayBinary(n);
    getch();
    return 0;
}

MySQL "Or" Condition

Use brackets to group the OR statements.

mysql_query("SELECT * FROM Drinks WHERE email='$Email' AND (date='$Date_Today' OR date='$Date_Yesterday' OR date='$Date_TwoDaysAgo' OR date='$Date_ThreeDaysAgo' OR date='$Date_FourDaysAgo' OR date='$Date_FiveDaysAgo' OR date='$Date_SixDaysAgo' OR date='$Date_SevenDaysAgo')");

You can also use IN

mysql_query("SELECT * FROM Drinks WHERE email='$Email' AND date IN ('$Date_Today','$Date_Yesterday','$Date_TwoDaysAgo','$Date_ThreeDaysAgo','$Date_FourDaysAgo','$Date_FiveDaysAgo','$Date_SixDaysAgo','$Date_SevenDaysAgo')");

How do I get the coordinates of a mouse click on a canvas element?

First, as others have said, you need a function to get the position of the canvas element. Here's a method that's a little more elegant than some of the others on this page (IMHO). You can pass it any element and get its position in the document:

function findPos(obj) {
    var curleft = 0, curtop = 0;
    if (obj.offsetParent) {
        do {
            curleft += obj.offsetLeft;
            curtop += obj.offsetTop;
        } while (obj = obj.offsetParent);
        return { x: curleft, y: curtop };
    }
    return undefined;
}

Now calculate the current position of the cursor relative to that:

$('#canvas').mousemove(function(e) {
    var pos = findPos(this);
    var x = e.pageX - pos.x;
    var y = e.pageY - pos.y;
    var coordinateDisplay = "x=" + x + ", y=" + y;
    writeCoordinateDisplay(coordinateDisplay);
});

Notice that I've separated the generic findPos function from the event handling code. (As it should be. We should try to keep our functions to one task each.)

The values of offsetLeft and offsetTop are relative to offsetParent, which could be some wrapper div node (or anything else, for that matter). When there is no element wrapping the canvas they're relative to the body, so there is no offset to subtract. This is why we need to determine the position of the canvas before we can do anything else.

Similary, e.pageX and e.pageY give the position of the cursor relative to the document. That's why we subtract the canvas's offset from those values to arrive at the true position.

An alternative for positioned elements is to directly use the values of e.layerX and e.layerY. This is less reliable than the method above for two reasons:

These values are also relative to the entire document when the event does not take place inside a positioned element
They are not part of any standard

How can I retrieve Id of inserted entity using Entity framework?

You can get ID only after saving, instead you can create a new Guid and assign before saving.

Windows command to convert Unix line endings?

try this:

(for /f "delims=" %i in (file.unix) do @echo %i)>file.dos

Session protocol:

C:\TEST>xxd -g1 file.unix
0000000: 36 31 36 38 39 36 32 39 33 30 38 31 30 38 36 35  6168962930810865
0000010: 0a 34 38 36 38 39 37 34 36 33 32 36 31 38 31 39  .486897463261819
0000020: 37 0a 37 32 30 30 31 33 37 33 39 31 39 32 38 35  7.72001373919285
0000030: 34 37 0a 35 30 32 32 38 31 35 37 33 32 30 32 30  47.5022815732020
0000040: 35 32 34 0a                                      524.

C:\TEST>(for /f "delims=" %i in (file.unix) do @echo %i)>file.dos

C:\TEST>xxd -g1 file.dos
0000000: 36 31 36 38 39 36 32 39 33 30 38 31 30 38 36 35  6168962930810865
0000010: 0d 0a 34 38 36 38 39 37 34 36 33 32 36 31 38 31  ..48689746326181
0000020: 39 37 0d 0a 37 32 30 30 31 33 37 33 39 31 39 32  97..720013739192
0000030: 38 35 34 37 0d 0a 35 30 32 32 38 31 35 37 33 32  8547..5022815732
0000040: 30 32 30 35 32 34 0d 0a                          020524..

ASP.NET Identity DbContext confusion

I would use a single Context class inheriting from IdentityDbContext. This way you can have the context be aware of any relations between your classes and the IdentityUser and Roles of the IdentityDbContext. There is very little overhead in the IdentityDbContext, it is basically a regular DbContext with two DbSets. One for the users and one for the roles.

X-Frame-Options on apache

This worked for me on all browsers:

Created one page with all my javascript
Created a 2nd page on the same server and embedded the first page using the object tag.
On my third party site I used the Object tag to embed the 2nd page.
Created a .htaccess file on the original server in the public_html folder and put Header unset X-Frame-Options in it.

MySQL: Enable LOAD DATA LOCAL INFILE

Ok, something odd is happening here. To make this work, do NOT need to make any configuration changes in /etc/mysql/my.cnf . All you need to do is to restart the current mysql service in terminal:

sudo service mysql restart

Then if I want to "recreate" the bug, I simply restart the apache service:

sudo service apache2 restart

Which can then be fixed again by entering the following command:

sudo service mysql restart

So, it appears that the apache2 is doing something to not allow this feature when it starts up (which is then reversed/corrected if restart the mysql service).

Valid in Debian based distributions.

service mysqld restart
service httpd restart

Valid in RedHat based distributions

How do I revert my changes to a git submodule?

If you want to discard all changes in the entire repository along with sub modules, you can use

git restore . --recurse-submodules

This will undo all changes made in repository and in sub modules.

How can I change or remove HTML5 form validation default error messages?

<input type="text" pattern="[a-zA-Z]+"
oninvalid="setCustomValidity('Plz enter on Alphabets ')" />

I found this code in another post.

Command not found when using sudo

The other solutions I've seen here so far are based on some system definitions, but it's in fact possible to have sudo use the current PATH (with the env command) and/or the rest of the environment (with the -E option) just by invoking it right:

sudo -E env "PATH=$PATH" <command> [arguments]

In fact, one can make an alias out of it:

alias mysudo='sudo -E env "PATH=$PATH"'

(It's also possible to name the alias itself sudo, replacing the original sudo.)

What is default session timeout in ASP.NET?

It depends on either the configuration or programmatic change.
Therefore the most reliable way to check the current value is at runtime via code.

See the HttpSessionState.Timeout property; default value is 20 minutes.

You can access this propery in ASP.NET via HttpContext:

this.HttpContext.Session.Timeout // ASP.NET MVC controller
Page.Session.Timeout // ASP.NET Web Forms code-behind
HttpContext.Current.Session.Timeout // Elsewhere

enum Values to NSString (iOS)

You could use X macros - they are perfect for this.

Benefits 1. the relationship between the actual enum value and the string value is in one place. 2. you can use regular switch statements later in your code.

Detriment 1. The initial setup code is a bit obtuse, and uses fun macros.

The code

#define X(a, b, c) a b,
enum ZZObjectType {
    ZZOBJECTTYPE_TABLE
};
typedef NSUInteger TPObjectType;
#undef X

#define XXOBJECTTYPE_TABLE \
X(ZZObjectTypeZero, = 0, "ZZObjectTypeZero") \
X(ZZObjectTypeOne, = 1, "ZZObjectTypeOne") \
X(ZZObjectTypeTwo, = 2, "ZZObjectTypeTwo") \
X(ZZObjectTypeThree, = 3, "ZZObjectTypeThree") \

+ (NSString*)nameForObjectType:(ZZObjectType)objectType {
#define X(a, b, c) @c, [NSNumber numberWithInteger:a],
    NSDictionary *returnValue = [NSDictionary dictionaryWithObjectsAndKeys:ZZOBJECTTYPE_TABLE nil];
#undef X
    return [returnValue objectForKey:[NSNumber numberWithInteger:objectType]];
}

+ (ZZObjectType)objectTypeForName:(NSString *)objectTypeString {
#define X(a, b, c) [NSNumber numberWithInteger:a], @c,
    NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:ZZOBJECTSOURCE_TABLE nil];
#undef X
    NSUInteger value = [(NSNumber *)[dictionary objectForKey:objectTypeString] intValue];
    return (ZZObjectType)value;
}

Now you can do:

NSString *someString = @"ZZObjectTypeTwo"
ZZObjectType objectType = [[XXObject objectTypeForName:someString] intValue];
switch (objectType) {
    case ZZObjectTypeZero:
        //
        break;
    case ZZObjectTypeOne:
        //
        break;
    case ZZObjectTypeTwo:
        //
        break;
}

This pattern has been around since the 1960's (no kidding!): http://en.wikipedia.org/wiki/X_Macro

Cannot read property 'length' of null (javascript)

The proper test is:

if (capital != null && capital.length < 1) {

This ensures that capital is always non null, when you perform the length check.

Also, as the comments suggest, capital is null because you never initialize it.

Is there a constraint that restricts my generic method to numeric types?

This limitation affected me when I tried to overload operators for generic types; since there was no "INumeric" constraint, and for a bevy of other reasons the good people on stackoverflow are happy to provide, operations cannot be defined on generic types.

I wanted something like

public struct Foo<T>
{
    public T Value{ get; private set; }

    public static Foo<T> operator +(Foo<T> LHS, Foo<T> RHS)
    {
        return new Foo<T> { Value = LHS.Value + RHS.Value; };
    }
}

I have worked around this issue using .net4 dynamic runtime typing.

public struct Foo<T>
{
    public T Value { get; private set; }

    public static Foo<T> operator +(Foo<T> LHS, Foo<T> RHS)
    {
        return new Foo<T> { Value = LHS.Value + (dynamic)RHS.Value };
    }
}

The two things about using dynamic are

Performance. All value types get boxed.
Runtime errors. You "beat" the compiler, but lose type safety. If the generic type doesn't have the operator defined, an exception will be thrown during execution.

How do I change a tab background color when using TabLayout?

Have you tried checking the API?

You will need to create a listener for the OnTabSelectedListener event, then when a user selects any tab you should check if it is the correct one, then change the background color using tabLayout.setBackgroundColor(int color), or if it is not the correct tab make sure you change back to the normal color again with the same method.

PHP: How to generate a random, unique, alphanumeric string for use in a secret link?

When trying to generate a random password you are trying to :

First generate a cryptographically secure set of random bytes
Second is turning those random bytes into a printable string

Now, there are multiple way to generate random bytes in php like :

$length = 32;

//PHP 7+
$bytes= random_bytes($length);

//PHP < 7
$bytes= openssl_random_pseudo_bytes($length);

Then you want to turn these random bytes into a printable string :

You can use bin2hex :

$string = bin2hex($bytes);

or base64_encode :

$string = base64_encode($bytes);

However, note that you do not control the length of the string if you use base64. You can use bin2hex to do that, using 32 bytes will turn into a 64 char string. But it will only work like so in an EVEN string.

So basically you can just do :

$length = 32;

if(PHP_VERSION>=7){
    $bytes= random_bytes($length);
}else{
    $bytes= openssl_random_pseudo_bytes($length);
} 

$string = bin2hex($bytes);

Count number of lines in a git repository

This tool on github https://github.com/flosse/sloc can give the output in more descriptive way. It will Create stats of your source code:

physical lines
lines of code (source)
lines with comments
single-line comments
lines with block comments
lines mixed up with source and comments
empty lines

Angular 2 change event - model changes

Use the (ngModelChange) event to detect changes on the model

Integer value in TextView

just found an advance and most currently used method to set string in textView

textView.setText(String.valueOf(YourIntegerNumber));

How do I get the base URL with PHP?

Try the following code :

$config['base_url'] = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == "on") ? "https" : "http");
$config['base_url'] .= "://".$_SERVER['HTTP_HOST'];
$config['base_url'] .= str_replace(basename($_SERVER['SCRIPT_NAME']),"",$_SERVER['SCRIPT_NAME']);
echo $config['base_url'];

How to remove/ignore :hover css style on touch devices

2020 Solution - CSS only - No Javascript

Use media hover with media pointer will help you guys resolve this issue. Tested on chrome Web and android mobile. I known this old question but I didn't find any solution like this.

_x000D_

@media (hover: hover) and (pointer: fine) {
  a:hover { color: red; }
}

_x000D_

<a href="#" >Some Link</a>

_x000D_

Sharing url link does not show thumbnail image on facebook

I ran into this and while I had the og:image (and others), I was missing og:url and og:type, so I added those and then it worked.

<meta property="og:url" content="<? 
 $url = 'https://' . $_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF']."?".$_SERVER['QUERY_STRING'];; 
echo htmlentities($url,ENT_QUOTES); ?>"/>

Number of processors/cores in command line

The lscpu(1) command provided by the util-linux project might also be useful:

$ lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                4
On-line CPU(s) list:   0-3
Thread(s) per core:    2
Core(s) per socket:    2
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 58
Model name:            Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz
Stepping:              9
CPU MHz:               3406.253
CPU max MHz:           3600.0000
CPU min MHz:           1200.0000
BogoMIPS:              5787.10
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              4096K
NUMA node0 CPU(s):     0-3

How do I calculate the percentage of a number?

Divide $percentage by 100 and multiply to $totalWidth. Simple maths.

How to pass a Javascript Array via JQuery Post so that all its contents are accessible via the PHP $_POST array?

Here it goes an example:

$.post("test.php", { 'choices[]': ["Jon", "Susan"] });

Hope it helps.

Is recursion ever faster than looping?

This depends on the language being used. You wrote 'language-agnostic', so I'll give some examples.

In Java, C, and Python, recursion is fairly expensive compared to iteration (in general) because it requires the allocation of a new stack frame. In some C compilers, one can use a compiler flag to eliminate this overhead, which transforms certain types of recursion (actually, certain types of tail calls) into jumps instead of function calls.

In functional programming language implementations, sometimes, iteration can be very expensive and recursion can be very cheap. In many, recursion is transformed into a simple jump, but changing the loop variable (which is mutable) sometimes requires some relatively heavy operations, especially on implementations which support multiple threads of execution. Mutation is expensive in some of these environments because of the interaction between the mutator and the garbage collector, if both might be running at the same time.

I know that in some Scheme implementations, recursion will generally be faster than looping.

In short, the answer depends on the code and the implementation. Use whatever style you prefer. If you're using a functional language, recursion might be faster. If you're using an imperative language, iteration is probably faster. In some environments, both methods will result in the same assembly being generated (put that in your pipe and smoke it).

Addendum: In some environments, the best alternative is neither recursion nor iteration but instead higher order functions. These include "map", "filter", and "reduce" (which is also called "fold"). Not only are these the preferred style, not only are they often cleaner, but in some environments these functions are the first (or only) to get a boost from automatic parallelization — so they can be significantly faster than either iteration or recursion. Data Parallel Haskell is an example of such an environment.

List comprehensions are another alternative, but these are usually just syntactic sugar for iteration, recursion, or higher order functions.

VB.net: Date without time

Either use one of the standard date and time format strings which only specifies the date (e.g. "D" or "d"), or a custom date and time format string which only uses the date parts (e.g. "yyyy/MM/dd").

Java swing application, close one window and open another when button is clicked

This is obviously the scenario where you should be using CardLayout. Here instead of opening two JFrame, what you can do is simply change the JPanels using CardLayout.

And the code that is responsible for creating and displaying your GUI should be inside the SwingUtilities.invokeLater(...); method for it to be Thread Safe. For More Info you have to read about Concurrency in Swing.

But if you want to stick to your approach, here is a Sample Code for your Help.

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class TwoFrames
{
    private JFrame frame1, frame2;
    private ActionListener action;
    private JButton showButton, hideButton;

    public void createAndDisplayGUI()
    {
        frame1 = new JFrame("FRAME 1");
        frame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);      
        frame1.setLocationByPlatform(true);

        JPanel contentPane1 = new JPanel();
        contentPane1.setBackground(Color.BLUE);

        showButton = new JButton("OPEN FRAME 2");
        hideButton = new JButton("HIDE FRAME 2");

        action  = new ActionListener()
        {
            public void actionPerformed(ActionEvent ae)
            {
                JButton button = (JButton) ae.getSource();

                /*
                 * If this button is clicked, we will create a new JFrame,
                 * and hide the previous one.
                 */
                if (button == showButton)
                {
                    frame2 = new JFrame("FRAME 2");
                    frame2.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);      
                    frame2.setLocationByPlatform(true);

                    JPanel contentPane2 = new JPanel();
                    contentPane2.setBackground(Color.DARK_GRAY);

                    contentPane2.add(hideButton);
                    frame2.getContentPane().add(contentPane2);
                    frame2.setSize(300, 300);
                    frame2.setVisible(true);
                    frame1.setVisible(false);
                }
                /*
                 * Here we will dispose the previous frame, 
                 * show the previous JFrame.
                 */
                else if (button == hideButton)
                {
                    frame1.setVisible(true);
                    frame2.setVisible(false);
                    frame2.dispose();
                }
            }
        };

        showButton.addActionListener(action);
        hideButton.addActionListener(action);

        contentPane1.add(showButton);

        frame1.getContentPane().add(contentPane1);
        frame1.setSize(300, 300);
        frame1.setVisible(true);
    }
    public static void main(String... args)
    {
        /*
         * Here we are Scheduling a JOB for Event Dispatcher
         * Thread. The code which is responsible for creating
         * and displaying our GUI or call to the method which 
         * is responsible for creating and displaying your GUI
         * goes into this SwingUtilities.invokeLater(...) thingy.
         */
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                new TwoFrames().createAndDisplayGUI();
            }
        });
    }
}

And the output will be :

Frame1 and Frame2

How can I get phone serial number (IMEI)

try this

 final TelephonyManager tm =(TelephonyManager)getBaseContext().getSystemService(Context.TELEPHONY_SERVICE);

  String deviceid = tm.getDeviceId();

Remove characters from a String in Java

This will safely remove only if token is at end of string.

StringUtils.removeEnd(string, ".xml");

Apache StringUtils functions are null-, empty-, and no match- safe

Why does GitHub recommend HTTPS over SSH?

I assume HTTPS is recommended by GitHub for several reasons

It's simpler to access a repository from anywhere as you only need your account details (no SSH keys required) to write to the repository.
HTTPS Is a port that is open in all firewalls. SSH is not always open as a port for communication to external networks

A GitHub repository is therefore more universally accessible using HTTPS than SSH.

In my view SSH keys are worth the little extra work in creating them

SSH Keys do not provide access to your GitHub account, so your account cannot be hijacked if your key is stolen.
Using a strong keyphrase with your SSH key limits any misuse, even if your key gets stolen (after first breaking access protection to your computer account)

If your GitHub account credentials (username/password) are stolen, your GitHub password can be changed to block you from access and all your shared repositories can be quickly deleted.

If a private key is stolen, someone can do a force push of an empty repository and wipe out all change history for each repository you own, but cannot change anything in your GitHub account. It will be much easier to try recovery from this breach of you have access to your GitHub account.

My preference is to use SSH with a passphrase protected key. I have a different SSH key for each computer, so if that machine gets stolen or key compromised, I can quickly login to GitHub and delete that key to prevent unwanted access.

SSH can be tunneled over HTTPS if the network you are on blocks the SSH port.

https://help.github.com/articles/using-ssh-over-the-https-port/

If you use HTTPS, I would recommend adding two-factor authentication, to protect your account as well as your repositories.

If you use HTTPS with a tool (e.g an editor), you should use a developer token from your GitHub account rather than cache username and password in that tools configuration. A token would mitigate the some of the potential risk of using HTTPS, as tokens can be configured for very specific access privileges and easily be revoked if that token is compromised.

Hibernate SessionFactory vs. JPA EntityManagerFactory

I prefer the JPA2 EntityManager API over SessionFactory, because it feels more modern. One simple example:

JPA:

@PersistenceContext
EntityManager entityManager;

public List<MyEntity> findSomeApples() {
  return entityManager
     .createQuery("from MyEntity where apples=7", MyEntity.class)
     .getResultList();
}

SessionFactory:

@Autowired
SessionFactory sessionFactory;

public List<MyEntity> findSomeApples() {
  Session session = sessionFactory.getCurrentSession();
  List<?> result = session.createQuery("from MyEntity where apples=7")
      .list();
  @SuppressWarnings("unchecked")
  List<MyEntity> resultCasted = (List<MyEntity>) result;
  return resultCasted;
}

I think it's clear that the first one looks cleaner and is also easier to test because EntityManager can be easily mocked.

javascript: calculate x% of a number

var number = 10000;
var result = .358 * number;

Django 1.7 - makemigrations not detecting changes

Maybe this will help someone.

I've deleted my models.py and expected makemigrations to create DeleteModel statements.

Remember to delete *.pyc files!

Overwriting my local branch with remote branch

git reset --hard

This is to revert all your local changes to the origin head

How can I center an image in Bootstrap?

Since the img is an inline element, Just use text-center on it's container. Using mx-auto will center the container (column) too.

<div class="row">
    <div class="col-4 mx-auto text-center">
        <img src="..">
    </div>
</div>

By default, images are display:inline. If you only want the center the image (and not the other column content), make the image display:block using the d-block class, and then mx-auto will work.

<div class="row">
  <div class="col-4">
    <img class="mx-auto d-block" src="..">
  </div>
</div>

Demo: http://codeply.com/go/iakGGLdB8s

Assign value from successful promise resolve to external variable

You could provide your function with the object and its attribute. Next, do what you need to do inside the function. Finally, assign the value returned in the promise to the right place in your object. Here's an example:

let myFunction = function (vm, feed) {
    getFeed().then( data => {
        vm[feed] = data
    })
} 

myFunction(vm, "feed")

You can also write a self-invoking function if you want.

Statistics: combinations in Python

Why not write it yourself? It's a one-liner or such:

from operator import mul    # or mul=lambda x,y:x*y
from fractions import Fraction

def nCk(n,k): 
  return int( reduce(mul, (Fraction(n-i, i+1) for i in range(k)), 1) )

Test - printing Pascal's triangle:

>>> for n in range(17):
...     print ' '.join('%5d'%nCk(n,k) for k in range(n+1)).center(100)
...     
                                                   1                                                
                                                1     1                                             
                                             1     2     1                                          
                                          1     3     3     1                                       
                                       1     4     6     4     1                                    
                                    1     5    10    10     5     1                                 
                                 1     6    15    20    15     6     1                              
                              1     7    21    35    35    21     7     1                           
                           1     8    28    56    70    56    28     8     1                        
                        1     9    36    84   126   126    84    36     9     1                     
                     1    10    45   120   210   252   210   120    45    10     1                  
                  1    11    55   165   330   462   462   330   165    55    11     1               
               1    12    66   220   495   792   924   792   495   220    66    12     1            
            1    13    78   286   715  1287  1716  1716  1287   715   286    78    13     1         
         1    14    91   364  1001  2002  3003  3432  3003  2002  1001   364    91    14     1      
      1    15   105   455  1365  3003  5005  6435  6435  5005  3003  1365   455   105    15     1   
    1    16   120   560  1820  4368  8008 11440 12870 11440  8008  4368  1820   560   120    16     1
>>>

PS. edited to replace int(round(reduce(mul, (float(n-i)/(i+1) for i in range(k)), 1))) with int(reduce(mul, (Fraction(n-i, i+1) for i in range(k)), 1)) so it won't err for big N/K

Regex to match alphanumeric and spaces

I suspect ^ doesn't work the way you think it does outside of a character class.

What you're telling it to do is replace everything that isn't an alphanumeric with an empty string, OR any leading space. I think what you mean to say is that spaces are ok to not replace - try moving the \s into the [] class.

Redirect on select option in select box

    {{-- dynamic select/dropdown --}}
    <select class="form-control m-bot15" name="district_id" 
        onchange ="location = this.options[this.selectedIndex].value;"
        >
          <option value="">--Select--</option>
          <option value="?">All</option>

            @foreach($location as $district)
                <option  value="?district_id={{ $district->district_id }}" >
                  {{ $district->district }}
                </option> 
            @endforeach   

    </select>

HTTPS and SSL3_GET_SERVER_CERTIFICATE:certificate verify failed, CA is OK

I have the same error on amazon AMI linux.

I Solved by setting curl.cainfo on /etc/php.d/curl.ini

https://gist.github.com/reinaldomendes/97fb2ce8a606ec813c4b

Addition October 2018

On Amazon Linux v1 edit this file

vi /etc/php.d/20-curl.ini

To add this line

curl.cainfo="/etc/ssl/certs/ca-bundle.crt"

Parallel.ForEach vs Task.Factory.StartNew

The first is a much better option.

Parallel.ForEach, internally, uses a Partitioner<T> to distribute your collection into work items. It will not do one task per item, but rather batch this to lower the overhead involved.

The second option will schedule a single Task per item in your collection. While the results will be (nearly) the same, this will introduce far more overhead than necessary, especially for large collections, and cause the overall runtimes to be slower.

FYI - The Partitioner used can be controlled by using the appropriate overloads to Parallel.ForEach, if so desired. For details, see Custom Partitioners on MSDN.

The main difference, at runtime, is the second will act asynchronous. This can be duplicated using Parallel.ForEach by doing:

Task.Factory.StartNew( () => Parallel.ForEach<Item>(items, item => DoSomething(item)));

By doing this, you still take advantage of the partitioners, but don't block until the operation is complete.

Read from file in eclipse

Did you try refreshing (right click -> refresh) the project folder after copying the file in there? That will SYNC your file system with Eclipse's internal file system.

When you run Eclipse projects, the CWD (current working directory) is project's root directory. Not bin's directory. Not src's directory, but the root dir.

Also, if you're in Linux, remember that its file systems are usually case sensitive.

Access nested dictionary items via a list of keys?

How about check and then set dict element without processing all indexes twice?

Solution:

def nested_yield(nested, keys_list):
    """
    Get current nested data by send(None) method. Allows change it to Value by calling send(Value) next time
    :param nested: list or dict of lists or dicts
    :param keys_list: list of indexes/keys
    """
    if not len(keys_list):  # assign to 1st level list
        if isinstance(nested, list):
            while True:
                nested[:] = yield nested
        else:
            raise IndexError('Only lists can take element without key')


    last_key = keys_list.pop()
    for key in keys_list:
        nested = nested[key]

    while True:
        try:
            nested[last_key] = yield nested[last_key]
        except IndexError as e:
            print('no index {} in {}'.format(last_key, nested))
            yield None

Example workflow:

ny = nested_yield(nested_dict, nested_address)
data_element = ny.send(None)
if data_element:
    # process element
    ...
else:
    # extend/update nested data
    ny.send(new_data_element)
    ...
ny.close()

Test

>>> cfg= {'Options': [[1,[0]],[2,[4,[8,16]]],[3,[9]]]}
    ny = nested_yield(cfg, ['Options',1,1,1])
    ny.send(None)
[8, 16]
>>> ny.send('Hello!')
'Hello!'
>>> cfg
{'Options': [[1, [0]], [2, [4, 'Hello!']], [3, [9]]]}
>>> ny.close()

how to get rid of notification circle in right side of the screen?

This stuff comes from ES file explorer

Just go into this app > settings

Then there is an option that says logging floating window, you just need to disable that and you will get rid of this infernal bubble for good

convert nan value to zero

You can use numpy.nan_to_num :

numpy.nan_to_num(x) : Replace nan with zero and inf with finite numbers.

Example (see doc) :

>>> np.set_printoptions(precision=8)
>>> x = np.array([np.inf, -np.inf, np.nan, -128, 128])
>>> np.nan_to_num(x)
array([  1.79769313e+308,  -1.79769313e+308,   0.00000000e+000,
        -1.28000000e+002,   1.28000000e+002])

create unique id with javascript

var id = "id" + Math.random().toString(16).slice(2)

Resize external website content to fit iFrame width

Tip for 1 website resizing the height. But you can change to 2 websites.

Here is my code to resize an iframe with an external website. You need insert a code into the parent (with iframe code) page and in the external website as well, so, this won't work with you don't have access to edit the external website.

local (iframe) page: just insert a code snippet
remote (external) page: you need a "body onload" and a "div" that holds all contents. And body needs to be styled to "margin:0"

Local:

<IFRAME STYLE="width:100%;height:1px" SRC="http://www.remote-site.com/" FRAMEBORDER="no" BORDER="0" SCROLLING="no" ID="estframe"></IFRAME>

<SCRIPT>
var eventMethod = window.addEventListener ? "addEventListener" : "attachEvent";
var eventer = window[eventMethod];
var messageEvent = eventMethod == "attachEvent" ? "onmessage" : "message";
eventer(messageEvent,function(e) {
  if (e.data.substring(0,3)=='frm') document.getElementById('estframe').style.height = e.data.substring(3) + 'px';
},false);
</SCRIPT>

You need this "frm" prefix to avoid problems with other embeded codes like Twitter or Facebook plugins. If you have a plain page, you can remove the "if" and the "frm" prefix on both pages (script and onload).

Remote:

You need jQuery to accomplish about "real" page height. I cannot realize how to do with pure JavaScript since you'll have problem when resize the height down (higher to lower height) using body.scrollHeight or related. For some reason, it will return always the biggest height (pre-redimensioned).

<BODY onload="parent.postMessage('frm'+$('#master').height(),'*')" STYLE="margin:0">
<SCRIPT SRC="path-to-jquery/jquery.min.js"></SCRIPT>
<DIV ID="master">
your content
</DIV>

So, parent page (iframe) has a 1px default height. The script inserts a "wait for message/event" from the iframe. When a message (post message) is received and the first 3 chars are "frm" (to avoid the mentioned problem), will get the number from 4th position and set the iframe height (style), including 'px' unit.

The external site (loaded in the iframe) will "send a message" to the parent (opener) with the "frm" and the height of the main div (in this case id "master"). The "*" in postmessage means "any source".

Hope this helps. Sorry for my english.

GROUP BY and COUNT in PostgreSQL

Using OVER() and LIMIT 1:

SELECT COUNT(1) OVER()
FROM posts 
   INNER JOIN votes ON votes.post_id = posts.id 
GROUP BY posts.id
LIMIT 1;

Using Selenium Web Driver to retrieve value of a HTML input

As was mentioned before, you could do something like that

public String getVal(WebElement webElement) {
    JavascriptExecutor e = (JavascriptExecutor) driver;
    return (String) e.executeScript(String.format("return $('#%s').val();", webElement.getAttribute("id")));
}

But as you can see, your element must have an id attribute, and also, jquery on your page.

How can I analyze a heap dump in IntelliJ? (memory leak)

There also exists a 'JVM Debugger Memory View' found in the plugin repository, which could be useful.

python numpy ValueError: operands could not be broadcast together with shapes

Convert the arrays to matrices, and then perform the multiplication.

X = np.matrix(X)

y = np.matrix(y)

X*y

How to set a value for a selectize.js input?

Note setValue only works if there are already predefined set of values for the selectize control ( ex. select field ), for controls where the value could be dynamic ( ex. user can add values on the fly, textbox field ) setValue ain't gonna work.

Use createItem functon instead for adding and setting the current value of the selectize field

ex.

$selectize[ 0 ].selectize.clear(); // Clear existing entries
for ( var i = 0 ; i < data_source.length ; i++ ) // data_source is a dynamic source of data
    $selectize[ 0 ].selectize.createItem( data_source[ i ] , false ); // false means don't trigger dropdown

What is the difference between origin and upstream on GitHub?

In a nutshell answer.

origin: the fork
upstream: the forked

Common CSS Media Queries Break Points

Rather than try to target @media rules at specific devices, it is arguably more practical to base them on your particular layout instead. That is, gradually narrow your desktop browser window and observe the natural breakpoints for your content. It's different for every site. As long as the design flows well at each browser width, it should work pretty reliably on any screen size (and there are lots and lots of them out there.)

How to call a asp:Button OnClick event using JavaScript?

If you're open to using jQuery:

<script type="text/javascript">
 function fncsave()
 {
    $('#<%= savebtn.ClientID %>').click();
 }
</script>

Also, if you are using .NET 4 or better you can make the ClientIDMode == static and simplify the code:

<script type="text/javascript">
 function fncsave()
 {
    $("#savebtn").click();
 }
</script>

Reference: MSDN Article for Control.ClientIDMode

Creating an array from a text file in Bash

mapfile and readarray (which are synonymous) are available in Bash version 4 and above. If you have an older version of Bash, you can use a loop to read the file into an array:

arr=()
while IFS= read -r line; do
  arr+=("$line")
done < file

In case the file has an incomplete (missing newline) last line, you could use this alternative:

arr=()
while IFS= read -r line || [[ "$line" ]]; do
  arr+=("$line")
done < file

Need alternative to readarray/mapfile for script on older version of Bash

Python 101: Can't open file: No such file or directory

I resolved this problem by navigating to C:\Python27\Scripts folder and then run file.py file instead of C:\Python27 folder

How to obtain the total numbers of rows from a CSV file in Python?

To do it you need to have a bit of code like my example here:

file = open("Task1.csv")
numline = len(file.readlines())
print (numline)

I hope this helps everyone.

How to use pagination on HTML tables?

With Reference to Anusree answer above and with respect,I am tweeking the code little bit to make sure it works in most of the cases.

Created a reusable function paginate('#myTableId') which can be called any number times for any table.
Adding code inside ajaxComplete function to make sure paging is called once table using jquery is completely loaded. We use paging mostly for ajax based tables.
Remove Pagination div and rebind on every pagination call
Configuring Number of rows per page

Code:

$(document).ready(function () {
    $(document).ajaxComplete(function () {
        paginate('#myTableId',10);
        function paginate(tableName,RecordsPerPage) {
            $('#nav').remove();
            $(tableName).after('<div id="nav"></div>');
            var rowsShown = RecordsPerPage;
            var rowsTotal = $(tableName + ' tbody tr').length;
            var numPages = rowsTotal / rowsShown;
            for (i = 0; i < numPages; i++) {
                var pageNum = i + 1;
                $('#nav').append('<a href="#" rel="' + i + '">' + pageNum + '</a> ');
            }
            $(tableName + ' tbody tr').hide();
            $(tableName + ' tbody tr').slice(0, rowsShown).show();
            $('#nav a:first').addClass('active');
            $('#nav a').bind('click', function () {

                $('#nav a').removeClass('active');
                $(this).addClass('active');
                var currPage = $(this).attr('rel');
                var startItem = currPage * rowsShown;
                var endItem = startItem + rowsShown;
                $(tableName + ' tbody tr').css('opacity', '0.0').hide().slice(startItem, endItem).
                    css('display', 'table-row').animate({ opacity: 1 }, 300);
            });
        }
    });
});

Absolute Positioning & Text Alignment

The div doesn't take up all the available horizontal space when absolutely positioned. Explicitly setting the width to 100% will solve the problem:

HTML

<div id="my-div">I want to be centered</div>?

CSS

#my-div {
   position: absolute;
   bottom: 15px;
   text-align: center;
   width: 100%;
}

how to convert from int to char*?

C-style solution could be to use itoa, but better way is to print this number into string by using sprintf / snprintf. Check this question: How to convert an integer to a string portably?

Note that itoa function is not defined in ANSI-C and is not part of C++, but is supported by some compilers. It's a non-standard function, thus you should avoid using it. Check this question too: Alternative to itoa() for converting integer to string C++?

Also note that writing C-style code while programming in C++ is considered bad practice and sometimes referred as "ghastly style". Do you really want to convert it into C-style char* string? :)

Pointers in Python?

There's no way you can do that changing only that line. You can do:

a = [1]
b = a
a[0] = 2
b[0]

That creates a list, assigns the reference to a, then b also, uses the a reference to set the first element to 2, then accesses using the b reference variable.

react native get TextInput value

Did you try

var username=this.state.username;

Regex for Comma delimited list

/^\d+(?:, ?\d+)*$/

Use a normal link to submit a form

You can't really do this without some form of scripting to the best of my knowledge.

<form id="my_form">
<!-- Your Form -->    
<a href="javascript:{}" onclick="document.getElementById('my_form').submit(); return false;">submit</a>
</form>

Example from Here.

How to use a class object in C++ as a function parameter

I was asking the same too. Another solution is you could overload your method:

void remove_id(EmployeeClass);
void remove_id(ProductClass);
void remove_id(DepartmentClass);

in the call the argument will fit accordingly the object you pass. but then you will have to repeat yourself

void remove_id(EmployeeClass _obj) {
    int saveId = _obj->id;
    ...
};

void remove_id(ProductClass _obj) {
    int saveId = _obj->id;
    ...
};

void remove_id(DepartmentClass _obj) {
    int saveId = _obj->id;
    ...
};

Parsing JSON from URL

public static TargetClassJson downloadPaletteJson(String url) throws IOException {
        if (StringUtils.isBlank(url)) {
            return null;
        }
        String genreJson = IOUtils.toString(new URL(url).openStream());
        return new Gson().fromJson(genreJson, TargetClassJson.class);
    }

How to access parameters in a Parameterized Build?

I think the variable is available directly, rather than through env, when using Workflow plugin. Try:

node()
{
    print "DEBUG: parameter foo = ${foo}"
}

Is there a way to get rid of accents and convert a whole string to regular letters?

EDIT: If you're not stuck with Java <6 and speed is not critical and/or translation table is too limiting, use answer by David. The point is to use Normalizer (introduced in Java 6) instead of translation table inside the loop.

While this is not "perfect" solution, it works well when you know the range (in our case Latin1,2), worked before Java 6 (not a real issue though) and is much faster than the most suggested version (may or may not be an issue):

    /**
 * Mirror of the unicode table from 00c0 to 017f without diacritics.
 */
private static final String tab00c0 = "AAAAAAACEEEEIIII" +
    "DNOOOOO\u00d7\u00d8UUUUYI\u00df" +
    "aaaaaaaceeeeiiii" +
    "\u00f0nooooo\u00f7\u00f8uuuuy\u00fey" +
    "AaAaAaCcCcCcCcDd" +
    "DdEeEeEeEeEeGgGg" +
    "GgGgHhHhIiIiIiIi" +
    "IiJjJjKkkLlLlLlL" +
    "lLlNnNnNnnNnOoOo" +
    "OoOoRrRrRrSsSsSs" +
    "SsTtTtTtUuUuUuUu" +
    "UuUuWwYyYZzZzZzF";

/**
 * Returns string without diacritics - 7 bit approximation.
 *
 * @param source string to convert
 * @return corresponding string without diacritics
 */
public static String removeDiacritic(String source) {
    char[] vysl = new char[source.length()];
    char one;
    for (int i = 0; i < source.length(); i++) {
        one = source.charAt(i);
        if (one >= '\u00c0' && one <= '\u017f') {
            one = tab00c0.charAt((int) one - '\u00c0');
        }
        vysl[i] = one;
    }
    return new String(vysl);
}

Tests on my HW with 32bit JDK show that this performs conversion from àèélštc89FDC to aeelstc89FDC 1 million times in ~100ms while Normalizer way makes it in 3.7s (37x slower). In case your needs are around performance and you know the input range, this may be for you.

Enjoy :-)

Run PHP function on html button click

Use ajax, a simple example,

HTML

<button id="button">Get Data</button>

Javascript

var button = document.getElementById("button");

button.addEventListener("click" ajaxFunction, false);

var ajaxFunction = function () {
    // ajax code here
}

Alternatively look into jquery ajax http://api.jquery.com/jQuery.ajax/

How to find a value in an excel column by vba code Cells.Find

Just use

Dim Cell As Range
Columns("B:B").Select
Set cell = Selection.Find(What:="celda", After:=ActiveCell, LookIn:=xlFormulas, _
        LookAt:=xlWhole, SearchOrder:=xlByRows, SearchDirection:=xlNext, _
        MatchCase:=False, SearchFormat:=False)

If cell Is Nothing Then
    'do it something

Else
    'do it another thing
End If

Removing header column from pandas dataframe

I had the same problem but solved it in this way:

df = pd.read_csv('your-array.csv', skiprows=[0])

How to get post slug from post in WordPress?

Here is most advanced and updated version what cover many cases:

if(!function_exists('the_slug')):
    function the_slug($post_id=false, $echo=true) {
        global $product, $page;

        if(is_numeric($post_id) && $post_id == intval($post_id)) {} else {
            if(!is_object($post_id)){}else if(property_exists($post_id, 'ID')){
                $post_id = $post_id->ID;
            }
            if(empty($post_id) && property_exists($product, 'ID')) $post_id = $product->ID;
            if(empty($post_id)) $post_id =  get_the_ID();

            if(empty($post_id) && property_exists($page, 'ID')) $post_id =  $page->ID;
        }

        if(!empty($post_id))
            $slug = basename(get_permalink($post_id));
        else
            $slug = basename(get_permalink());
        do_action('before_slug', $slug);
        $slug = apply_filters('slug_filter', $slug);
        if( $echo ) echo $slug;
        do_action('after_slug', $slug);
        return $slug;
      }
endif;

This is collections from the best answers and few my updates.

Conversion from 12 hours time to 24 hours time in java

I was looking for same thing but in number, means from integer xx hour, xx minutes and AM/PM to 24 hour format xx hour and xx minutes, so here what i have done:

private static final int AM = 0;
private static final int PM = 1;
/**
   * Based on concept: day start from 00:00AM and ends at 11:59PM, 
   * afternoon 12 is 12PM, 12:xxAM is basically 00:xxAM
   * @param hour12Format
   * @param amPm
   * @return
   */
  private int get24FormatHour(int hour12Format,int amPm){
    if(hour12Format==12 && amPm==AM){
      hour12Format=0;
    }
    if(amPm == PM && hour12Format!=12){
      hour12Format+=12;
    }
    return hour12Format;
  }`

    private int minutesTillMidnight(int hour12Format,int minutes, int amPm){
        int hour24Format=get24FormatHour(hour12Format,amPm);
        System.out.println("24 Format :"+hour24Format+":"+minutes); 
        return (hour24Format*60)+minutes;
      }

How to use environment variables in docker compose

Use .env file to define dynamic values in docker-compse.yml. Be it port or any other value.

Sample docker-compose:

testcore.web:
       image: xxxxxxxxxxxxxxx.dkr.ecr.ap-northeast-2.amazonaws.com/testcore:latest
       volumes: 
            - c:/logs:c:/logs
       ports:
            - ${TEST_CORE_PORT}:80
       environment:
            - CONSUL_URL=http://${CONSUL_IP}:8500 
            - HOST=${HOST_ADDRESS}:${TEST_CORE_PORT}

Inside .env file you can define the value of these variables:

CONSUL_IP=172.31.28.151
HOST_ADDRESS=172.31.16.221
TEST_CORE_PORT=10002

catch specific HTTP error in python

Python 3

from urllib.error import HTTPError

Python 2

from urllib2 import HTTPError

Just catch HTTPError, handle it, and if it's not Error 404, simply use raise to re-raise the exception.

See the Python tutorial.

e.g. complete example for Pyhton 2

import urllib2
from urllib2 import HTTPError
try:
   urllib2.urlopen("some url")
except HTTPError as err:
   if err.code == 404:
       <whatever>
   else:
       raise

How can I remove a character from a string using JavaScript?

Create function like below

  String.prototype.replaceAt = function (index, char) {
      if(char=='') {
          return this.slice(0,index)+this.substr(index+1 + char.length);
      } else {
          return this.substr(0, index) + char + this.substr(index + char.length);
      }
  }

To replace give character like below

  var a="12346";
  a.replaceAt(4,'5');

and to remove character at definite index, give second parameter as empty string

a.replaceAt(4,'');

How do you run a Python script as a service in Windows?

nssm in python 3+

(I converted my .py file to .exe with pyinstaller)

nssm: as said before

run nssm install {ServiceName}
On NSSM´s console:

path: path\to\your\program.exe

Startup directory: path\to\your\ #same as the path but without your program.exe

Arguments: empty

If you don't want to convert your project to .exe

create a .bat file with python {{your python.py file name}}
and set the path to the .bat file

How to remove leading and trailing white spaces from a given html string?

var trim = your_string.replace(/^\s+|\s+$/g, '');

Eclipse keyboard shortcut to indent source code to the left?

control + shift + F will do the work

Document Root PHP

<a href="<?php echo $_SERVER['DOCUMENT_ROOT'].'/hello.html'; ?>">go with php</a>
    <br />
<a href="/hello.html">go to with html</a>

Try this yourself and find that they are not exactly the same.

$_SERVER['DOCUMENT_ROOT'] renders an actual file path (on my computer running as it's own server, C:/wamp/www/

HTML's / renders the root of the server url, in my case, localhost/

But C:/wamp/www/hello.html and localhost/hello.html are in fact the same file

Programmatically go back to the previous fragment in the backstack

To elaborate on the other answers provided, this is my solution (placed in an Activity):

@Override
public void onBackPressed(){
    FragmentManager fm = getFragmentManager();
    if (fm.getBackStackEntryCount() > 0) {
        Log.i("MainActivity", "popping backstack");
        fm.popBackStack();
    } else {
        Log.i("MainActivity", "nothing on backstack, calling super");
        super.onBackPressed();  
    }
}

How do I query using fields inside the new PostgreSQL JSON datatype?

With Postgres 9.3+, just use the -> operator. For example,

SELECT data->'images'->'thumbnail'->'url' AS thumb FROM instagram;

see http://clarkdave.net/2013/06/what-can-you-do-with-postgresql-and-json/ for some nice examples and a tutorial.

How to print a number with commas as thousands separators in JavaScript

If you're looking for a short and sweet solution:

const number = 12345678.99;

const numberString = String(number).replace(
    /^\d+/,
    number => [...number].map(
        (digit, index, digits) => (
            !index || (digits.length - index) % 3 ? '' : ','
        ) + digit
    ).join('')
);

// numberString: 12,345,678.99

How to select option in drop down using Capybara

Here's the most concise way I've found (using capybara 3.3.0 and chromium driver):

all('#id-of-select option')[1].select_option

will select the 2nd option. Increment the index as needed.

Is Django for the frontend or backend?

Neither.

Django is a framework, not a language. Python is the language in which Django is written.

Django is a collection of Python libs allowing you to quickly and efficiently create a quality Web application, and is suitable for both frontend and backend.

However, Django is pretty famous for its "Django admin", an auto generated backend that allows you to manage your website in a blink for a lot of simple use cases without having to code much.

More precisely, for the front end, Django helps you with data selection, formatting, and display. It features URL management, a templating language, authentication mechanisms, cache hooks, and various navigation tools such as paginators.

For the backend, Django comes with an ORM that lets you manipulate your data source with ease, forms (an HTML independent implementation) to process user input and validate data and signals, and an implementation of the observer pattern. Plus a tons of use-case specific nifty little tools.

For the rest of the backend work Django doesn't help with, you just use regular Python. Business logic is a pretty broad term.

You probably want to know as well that Django comes with the concept of apps, a self contained pluggable Django library that solves a problem. The Django community is huge, and so there are numerous apps that do specific business logic that vanilla Django doesn't.

Binding IIS Express to an IP Address

As mentioned above, edit the application host.config. An easy way to find this is run your site in VS using IIS Express. Right click the systray icon, show all applications. Choose your site, and then click on the config link at the bottom to open it.

I'd suggest adding another binding entry, and leave the initial localhost one there. This additional binding will appear in the IIS Express systray as a separate application under the site.

To avoid having to run VS as admin (lots of good reasons not to run as admin), add a netsh rule as follows (obviously replacing the IP and port with your values) - you'll need an admin cmd.exe for this, it only needs to be run once:

netsh http add urlacl url=http://192.168.1.121:51652/ user=\Everyone

netsh can add rules like url=http://+:51652/ but I failed to get this to place nicely with IIS Express. You can use netsh http show urlacl to list existing rules, and they can be deleted with netsh http delete urlacl url=blah.

Further info: http://msdn.microsoft.com/en-us/library/ms733768.aspx

Accessing all items in the JToken

You can cast your JToken to a JObject and then use the Properties() method to get a list of the object properties. From there, you can get the names rather easily.

Something like this:

string json =
@"{
    ""ADDRESS_MAP"":{

        ""ADDRESS_LOCATION"":{
            ""type"":""separator"",
            ""name"":""Address"",
            ""value"":"""",
            ""FieldID"":40
        },
        ""LOCATION"":{
            ""type"":""locations"",
            ""name"":""Location"",
            ""keyword"":{
                ""1"":""LOCATION1""
            },
            ""value"":{
                ""1"":""United States""
            },
            ""FieldID"":41
        },
        ""FLOOR_NUMBER"":{
            ""type"":""number"",
            ""name"":""Floor Number"",
            ""value"":""0"",
            ""FieldID"":55
        },
        ""self"":{
            ""id"":""2"",
            ""name"":""Address Map""
        }
    }
}";

JToken outer = JToken.Parse(json);
JObject inner = outer["ADDRESS_MAP"].Value<JObject>();

List<string> keys = inner.Properties().Select(p => p.Name).ToList();

foreach (string k in keys)
{
    Console.WriteLine(k);
}

Output:

ADDRESS_LOCATION
LOCATION
FLOOR_NUMBER
self

Programs & Examples On #Arcgis

"Uncaught SyntaxError: Cannot use import statement outside a module" when importing ECMAScript 6

java.security.cert.CertificateException: Certificates does not conform to algorithm constraints

How do I check out an SVN project into Eclipse as a Java project?

How can you profile a Python script?

pprofile

vprof

How do I release memory used by a pandas dataframe?

Reducing the Number of Dataframes

Reducing Dataframe Size

Viewing Memory Usage

forcing web-site to show in landscape mode only

@Golmaal really answered this, I'm just being a bit more verbose.

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Disable the postback on an <ASP:LinkButton>

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No provider for TemplateRef! (NgIf ->TemplateRef)

T-SQL CASE Clause: How to specify WHEN NULL

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PHP function to generate v4 UUID

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Refresh certain row of UITableView based on Int in Swift

ORA-00932: inconsistent datatypes: expected - got CLOB

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SPAN vs DIV (inline-block)

What causes a TCP/IP reset (RST) flag to be sent?

Border Height on CSS

adding to window.onload event?

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How to hide html source & disable right click and text copy?

How to properly seed random number generator

Pandas: Return Hour from Datetime Column Directly

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Laravel Eloquent update just if changes have been made

If else in stored procedure sql server

What strategies and tools are useful for finding memory leaks in .NET?

Automate scp file transfer using a shell script

Search for executable files using find command

Where can I find the TypeScript version installed in Visual Studio?

Capitalize the first letter of both words in a two word string

Where does Hive store files in HDFS?

Python: count repeated elements in the list

What's the UIScrollView contentInset property for?

How to convert seconds to time format?

Replacing accented characters php

Git:nothing added to commit but untracked files present

how to increment integer Columns value by 1 in SQL

Sharing a variable between multiple different threads

How do I make a dictionary with multiple keys to one value?

Which mime type should I use for mp3