Programs & Examples On #Spreadsheetgear

SpreadsheetGear 2012 enables ASP.NET, Windows Forms, WPF and Silverlight developers to easily take advantage of scalable Excel Reporting, dynamic dashboards from Excel charts and ranges, powerful spreadsheet controls, comprehensive Excel compatible charting, the fastest and most complete Excel compatible calculations and more.

PHP - find entry by object property from an array of objects

$arr = [
  [
    'ID' => 1
  ]
];

echo array_search(1, array_column($arr, 'ID')); // prints 0 (!== false)

Above code echoes the index of the matching element, or false if none.

To get the corresponding element, do something like:

$i = array_search(1, array_column($arr, 'ID'));
$element = ($i !== false ? $arr[$i] : null);

array_column works both on an array of arrays, and on an array of objects.

react-native: command not found

In cmd Administration mode,Run

npm install react-native-cli

Clear the cache in JavaScript

I tend to version my framework then apply the version number to script and style paths

<cfset fw.version = '001' />
<script src="/scripts/#fw.version#/foo.js"/>

How to delete mysql database through shell command

In general, you can pass any query to mysql from shell with -e option.

mysql -u username -p -D dbname -e "DROP DATABASE dbname"

Nested routes with react router v4 / v5

A complete answer for React Router v5.


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

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

export default Dashboard;

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

Programmatically Add CenterX/CenterY Constraints

If you don't care about this question being specifically about a tableview, and you'd just like to center one view on top of another view here's to do it:

    let horizontalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: parentView, attribute: NSLayoutAttribute.CenterX, multiplier: 1, constant: 0)
    parentView.addConstraint(horizontalConstraint)

    let verticalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutAttribute.CenterY, relatedBy: NSLayoutRelation.Equal, toItem: parentView, attribute: NSLayoutAttribute.CenterY, multiplier: 1, constant: 0)
    parentView.addConstraint(verticalConstraint)

Truncating a table in a stored procedure

All DDL statements in Oracle PL/SQL should use Execute Immediate before the statement. Hence you should use:

execute immediate 'truncate table schema.tablename';

Checking if a variable is not nil and not zero in ruby

You could initialize discount to 0 as long as your code is guaranteed not to try and use it before it is initialized. That would remove one check I suppose, I can't think of anything else.

Removing display of row names from data frame

Recently I had the same problem when using htmlTable() (‘htmlTable’ package) and I found a simpler solution: convert the data frame to a matrix with as.matrix():

htmlTable(as.matrix(df))

And be sure that the rownames are just indices. as.matrix() conservs the same columnames. That's it.

UPDATE

Following the comment of @DMR, I did't notice that htmlTable() has the parameter rnames = FALSE for cases like this. So a better answer would be:

htmlTable(df, rnames = FALSE)

How can I check out a GitHub pull request with git?

Create a local branch

git checkout -b local-branch-name

Pull the remote PR

git pull [email protected]:your-repo-ssh.git remote-branch-name

Equivalent of jQuery .hide() to set visibility: hidden

An even simpler way to do this is to use jQuery's toggleClass() method

CSS

.newClass{visibility: hidden}

HTML

<a href="#" class=trigger>Trigger Element </a>
<div class="hidden_element">Some Content</div>

JS

$(document).ready(function(){
    $(".trigger").click(function(){
        $(".hidden_element").toggleClass("newClass");
    });
});

JVM heap parameters

The JVM resizes the heap adaptively, meaning it will attempt to find the best heap size for your application. -Xms and -Xmx simply specifies the range in which the JVM can operate and resize the heap. If -Xms and -Xmx are the same value, then the JVM's heap size will stay constant at that value.

It's typically best to just set -Xmx and let the JVM find the best heap size, unless there's a specific reason why you need to give the JVM a big heap at JVM launch.

As far as when the JVM actually requests the memory from the OS, I believe it depends on the platform and implementation of the JVM. I imagine that it wouldn't request the memory until your app actually needs it. -Xmx and -Xms just reserves the memory.

Eloquent get only one column as an array

You can use the pluck method:

Word_relation::where('word_one', $word_id)->pluck('word_two')->toArray();

For more info on what methods are available for using with collection, you can you can check out the Laravel Documentation.

Python Unicode Encode Error

I wrote the following to fix the nuisance non-ascii quotes and force conversion to something usable.

unicodeToAsciiMap = {u'\u2019':"'", u'\u2018':"`", }

def unicodeToAscii(inStr):
    try:
        return str(inStr)
    except:
        pass
    outStr = ""
    for i in inStr:
        try:
            outStr = outStr + str(i)
        except:
            if unicodeToAsciiMap.has_key(i):
                outStr = outStr + unicodeToAsciiMap[i]
            else:
                try:
                    print "unicodeToAscii: add to map:", i, repr(i), "(encoded as _)"
                except:
                    print "unicodeToAscii: unknown code (encoded as _)", repr(i)
                outStr = outStr + "_"
    return outStr

Best way to implement keyboard shortcuts in a Windows Forms application?

You probably forgot to set the form's KeyPreview property to True. Overriding the ProcessCmdKey() method is the generic solution:

protected override bool ProcessCmdKey(ref Message msg, Keys keyData) {
  if (keyData == (Keys.Control | Keys.F)) {
    MessageBox.Show("What the Ctrl+F?");
    return true;
  }
  return base.ProcessCmdKey(ref msg, keyData);
}

How to read a text file in project's root directory?

In this code you access to root directory project:

 string _filePath = Path.GetDirectoryName(System.AppDomain.CurrentDomain.BaseDirectory);

then:

StreamReader r = new StreamReader(_filePath + "/cities2.json"))

How do I restart a service on a remote machine in Windows?

You can use mmc:

  1. Start / Run. Type "mmc".
  2. File / Add/Remove Snap-in... Click "Add..."
  3. Find "Services" and click "Add"
  4. Select "Another computer:" and type the host name / IP address of the remote machine. Click Finish, Close, etc.

At that point you will be able to manage services as if they were on your local machine.

There is no tracking information for the current branch

See: git checkout tag, git pull fails in branch

If like me you need to do this all the time, you can set up an alias to do it automatically by adding the following to your .gitconfig file:

[alias]
    set-upstream = \
       !git branch \
           --set-upstream-to=origin/`git symbolic-ref --short HEAD`

When you see the message There is no tracking information..., run:

 git set-upstream
 git push

Thanks to https://zarino.co.uk/post/git-set-upstream/

Turn off display errors using file "php.ini"

You should consider not displaying your error messages instead!

Set ini_set('display_errors', 'Off'); in your PHP code (or directly into your ini file if possible), and leave error_reporting on E_ALL or whatever kind of messages you would like to find in your logs.

This way you can handle errors later, while your users still don't see them.

Full example:

define('DEBUG', true);
error_reporting(E_ALL);

if (DEBUG)
{
    ini_set('display_errors', 'On');
}
else
{
    ini_set('display_errors', 'Off');
}

Or simply (same effect):

define('DEBUG', true);

error_reporting(E_ALL);
ini_set('display_errors', DEBUG ? 'On' : 'Off');

What is the difference between conversion specifiers %i and %d in formatted IO functions (*printf / *scanf)

These are identical for printf but different for scanf. For printf, both %d and %i designate a signed decimal integer. For scanf, %d and %i also means a signed integer but %i inteprets the input as a hexadecimal number if preceded by 0x and octal if preceded by 0 and otherwise interprets the input as decimal.

Bootstrap 3 - How to load content in modal body via AJAX?

create an empty modal box on the current page and below is the ajax call you can see how to fetch the content in result from another html page.

 $.ajax({url: "registration.html", success: function(result){
            //alert("success"+result);
              $("#contentBody").html(result);
            $("#myModal").modal('show'); 

        }});

once the call is done you will get the content of the page by the result to then you can insert the code in you modal's content id using.

You can call controller and get the page content and you can show that in your modal.

below is the example of Bootstrap 3 modal in that we are loading content from registration.html page...

index.html
------------------------------------------------
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>

<script type="text/javascript">
function loadme(){
    //alert("loadig");

    $.ajax({url: "registration.html", success: function(result){
        //alert("success"+result);
          $("#contentBody").html(result);
        $("#myModal").modal('show'); 

    }});
}
</script>
</head>
<body>

<!-- Trigger the modal with a button -->
<button type="button" class="btn btn-info btn-lg" onclick="loadme()">Load me</button>


<!-- Modal -->
<div id="myModal" class="modal fade" role="dialog">
  <div class="modal-dialog">

    <!-- Modal content-->
    <div class="modal-content" >
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal">&times;</button>
        <h4 class="modal-title">Modal Header</h4>
      </div>
      <div class="modal-body" id="contentBody">

      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
      </div>
    </div>

  </div>
</div>

</body>
</html>

registration.html
-------------------- 
<!DOCTYPE html>
<html>
<style>
body {font-family: Arial, Helvetica, sans-serif;}

form {
    border: 3px solid #f1f1f1;
    font-family: Arial;
}

.container {
    padding: 20px;
    background-color: #f1f1f1;
    width: 560px;
}

input[type=text], input[type=submit] {
    width: 100%;
    padding: 12px;
    margin: 8px 0;
    display: inline-block;
    border: 1px solid #ccc;
    box-sizing: border-box;
}

input[type=checkbox] {
    margin-top: 16px;
}

input[type=submit] {
    background-color: #4CAF50;
    color: white;
    border: none;
}

input[type=submit]:hover {
    opacity: 0.8;
}
</style>
<body>

<h2>CSS Newsletter</h2>

<form action="/action_page.php">
  <div class="container">
    <h2>Subscribe to our Newsletter</h2>
    <p>Lorem ipsum text about why you should subscribe to our newsletter blabla. Lorem ipsum text about why you should subscribe to our newsletter blabla.</p>
  </div>

  <div class="container" style="background-color:white">
    <input type="text" placeholder="Name" name="name" required>
    <input type="text" placeholder="Email address" name="mail" required>
    <label>
      <input type="checkbox" checked="checked" name="subscribe"> Daily Newsletter
    </label>
  </div>

  <div class="container">
    <input type="submit" value="Subscribe">
  </div>
</form>

</body>
</html>

How is returning the output of a function different from printing it?

The below examples might help understand:

def add_nums1(x,y):
    print(x+y)

def add_nums2(x,y):
    return x+y 

#----Function output is usable for further processing
add_nums2(10,20)/2
15.0

#----Function output can't be used further (gives TypeError)
add_nums1(10,20)/2

30
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-124-e11302d7195e> in <module>
----> 1 add_nums1(10,20)/2

TypeError: unsupported operand type(s) for /: 'NoneType' and 'int'

getting the screen density programmatically in android?

Blundell's answer as a static helper method:

private static String getDensityName(Context context) {
    float density = context.getResources().getDisplayMetrics().density;
    if (density >= 4.0) {
        return "xxxhdpi";
    }
    if (density >= 3.0) {
        return "xxhdpi";
    }
    if (density >= 2.0) {
        return "xhdpi";
    }
    if (density >= 1.5) {
        return "hdpi";
    }
    if (density >= 1.0) {
        return "mdpi";
    }
    return "ldpi";
}

Responding with a JSON object in Node.js (converting object/array to JSON string)

const http = require('http');
const url = require('url');

http.createServer((req,res)=>{

    const parseObj =  url.parse(req.url,true);
    const users = [{id:1,name:'soura'},{id:2,name:'soumya'}]

    if(parseObj.pathname == '/user-details' && req.method == "GET") {
        let Id = parseObj.query.id;
        let user_details = {};
        users.forEach((data,index)=>{
            if(data.id == Id){
                user_details = data;
            }
        })
        res.writeHead(200,{'x-auth-token':'Auth Token'})
        res.write(JSON.stringify(user_details)) // Json to String Convert
        res.end();
    }
}).listen(8000);

I have used the above code in my existing project.

Make child div stretch across width of page

Yes you can, set the position: relative for the container and position: absolute for the help_panel

How to get the number of characters in a std::string?

If you're using old, C-style string instead of the newer, STL-style strings, there's the strlen function in the C run time library:

const char* p = "Hello";
size_t n = strlen(p);

How to add some non-standard font to a website?

If you use ASP.NET, it's really easy to generate image based fonts without actually having to install (as in adding to the installed font base) fonts on the server by using:

PrivateFontCollection pfont = new PrivateFontCollection();
pfont.AddFontFile(filename);
FontFamily ff = pfont.Families[0];

and then drawing with that font onto a Graphics.

Concatenating variables and strings in React

you can simply do this..

 <img src={"http://img.example.com/test/" + this.props.url +"/1.jpg"}/>

Swift presentViewController

You don't need to instantiate the ViewController in Storyboard just to get present() ViewController to work. That's a hackish solution.

If you see a black/blank screen when presenting a VC, it might be because you're calling present() from viewDidLoad() in the First/RootViewController, but the first View isn't ready yet.

Call present() from viewDidAppear to fix this, i.e.:

override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    let yourVC = YourViewController()
    self.present(yourVC, animated: true, completion: nil)
}

Once any "View" has appeared in your App, you can start calling present() from viewDidLoad().


Using UINavigationController (as suggested in an answer) is another option, but it might be an overkill to solve this issue. You might end up complicating the user flow. Use the UINavigationController based solution only if you want to have a NavigatonBar or want to return to the previous view controller.

What is the difference between atomic / volatile / synchronized?

I know that two threads can not enter in Synchronize block at the same time

Two thread cannot enter a synchronized block on the same object twice. This means that two threads can enter the same block on different objects. This confusion can lead to code like this.

private Integer i = 0;

synchronized(i) {
   i++;
}

This will not behave as expected as it could be locking on a different object each time.

if this is true than How this atomic.incrementAndGet() works without Synchronize ?? and is thread safe ??

yes. It doesn't use locking to achieve thread safety.

If you want to know how they work in more detail, you can read the code for them.

And what is difference between internal reading and writing to Volatile Variable / Atomic Variable ??

Atomic class uses volatile fields. There is no difference in the field. The difference is the operations performed. The Atomic classes use CompareAndSwap or CAS operations.

i read in some article that thread has local copy of variables what is that ??

I can only assume that it referring to the fact that each CPU has its own cached view of memory which can be different from every other CPU. To ensure that your CPU has a consistent view of data, you need to use thread safety techniques.

This is only an issue when memory is shared at least one thread updates it.

Install gitk on Mac

For Mojave users, I found this page very useful, particularly this suggestion:

/usr/bin/wish $(which gitk)

...without that, the window did not display correctly!

How to fill a datatable with List<T>

Just in case you have a nullable property in your class object:

private static DataTable ConvertToDatatable<T>(List<T> data)
{
    PropertyDescriptorCollection props = TypeDescriptor.GetProperties(typeof(T));
    DataTable table = new DataTable();
    for (int i = 0; i < props.Count; i++)
    {
        PropertyDescriptor prop = props[i];
        if (prop.PropertyType.IsGenericType && prop.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>))
            table.Columns.Add(prop.Name, prop.PropertyType.GetGenericArguments()[0]); 
        else
            table.Columns.Add(prop.Name, prop.PropertyType);
    }

    object[] values = new object[props.Count];
    foreach (T item in data)
    {
        for (int i = 0; i < values.Length; i++)
        {
            values[i] = props[i].GetValue(item);
        }
        table.Rows.Add(values);
    }
    return table;
 }

Java program to find the largest & smallest number in n numbers without using arrays

Try this...This simple

import java.util.Scanner;

class numbers
{
   public static void main(String args[])
   {
      int x, y, z;
      System.out.println("Enter three integers ");
      Scanner in = new Scanner(System.in);

      x = in.nextInt();
      y = in.nextInt();
      z = in.nextInt();

      if ( x > y && x > z )
         System.out.println("First number is largest.");
      else if ( y > x && y > z )
         System.out.println("Second number is largest.");
      else if ( z > x && z > y )
         System.out.println("Third number is largest.");
      else   
         System.out.println("Entered numbers are not distinct");
   }
}

Undefined Reference to

Another way to get this error is by accidentally writing the definition of something in an anonymous namespace:

foo.h:

namespace foo {
    void bar();
}

foo.cc:

namespace foo {
    namespace {  // wrong
        void bar() { cout << "hello"; };
    }
}

other.cc file:

#include "foo.h"

void baz() {
    foo::bar();
}

Showing Difference between two datetime values in hours

Is there a reason you're using Nullable?

If you want to use Nullable then you can write variable.Value.TotalHours.

Or you can just write: (datevalue1 - datevalue2).TotalHours.

git clone from another directory

cd /d c:\
git clone C:\folder1 folder2

From the documentation for git clone:

For local repositories, also supported by git natively, the following syntaxes may be used:

/path/to/repo.git/

file:///path/to/repo.git/

These two syntaxes are mostly equivalent, except the former implies --local option.

Why does the 260 character path length limit exist in Windows?

One way to cope with the path limit is to shorten path entries with symbolic links.

For example:

  1. create a C:\p directory to keep short links to long paths
  2. mklink /J C:\p\foo C:\Some\Crazy\Long\Path\foo
  3. add C:\p\foo to your path instead of the long path

How do you debug MySQL stored procedures?

I just simply place select statements in key areas of the stored procedure to check on current status of data sets, and then comment them out (--select...) or remove them before production.

Escape @ character in razor view engine

I know this question is old, but I tried all of the above and it didn't help me escape the character "@" in ASP.NET full framework (MVC 5) inside a URL. Based on Terje Solem's answer though, the UTF-8 code %40 worked for me. this is the original URL I was trying to reach:

https://unpkg.com/@google/[email protected]/dist/markerclustererplus.min.js

and with with the code in it:

https://unpkg.com/%40google/[email protected]/dist/markerclustererplus.min.js

How do I fix a "Expected Primary-expression before ')' token" error?

showInventory(player); is passing a type as parameter. That's illegal, you need to pass an object.

For example, something like:

player p;
showInventory(p);  

I'm guessing you have something like this:

int main()
{
   player player;
   toDo();
}

which is awful. First, don't name the object the same as your type. Second, in order for the object to be visible inside the function, you'll need to pass it as parameter:

int main()
{
   player p;
   toDo(p);
}

and

std::string toDo(player& p) 
{
    //....
    showInventory(p);
    //....
}

load scripts asynchronously

One reason why your scripts could be loading so slowly is if you were running all of your scripts while loading the page, like this:

callMyFunctions();

instead of:

$(window).load(function() {
      callMyFunctions();
});

This second bit of script waits until the browser has completely loaded all of your Javascript code before it starts executing any of your scripts, making it appear to the user that the page has loaded faster.

If you're looking to enhance the user's experience by decreasing the loading time, I wouldn't go for the "loading screen" option. In my opinion that would be much more annoying than just having the page load more slowly.

How to disable spring security for particular url

<http pattern="/resources/**" security="none"/>

Or with Java configuration:

web.ignoring().antMatchers("/resources/**");

Instead of the old:

 <intercept-url pattern="/resources/**" filters="none"/>

for exp . disable security for a login page :

  <intercept-url pattern="/login*" filters="none" />

Permissions error when connecting to EC2 via SSH on Mac OSx

None of the above helped me, but futzing with the user seemed like it had promise. For my config using 'ubuntu' was right.....

ssh -i [full path to keypair file] ubuntu@[EC2 instance hostname or IP address]

Installing a specific version of angular with angular cli

You can just have package.json with specific version and do npm install and it will install that version. Also you dont need to depend on angular-cli to develop your project.

Difference between HttpModule and HttpClientModule

There is a library which allows you to use HttpClient with strongly-typed callbacks.

The data and the error are available directly via these callbacks.

A reason for existing

When you use HttpClient with Observable, you have to use .subscribe(x=>...) in the rest of your code.

This is because Observable<HttpResponse<T>> is tied to HttpResponse.

This tightly couples the http layer with the rest of your code.

This library encapsulates the .subscribe(x => ...) part and exposes only the data and error through your Models.

With strongly-typed callbacks, you only have to deal with your Models in the rest of your code.

The library is called angular-extended-http-client.

angular-extended-http-client library on GitHub

angular-extended-http-client library on NPM

Very easy to use.

Sample usage

The strongly-typed callbacks are

Success:

  • IObservable<T>
  • IObservableHttpResponse
  • IObservableHttpCustomResponse<T>

Failure:

  • IObservableError<TError>
  • IObservableHttpError
  • IObservableHttpCustomError<TError>

Add package to your project and in your app module

import { HttpClientExtModule } from 'angular-extended-http-client';

and in the @NgModule imports

  imports: [
    .
    .
    .
    HttpClientExtModule
  ],

Your Models

//Normal response returned by the API.
export class RacingResponse {
    result: RacingItem[];
}

//Custom exception thrown by the API.
export class APIException {
    className: string;
}

Your Service

In your Service, you just create params with these callback types.

Then, pass them on to the HttpClientExt's get method.

import { Injectable, Inject } from '@angular/core'
import { RacingResponse, APIException } from '../models/models'
import { HttpClientExt, IObservable, IObservableError, ResponseType, ErrorType } from 'angular-extended-http-client';
.
.

@Injectable()
export class RacingService {

    //Inject HttpClientExt component.
    constructor(private client: HttpClientExt, @Inject(APP_CONFIG) private config: AppConfig) {

    }

    //Declare params of type IObservable<T> and IObservableError<TError>.
    //These are the success and failure callbacks.
    //The success callback will return the response objects returned by the underlying HttpClient call.
    //The failure callback will return the error objects returned by the underlying HttpClient call.
    getRaceInfo(success: IObservable<RacingResponse>, failure?: IObservableError<APIException>) {
        let url = this.config.apiEndpoint;

        this.client.get(url, ResponseType.IObservable, success, ErrorType.IObservableError, failure);
    }
}

Your Component

In your Component, your Service is injected and the getRaceInfo API called as shown below.

  ngOnInit() {    
    this.service.getRaceInfo(response => this.result = response.result,
                                error => this.errorMsg = error.className);

  }

Both, response and error returned in the callbacks are strongly typed. Eg. response is type RacingResponse and error is APIException.

You only deal with your Models in these strongly-typed callbacks.

Hence, The rest of your code only knows about your Models.

Also, you can still use the traditional route and return Observable<HttpResponse<T>> from Service API.

How to replace part of string by position?

ReplaceAt(int index, int length, string replace)

Here's an extension method that doesn't use StringBuilder or Substring. This method also allows the replacement string to extend past the length of the source string.

//// str - the source string
//// index- the start location to replace at (0-based)
//// length - the number of characters to be removed before inserting
//// replace - the string that is replacing characters
public static string ReplaceAt(this string str, int index, int length, string replace)
{
    return str.Remove(index, Math.Min(length, str.Length - index))
            .Insert(index, replace);
}

When using this function, if you want the entire replacement string to replace as many characters as possible, then set length to the length of the replacement string:

"0123456789".ReplaceAt(7, 5, "Hello") = "0123456Hello"

Otherwise, you can specify the amount of characters that will be removed:

"0123456789".ReplaceAt(2, 2, "Hello") = "01Hello456789"

If you specify the length to be 0, then this function acts just like the insert function:

"0123456789".ReplaceAt(4, 0, "Hello") = "0123Hello456789"

I guess this is more efficient since the StringBuilder class need not be initialized and since it uses more basic operations. Please correct me if I am wrong. :)

correct way of comparing string jquery operator =

First of all you should use double "==" instead of "=" to compare two values. Using "=" You assigning value to variable in this case "somevar"

MySQL update CASE WHEN/THEN/ELSE

Try this

UPDATE `table` SET `uid` = CASE
    WHEN id = 1 THEN 2952
    WHEN id = 2 THEN 4925
    WHEN id = 3 THEN 1592
    ELSE `uid`
    END
WHERE id  in (1,2,3)

Rethrowing exceptions in Java without losing the stack trace

public int read(byte[] a) throws IOException {
    try {
        return in.read(a);
    } catch (final Throwable t) {
        /* can do something here, like  in=null;  */
        throw t;
    }
}

This is a concrete example where the method throws an IOException. The final means t can only hold an exception thrown from the try block. Additional reading material can be found here and here.

jQuery rotate/transform

Why not just use, toggleClass on click?

js:

$(this).toggleClass("up");

css:

button.up {
    -webkit-transform: rotate(180deg);
       -moz-transform: rotate(180deg);
        -ms-transform: rotate(180deg);
         -o-transform: rotate(180deg);
            transform: rotate(180deg);
               /* IE6–IE9 */
               filter: progid:DXImageTransform.Microsoft.Matrix(M11=0.9914448613738104, M12=-0.13052619222005157,M21=0.13052619222005157, M22=0.9914448613738104, sizingMethod='auto expand');
                 zoom: 1;
    }

you can also add this to the css:

button{
        -webkit-transition: all 500ms ease-in-out;
        -moz-transition: all 500ms ease-in-out;
        -o-transition: all 500ms ease-in-out;
        -ms-transition: all 500ms ease-in-out;
}

which will add the animation.

PS...

to answer your original question:

you said that it rotates but never stops. When using set timeout you need to make sure you have a condition that will not call settimeout or else it will run forever. So for your code:

<script type="text/javascript">
    $(function() {
     var $elie = $("#bkgimg");
     rotate(0);
     function rotate(degree) {

      // For webkit browsers: e.g. Chrome
    $elie.css({ WebkitTransform: 'rotate(' + degree + 'deg)'});
      // For Mozilla browser: e.g. Firefox
    $elie.css({ '-moz-transform': 'rotate(' + degree + 'deg)'});


    /* add a condition here for the extremity */ 
    if(degree < 180){
      // Animate rotation with a recursive call
      setTimeout(function() { rotate(++degree); },65);
     }
    }
    });
    </script>

How to convert local time string to UTC?

import time

import datetime

def Local2UTC(LocalTime):

    EpochSecond = time.mktime(LocalTime.timetuple())
    utcTime = datetime.datetime.utcfromtimestamp(EpochSecond)

    return utcTime

>>> LocalTime = datetime.datetime.now()

>>> UTCTime = Local2UTC(LocalTime)

>>> LocalTime.ctime()

'Thu Feb  3 22:33:46 2011'

>>> UTCTime.ctime()

'Fri Feb  4 05:33:46 2011'

How to get the name of a class without the package?

The following function will work in JDK version 1.5 and above.

public String getSimpleName()

How to change or add theme to Android Studio?

File->Settings->Appearance & Behavior-> Appearance and In theme select Darcula and apply dark background theme editor.

BigDecimal setScale and round

One important point that is alluded to but not directly addressed is the difference between "precision" and "scale" and how they are used in the two statements. "precision" is the total number of significant digits in a number. "scale" is the number of digits to the right of the decimal point.

The MathContext constructor only accepts precision and RoundingMode as arguments, and therefore scale is never specified in the first statement.

setScale() obviously accepts scale as an argument, as well as RoundingMode, however precision is never specified in the second statement.

If you move the decimal point one place to the right, the difference will become clear:

// 1.
new BigDecimal("35.3456").round(new MathContext(4, RoundingMode.HALF_UP));
//result = 35.35
// 2.
new BigDecimal("35.3456").setScale(4, RoundingMode.HALF_UP);
// result = 35.3456

Image Greyscale with CSS & re-color on mouse-over?

I use the following code on http://www.diagnomics.com/

Smooth transition from b/w to color with magnifying effect (scale)

    img.color_flip {
      filter: url(filters.svg#grayscale); /* Firefox 3.5+ */
      filter: gray; /* IE5+ */
      -webkit-filter: grayscale(1); /* Webkit Nightlies & Chrome Canary */
      -webkit-transition: all .5s ease-in-out;
    }

    img.color_flip:hover {
      filter: none;
      -webkit-filter: grayscale(0);
      -webkit-transform: scale(1.1);
    }

How to change options of <select> with jQuery?

You can remove the existing options by using the empty method, and then add your new options:

var option = $('<option></option>').attr("value", "option value").text("Text");
$("#selectId").empty().append(option);

If you have your new options in an object you can:

var newOptions = {"Option 1": "value1",
  "Option 2": "value2",
  "Option 3": "value3"
};

var $el = $("#selectId");
$el.empty(); // remove old options
$.each(newOptions, function(key,value) {
  $el.append($("<option></option>")
     .attr("value", value).text(key));
});

Edit: For removing the all the options but the first, you can use the :gt selector, to get all the option elements with index greater than zero and remove them:

$('#selectId option:gt(0)').remove(); // remove all options, but not the first 

Xcode 4 - "Valid signing identity not found" error on provisioning profiles on a new Macintosh install

I had this problem because the iOS Development Certificate associated with the provisioning profile was not in my keychain. I had reinstalled OSX and this was the result. I did the following:

  • developer.apple.com under Certificates, Identifiers & Profiles
  • select the corresponding (and valid) iOS Development Certificate, Download it
  • double click the downloaded file, it gets added to the keychain
  • errors in organizer go away

If you don't have a valid cert, generate a new one and make a new provisioning profile with it.

comparing elements of the same array in java

for (int i = 0; i < a.length; i++) {
    for (int k = 0; k < a.length; k++) {
        if (a[i] != a[k]) {
            System.out.println(a[i] + " not the same with  " + a[k + 1] + "\n");
        }
    }
}

You can start from k=1 & keep "a.length-1" in outer for loop, in order to reduce two comparisions,but that doesnt make any significant difference.

Trim characters in Java

I don't think there is any built in function to trim based on a passed in string. Here is a small example of how to do this. This is not likely the most efficient solution, but it is probably fast enough for most situations, evaluate and adapt to your needs. I recommend testing performance and optimizing as needed for any code snippet that will be used regularly. Below, I've included some timing information as an example.

public String trim( String stringToTrim, String stringToRemove )
{
    String answer = stringToTrim;

    while( answer.startsWith( stringToRemove ) )
    {
        answer = answer.substring( stringToRemove.length() );
    }

    while( answer.endsWith( stringToRemove ) )
    {
        answer = answer.substring( 0, answer.length() - stringToRemove.length() );
    }

    return answer;
}

This answer assumes that the characters to be trimmed are a string. For example, passing in "abc" will trim out "abc" but not "bbc" or "cba", etc.

Some performance times for running each of the following 10 million times.

" mile ".trim(); runs in 248 ms included as a reference implementation for performance comparisons.

trim( "smiles", "s" ); runs in 547 ms - approximately 2 times as long as java's String.trim() method.

"smiles".replaceAll("s$|^s",""); runs in 12,306 ms - approximately 48 times as long as java's String.trim() method.

And using a compiled regex pattern Pattern pattern = Pattern.compile("s$|^s"); pattern.matcher("smiles").replaceAll(""); runs in 7,804 ms - approximately 31 times as long as java's String.trim() method.

Rename computer and join to domain in one step with PowerShell

If you create the machine account on the DC first, then you can change the name and join the domain in one reboot.

Retain precision with double in Java

When you input a double number, for example, 33.33333333333333, the value you get is actually the closest representable double-precision value, which is exactly:

33.3333333333333285963817615993320941925048828125

Dividing that by 100 gives:

0.333333333333333285963817615993320941925048828125

which also isn't representable as a double-precision number, so again it is rounded to the nearest representable value, which is exactly:

0.3333333333333332593184650249895639717578887939453125

When you print this value out, it gets rounded yet again to 17 decimal digits, giving:

0.33333333333333326

Is there a /dev/null on Windows?

According to this message on the GCC mailing list, you can use the file "nul" instead of /dev/null:

#include <stdio.h>

int main ()
{
    FILE* outfile = fopen ("/dev/null", "w");
    if (outfile == NULL)
    {
        fputs ("could not open '/dev/null'", stderr);
    }
    outfile = fopen ("nul", "w");
    if (outfile == NULL)
    {
        fputs ("could not open 'nul'", stderr);
    }

    return 0;
}

(Credits to Danny for this code; copy-pasted from his message.)

You can also use this special "nul" file through redirection.

htaccess Access-Control-Allow-Origin

In Zend Framework 2.0 i had this problem. Can be solved in two way .htaccess or php header i prefer .htaccess so i modified .htaccess from:

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^.*$ index.php [NC,L]

to

RewriteEngine On

<IfModule mod_headers.c>
    Header set Access-Control-Allow-Origin "*"
</IfModule>

RewriteCond %{REQUEST_FILENAME} -s [OR]
RewriteCond %{REQUEST_FILENAME} -l [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^.*$ - [NC,L]
RewriteRule ^.*$ index.php [NC,L]

and it start to work

How to show android checkbox at right side?

You can do

<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="right|center"//or "center_vertical" for center text
android:layoutDirection="rtl"
android:text="hello" />

Following line is enough

android:layoutDirection="rtl"

How to change resolution (DPI) of an image?

It's simply a matter of scaling the image width and height up by the correct ratio. Not all images formats support a DPI metatag, and when they do, all they're telling your graphics software to do is divide the image by the ratio supplied.

For example, if you export a 300dpi image from Photoshop to a JPEG, the image will appear to be very large when viewed in your picture viewing software. This is because the DPI information isn't supported in JPEG and is discarded when saved. This means your picture viewer doesn't know what ratio to divide the image by and instead displays the image at at 1:1 ratio.

To get the ratio you need to scale the image by, see the code below. Just remember, this will stretch the image, just like it would in Photoshop. You're essentially quadrupling the size of the image so it's going to stretch and may produce artifacts.

Pseudo code

ratio = 300.0 / 72.0   // 4.167
image.width * ratio
image.height * ratio

Is Laravel really this slow?

I know this is a little old question, but things changed. Laravel isn't that slow. It's, as mentioned, synced folders are slow. However, on Windows 10 I wasn't able to use rsync. I tried both cygwin and minGW. It seems like rsync is incompatible with git for windows's version of ssh.

Here is what worked for me: NFS.

Vagrant docs says:

NFS folders do not work on Windows hosts. Vagrant will ignore your request for NFS synced folders on Windows.

This isn't true anymore. We can use vagrant-winnfsd plugin nowadays. It's really simple to install:

  1. Execute vagrant plugin install vagrant-winnfsd
  2. Change in your Vagrantfile: config.vm.synced_folder ".", "/vagrant", type: "nfs"
  3. Add to Vagrantfile: config.vm.network "private_network", type: "dhcp"

That's all I needed to make NFS work. Laravel response time decreased from 500ms to 100ms for me.

How to read strings from a Scanner in a Java console application?

Replace:

System.out.println("Enter EmployeeName:");
                 ename=(scanner.next());

with:

System.out.println("Enter EmployeeName:");
                 ename=(scanner.nextLine());

This is because next() grabs only the next token, and the space acts as a delimiter between the tokens. By this, I mean that the scanner reads the input: "firstname lastname" as two separate tokens. So in your example, ename would be set to firstname and the scanner is attempting to set the supervisorId to lastname

Getting a timestamp for today at midnight?

_x000D_
_x000D_
function getTodaysTimeStamp() {_x000D_
  const currentTimeStamp = Math.round(Date.now() / 1000);_x000D_
  const startOfDay = currentTimeStamp - (currentTimeStamp % 86400);_x000D_
  return { startOfDay, endOfDay: startOfDay + 86400 - 1 };_x000D_
}_x000D_
_x000D_
// starts from sunday_x000D_
function getThisWeeksTimeStamp() {_x000D_
  const currentTimeStamp = Math.round(Date.now() / 1000);_x000D_
  const currentDay = new Date(currentTimeStamp * 1000);_x000D_
  const startOfWeek = currentTimeStamp - (currentDay.getDay() * 86400) - (currentTimeStamp % 86400);_x000D_
  return { startOfWeek, endOfWeek: startOfWeek + 7 * 86400 - 1 };_x000D_
}_x000D_
_x000D_
_x000D_
function getThisMonthsTimeStamp() {_x000D_
  const currentTimeStamp = Math.round(Date.now() / 1000);_x000D_
  const currentDay = new Date(currentTimeStamp * 1000);_x000D_
  const startOfMonth = currentTimeStamp - ((currentDay.getDate() - 1) * 86400) - (currentTimeStamp % 86400);_x000D_
  const currentMonth = currentDay.getMonth() + 1;_x000D_
  let daysInMonth = 0;_x000D_
  if (currentMonth === 2) daysInMonth = 28;_x000D_
  else if ([1, 3, 5, 7, 8, 10, 12].includes(currentMonth)) daysInMonth = 31;_x000D_
  else daysInMonth = 30;_x000D_
  return { startOfMonth, endOfMonth: startOfMonth + daysInMonth * 86400 - 1 };_x000D_
}_x000D_
_x000D_
_x000D_
console.log(getTodaysTimeStamp());_x000D_
console.log(getThisWeeksTimeStamp());_x000D_
console.log(getThisMonthsTimeStamp());
_x000D_
_x000D_
_x000D_

Are PostgreSQL column names case-sensitive?

Identifiers (including column names) that are not double-quoted are folded to lower case in PostgreSQL. Column names that were created with double-quotes and thereby retained upper-case letters (and/or other syntax violations) have to be double-quoted for the rest of their life:

"first_Name"

Values (string literals / constants) are enclosed in single quotes:

'xyz'

So, yes, PostgreSQL column names are case-sensitive (when double-quoted):

SELECT * FROM persons WHERE "first_Name" = 'xyz';

Read the manual on identifiers here.

My standing advice is to use legal, lower-case names exclusively so double-quoting is not needed.

Setting the Textbox read only property to true using JavaScript

document.getElementById('textbox-id').readOnly=true should work

How do you change the character encoding of a postgres database?

To change the encoding of your database:

  1. Dump your database
  2. Drop your database,
  3. Create new database with the different encoding
  4. Reload your data.

Make sure the client encoding is set correctly during all this.

Source: http://archives.postgresql.org/pgsql-novice/2006-03/msg00210.php

Setting background-image using jQuery CSS property

$('myObject').css({'background-image': 'url(imgUrl)',});

SQL select * from column where year = 2010

NB: Should you want the year to be based on some reference date, the code below calculates the dates for the between statement:

declare @referenceTime datetime = getutcdate()
select *
from myTable
where SomeDate 
    between dateadd(year, year(@referenceTime) - 1900, '01-01-1900')                        --1st Jan this year (midnight)
    and dateadd(millisecond, -3, dateadd(year, year(@referenceTime) - 1900, '01-01-1901'))  --31st Dec end of this year (just before midnight of the new year)

Similarly, if you're using a year value, swapping year(@referenceDate) for your reference year's value will work

declare @referenceYear int = 2010
select *
from myTable
where SomeDate 
    between dateadd(year,@referenceYear - 1900, '01-01-1900')                       --1st Jan this year (midnight)
    and dateadd(millisecond, -3, dateadd(year,@referenceYear - 1900, '01-01-1901')) --31st Dec end of this year (just before midnight of the new year)

Git: cannot checkout branch - error: pathspec '...' did not match any file(s) known to git

I my case I run "git fetch" before "git branch ...:, but obtained the same error. Then I analyzed it and found error in my branch name. Fixed it and switch to branch successfully.

C - freeing structs

This way you only need to free the structure because the fields are arrays with static sizes which will be allocated as part of the structure. This is also the reason that the addresses you see match: the array is the first thing in that structure. If you declared the fields as char * you would have to manually malloc and free them as well.

setTimeout / clearTimeout problems

The problem is that the timer variable is local, and its value is lost after each function call.

You need to persist it, you can put it outside the function, or if you don't want to expose the variable as global, you can store it in a closure, e.g.:

var endAndStartTimer = (function () {
  var timer; // variable persisted here
  return function () {
    window.clearTimeout(timer);
    //var millisecBeforeRedirect = 10000; 
    timer = window.setTimeout(function(){alert('Hello!');},10000); 
  };
})();

Android: where are downloaded files saved?

In my experience all the files which i have downloaded from internet,gmail are stored in

/sdcard/download

on ics

/sdcard/Download

You can access it using

Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);

JavaScript by reference vs. by value

My understanding is that this is actually very simple:

  • Javascript is always pass by value, but when a variable refers to an object (including arrays), the "value" is a reference to the object.
  • Changing the value of a variable never changes the underlying primitive or object, it just points the variable to a new primitive or object.
  • However, changing a property of an object referenced by a variable does change the underlying object.

So, to work through some of your examples:

function f(a,b,c) {
    // Argument a is re-assigned to a new value.
    // The object or primitive referenced by the original a is unchanged.
    a = 3;
    // Calling b.push changes its properties - it adds
    // a new property b[b.length] with the value "foo".
    // So the object referenced by b has been changed.
    b.push("foo");
    // The "first" property of argument c has been changed.
    // So the object referenced by c has been changed (unless c is a primitive)
    c.first = false;
}

var x = 4;
var y = ["eeny", "miny", "mo"];
var z = {first: true};
f(x,y,z);
console.log(x, y, z.first); // 4, ["eeny", "miny", "mo", "foo"], false

Example 2:

var a = ["1", "2", {foo:"bar"}];
var b = a[1]; // b is now "2";
var c = a[2]; // c now references {foo:"bar"}
a[1] = "4";   // a is now ["1", "4", {foo:"bar"}]; b still has the value
              // it had at the time of assignment
a[2] = "5";   // a is now ["1", "4", "5"]; c still has the value
              // it had at the time of assignment, i.e. a reference to
              // the object {foo:"bar"}
console.log(b, c.foo); // "2" "bar"

How do I wrap text in a pre tag?

I've found that skipping the pre tag and using white-space: pre-wrap on a div is a better solution.

 <div style="white-space: pre-wrap;">content</div>

python tuple to dict

>>> dict([('hi','goodbye')])
{'hi': 'goodbye'}

Or:

>>> [ dict([i]) for i in (('CSCO', 21.14), ('CSCO', 21.14), ('CSCO', 21.14), ('CSCO', 21.14)) ]
[{'CSCO': 21.14}, {'CSCO': 21.14}, {'CSCO': 21.14}, {'CSCO': 21.14}]

How to determine a Python variable's type?

You may be looking for the type() built-in function.

See the examples below, but there's no "unsigned" type in Python just like Java.

Positive integer:

>>> v = 10
>>> type(v)
<type 'int'>

Large positive integer:

>>> v = 100000000000000
>>> type(v)
<type 'long'>

Negative integer:

>>> v = -10
>>> type(v)
<type 'int'>

Literal sequence of characters:

>>> v = 'hi'
>>> type(v)
<type 'str'>

Floating point integer:

>>> v = 3.14159
>>> type(v)
<type 'float'>

Best way to test for a variable's existence in PHP; isset() is clearly broken

I'm going to add a quick two cents to this. One reason this issue is confusing is because this scenario seems to return the same result with error reporting not on full:

$a = null;
var_dump($a); // NULL
var_dump($b); // NULL

You could assume from this result that the difference between $a = null and not defining $b at all is nothing.

Crank error reporting up:

NULL

Notice: Undefined variable: b in xxx on line n
NULL

Note: it threw an undefined variable error, but the output value of var_dump is still NULL.

PHP obviously does have an internal ability to distinguish between a null variable and an undefined variable. It seems to me that there should be a built in function to check for this.

I think the accepted answer is good for the most part, but if I was going to implement it I would write a wrapper for it. As previously mentioned in this answer, I have to agree that I haven't actually encountered a situation where this has been a problem. I seem to almost always end up in a scenario where my variables are either set and defined, or they aren't (undefined, unset, null, blank, etc). Not to say that a situation like this won't occur in future, but as it seems to be quite a unique issue I'm not surprised that the PHP devs haven't bothered to put this in.

Check if any type of files exist in a directory using BATCH script

To check if a folder contains at least one file

>nul 2>nul dir /a-d "folderName\*" && (echo Files exist) || (echo No file found)

To check if a folder or any of its descendents contain at least one file

>nul 2>nul dir /a-d /s "folderName\*" && (echo Files exist) || (echo No file found)

To check if a folder contains at least one file or folder.
Note addition of /a option to enable finding of hidden and system files/folders.

dir /b /a "folderName\*" | >nul findstr "^" && (echo Files and/or Folders exist) || (echo No File or Folder found)

To check if a folder contains at least one folder

dir /b /ad "folderName\*" | >nul findstr "^" && (echo Folders exist) || (echo No folder found)

Accessing nested JavaScript objects and arrays by string path

AngularJS

Speigg's approach is very neat and clean, though I found this reply while searching for the solution of accessing AngularJS $scope properties by string path and with a little modification it does the job:

$scope.resolve = function( path, obj ) {
    return path.split('.').reduce( function( prev, curr ) {
        return prev[curr];
    }, obj || this );
}

Just place this function in your root controller and use it any child scope like this:

$scope.resolve( 'path.to.any.object.in.scope')

Bootstrap visible and hidden classes not working properly

Your .mobile div has the following styles on it:

.mobile {
    display: none !important;
    visibility: hidden !important;
}

Therefore you need to override the visibility property with visible in addition to overriding the display property with block. Like so:

.visible-sm {
    display: block !important;
    visibility: visible !important;
}

File Upload without Form

Basing on this tutorial, here a very basic way to do that:

$('your_trigger_element_selector').on('click', function(){    
    var data = new FormData();
    data.append('input_file_name', $('your_file_input_selector').prop('files')[0]);
    // append other variables to data if you want: data.append('field_name_x', field_value_x);

    $.ajax({
        type: 'POST',               
        processData: false, // important
        contentType: false, // important
        data: data,
        url: your_ajax_path,
        dataType : 'json',  
        // in PHP you can call and process file in the same way as if it was submitted from a form:
        // $_FILES['input_file_name']
        success: function(jsonData){
            ...
        }
        ...
    }); 
});

Don't forget to add proper error handling

How to check if X server is running?

One trick I use to tell if X is running is:

telnet 127.0.0.1 6000

If it connects, you have an X server running and its accepting inbound TCP connections (not usually the default these days)....

How to check if a row exists in MySQL? (i.e. check if an email exists in MySQL)

There are multiple ways to check if a value exists in the database. Let me demonstrate how this can be done properly with PDO and mysqli.

PDO

PDO is the simpler option. To find out whether a value exists in the database you can use prepared statement and fetchColumn(). There is no need to fetch any data so we will only fetch 1 if the value exists.

<?php

// Connection code. 
$options = [
    \PDO::ATTR_ERRMODE            => \PDO::ERRMODE_EXCEPTION,
    \PDO::ATTR_EMULATE_PREPARES   => false,
];
$pdo = new \PDO('mysql:host=localhost;port=3306;dbname=test;charset=utf8mb4', 'testuser', 'password', $options);

// Prepared statement
$stmt = $pdo->prepare('SELECT 1 FROM tblUser WHERE email=?');
$stmt->execute([$_POST['email']]);
$exists = $stmt->fetchColumn(); // either 1 or null

if ($exists) {
    echo 'Email exists in the database.';
} else {
    // email doesn't exist yet
}

For more examples see: How to check if email exists in the database?

MySQLi

As always mysqli is a little more cumbersome and more restricted, but we can follow a similar approach with prepared statement.

<?php

// Connection code
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);
$mysqli = new \mysqli('localhost', 'testuser', 'password', 'test');
$mysqli->set_charset('utf8mb4');

// Prepared statement
$stmt = $mysqli->prepare('SELECT 1 FROM tblUser WHERE email=?');
$stmt->bind_param('s', $_POST['email']);
$stmt->execute();
$exists = (bool) $stmt->get_result()->fetch_row(); // Get the first row from result and cast to boolean

if ($exists) {
    echo 'Email exists in the database.';
} else {
    // email doesn't exist yet
}

Instead of casting the result row(which might not even exist) to boolean, you can also fetch COUNT(1) and read the first item from the first row using fetch_row()[0]

For more examples see: How to check whether a value exists in a database using mysqli prepared statements

Minor remarks

  • If someone suggests you to use mysqli_num_rows(), don't listen to them. This is a very bad approach and could lead to performance issues if misused.
  • Don't use real_escape_string(). This is not meant to be used as a protection against SQL injection. If you use prepared statements correctly you don't need to worry about any escaping.
  • If you want to check if a row exists in the database before you try to insert a new one, then it is better not to use this approach. It is better to create a unique key in the database and let it throw an exception if a duplicate value exists.

FFT in a single C-file

Your best bet is KissFFT - as its name implies it's simple, but it's still quite respectably fast, and a lot more lightweight than FFTW. It's also free, wheras FFTW requires a hefty licence fee if you want to include it in a commercial product.

Master Page Weirdness - "Content controls have to be top-level controls in a content page or a nested master page that references a master page."

Just got this problem. It was because we had a tag ending with double slashes:

<//asp:HyperLink>

How to assign a value to a TensorFlow variable?

So i had a adifferent case where i needed to assign values before running a session, So this was the easiest way to do that:

other_variable = tf.get_variable("other_variable", dtype=tf.int32,
  initializer=tf.constant([23, 42]))

here i'm creating a variable as well as assigning it values at the same time

Spring MVC - HttpMediaTypeNotAcceptableException

I had the same issue, but i had figured out that basically what happens when spring is trying to render the response it will try to serialize it according to the media type you have specified and by using getter and setter methods in your class

before my class used to look like below

public class MyRestResponse{
    private String message;
}

solution looks like below

public class MyRestResponse{
    private String message;
    public void setMessage(String msg){
        this.message = msg;
    }
    public String getMessage(){
        return this.message;
    }
}

that's how it worked for me

Excel cell value as string won't store as string

Use Range("A1").Text instead of .Value

post comment edit:
Why?
Because the .Text property of Range object returns what is literally visible in the spreadsheet, so if you cell displays for example i100l:25he*_92 then <- Text will return exactly what it in the cell including any formatting.
The .Value and .Value2 properties return what's stored in the cell under the hood excluding formatting. Specially .Value2 for date types, it will return the decimal representation.

If you want to dig deeper into the meaning and performance, I just found this article which seems like a good guide

another edit
Here you go @Santosh
type in (MANUALLY) the values from the DEFAULT (col A) to other columns
Do not format column A at all
Format column B as Text
Format column C as Date[dd/mm/yyyy]
Format column D as Percentage
Dont Format column A, Format B as TEXT, C as Date, D as Percentage
now,
paste this code in a module

Sub main()

    Dim ws As Worksheet, i&, j&
    Set ws = Sheets(1)
    For i = 3 To 7
        For j = 1 To 4
            Debug.Print _
                    "row " & i & vbTab & vbTab & _
                    Cells(i, j).Text & vbTab & _
                    Cells(i, j).Value & vbTab & _
                    Cells(i, j).Value2
        Next j
    Next i
End Sub

and Analyse the output! Its really easy and there isn't much more i can do to help :)

            .TEXT              .VALUE             .VALUE2
row 3       hello             hello               hello
row 3       hello             hello               hello
row 3       hello             hello               hello
row 3       hello             hello               hello
row 4       1                 1                   1
row 4       1                 1                   1
row 4       01/01/1900        31/12/1899          1
row 4       1.00%             0.01                0.01
row 5       helo1$$           helo1$$             helo1$$
row 5       helo1$$           helo1$$             helo1$$
row 5       helo1$$           helo1$$             helo1$$
row 5       helo1$$           helo1$$             helo1$$
row 6       63                63                  63
row 6       =7*9              =7*9                =7*9
row 6       03/03/1900        03/03/1900          63
row 6       6300.00%          63                  63
row 7       29/05/2013        29/05/2013          41423
row 7       29/05/2013        29/05/2013          29/05/2013
row 7       29/05/2013        29/05/2013          41423
row 7       29/05/2013%       29/05/2013%         29/05/2013%

conversion from string to json object android

Remove the slashes:

String json = {"phonetype":"N95","cat":"WP"};

try {

    JSONObject obj = new JSONObject(json);

    Log.d("My App", obj.toString());

} catch (Throwable t) {
    Log.e("My App", "Could not parse malformed JSON: \"" + json + "\"");
}

Reference - What does this regex mean?

The Stack Overflow Regular Expressions FAQ

See also a lot of general hints and useful links at the tag details page.


Online tutorials

Quantifiers

Character Classes

Escape Sequences

Anchors

(Also see "Flavor-Specific Information ? Java ? The functions in Matcher")

Groups

Lookarounds

Modifiers

Other:

Common Tasks

Advanced Regex-Fu

Flavor-Specific Information

(Except for those marked with *, this section contains non-Stack Overflow links.)

General information

(Links marked with * are non-Stack Overflow links.)

Examples of regex that can cause regex engine to fail

Tools: Testers and Explainers

(This section contains non-Stack Overflow links.)

Maximum Java heap size of a 32-bit JVM on a 64-bit OS

On Solaris the limit has been about 3.5 GB since Solaris 2.5. (about 10 years ago)

How to get Time from DateTime format in SQL?

The simplest way to get the time from datetime without millisecond stack is:

SELECT convert(time(0),getDate())

Easiest way to toggle 2 classes in jQuery

I've made a jQuery plugin for working DRY:

$.fn.toggle2classes = function(class1, class2){
  if( !class1 || !class2 )
    return this;

  return this.each(function(){
    var $elm = $(this);

    if( $elm.hasClass(class1) || $elm.hasClass(class2) )
      $elm.toggleClass(class1 +' '+ class2);

    else
      $elm.addClass(class1);
  });
};

You can just try it here, copy and run this in the console and then try:

$('body').toggle2classes('a', 'b');

How to use Ajax.ActionLink?

Sure, a very similar question was asked before. Set the controller for ajax requests:

public ActionResult Show()
{
    if (Request.IsAjaxRequest()) 
    {
        return PartialView("Your_partial_view", new Model());
    }
    else 
    {
        return View();
    }
}

Set the action link as wanted:

@Ajax.ActionLink("Show", 
                 "Show", 
                 null, 
                 new AjaxOptions { HttpMethod = "GET", 
                 InsertionMode = InsertionMode.Replace, 
                 UpdateTargetId = "dialog_window_id", 
                 OnComplete = "your_js_function();" })

Note that I'm using Razor view engine, and that your AjaxOptions may vary depending on what you want. Finally display it on a modal window. The jQuery UI dialog is suggested.

Finding duplicate values in a SQL table

 select emp.ename, emp.empno, dept.loc 
          from emp
 inner join dept 
          on dept.deptno=emp.deptno
 inner join
    (select ename, count(*) from
    emp
    group by ename, deptno
    having count(*) > 1)
 t on emp.ename=t.ename order by emp.ename
/

Add a properties file to IntelliJ's classpath

Perhaps this is a bit off-topic, seeing as the question has already been answered, but I have experienced a similar problem. In my case only some of the unit test resources were copied to the output folder upon compilation. My persistence.xml in the META-INF folder got copied but nothing else.

In the end I "solved" the problem by renaming the problematic files, rebuiling the project and then changing the file names back to the original ones. Do not ask me why this worked but it did. My best guess is that, somehow, my IntelliJ project had gotten a bit out of sync with the file system and the renaming operation triggered some kind of internal "resource rescan".

How to copy text from a div to clipboard

Made a modification to the solutions, so it will work with multiple divs based on class instead of specific IDs. For example, if you have multiple blocks of code. This assumes that the div class is set to "code".

<script>
        $( document ).ready(function() {
            $(".code").click(function(event){
                var range = document.createRange();
                range.selectNode(this);
                window.getSelection().removeAllRanges(); // clear current selection
                window.getSelection().addRange(range); // to select text
                document.execCommand("copy");
                window.getSelection().removeAllRanges();// to deselect
            });
        });
    </script>

How do you create a toggle button?

You can use the "active" pseudoclass (it won't work on IE6, though, for elements other than links)

a:active
{
    ...desired style here...
}

How to replace negative numbers in Pandas Data Frame by zero

With lambda function

df['column'] = df['column'].apply(lambda x : x if x > 0 else 0)

Any reason to prefer getClass() over instanceof when generating .equals()?

If you use instanceof, making your equals implementation final will preserve the symmetry contract of the method: x.equals(y) == y.equals(x). If final seems restrictive, carefully examine your notion of object equivalence to make sure that your overriding implementations fully maintain the contract established by the Object class.

Array vs ArrayList in performance

When deciding to use Array or ArrayList, your first instinct really shouldn't be worrying about performance, though they do perform differently. You first concern should be whether or not you know the size of the Array before hand. If you don't, naturally you would go with an array list, just for functionality.

React Error: Target Container is not a DOM Element

For those that implemented react js in some part of the website and encounter this issue. Just add a condition to check if the element exist on that page before you render the react component.

<div id="element"></div>

...

const someElement = document.getElementById("element")
    
if(someElement) {
  ReactDOM.render(<Yourcomponent />, someElement)
}

How to fix Error: laravel.log could not be opened?

For all Centos 7 users on a Laravel context, there is no need to disable Selinux, just run these commands:

yum install policycoreutils-python -y # might not be necessary, try the below first

semanage fcontext -a -t httpd_sys_rw_content_t "/var/www/html/laravel/storage(/.*)?" # add a new httpd read write content to sellinux for the specific folder, -m for modify
semanage fcontext -a -t httpd_sys_rw_content_t "/var/www/html/laravel/bootstrap/cache(/.*)?" # same as the above for b/cache

restorecon -Rv /var/www/html/ # this command is very important to, it's like a restart to apply the new rules

Lastly, make sure your hosts, ips and virtual hosts are all correctly for remote accessing.

Selinux is intended to restrict access even to root users, so only the necessary stuff might be accessed, at least on a generalist overview, it's extra security, disabling it is not a good practise, there are many links to learn Selinux, but for this case it is not even required.

Create an array with same element repeated multiple times

_x000D_
_x000D_
var finalAry = [..."2".repeat(5).split("")].map(Number);_x000D_
console.log(finalAry);
_x000D_
_x000D_
_x000D_

C# DLL config file

Seems like this config files are really confusing to clarify as their behaviour changes from the dev environment to deployment. Apparently a DLL can have its own config file, but once you copy and paste the dll (together with their config file) elsewhere, the whole thing stopped working. The only solution is to manually merge the app.config files into a single file, which will only be used by the exec. For e.g. myapp.exe will have a myapp.exe.config file that contains all settings for all dlls used by myapp.exe. I'm using VS 2008.

Create a tar.xz in one command

Use the -J compression option for xz. And remember to man tar :)

tar cfJ <archive.tar.xz> <files>

Edit 2015-08-10:

If you're passing the arguments to tar with dashes (ex: tar -cf as opposed to tar cf), then the -f option must come last, since it specifies the filename (thanks to @A-B-B for pointing that out!). In that case, the command looks like:

tar -cJf <archive.tar.xz> <files>

Encrypt Password in Configuration Files?

Try using ESAPIs Encryption methods. Its easy to configure and you can also easily change your keys.

http://owasp-esapi-java.googlecode.com/svn/trunk_doc/latest/org/owasp/esapi/Encryptor.html

You

1)encrypt 2)decrypt 3)sign 4)unsign 5)hashing 6)time based signatures and much more with just one library.

How do you overcome the HTML form nesting limitation?

I just came up with a nice way of doing it with jquery.

<form name="mainform">    
    <div id="placeholder">
    <div>
</form>

<form id="nested_form" style="position:absolute">
</form>

<script>
   $(document).ready(function(){
      pos = $('#placeholder').position();
      $('#nested_form')
         .css('left', pos.left.toFixed(0)+'px')
         .css('top', pos.top.toFixed(0)+'px');
   });
</script>

Design Documents (High Level and Low Level Design Documents)

High-Level Design (HLD) involves decomposing a system into modules, and representing the interfaces & invocation relationships among modules. An HLD is referred to as software architecture.

LLD, also known as a detailed design, is used to design internals of the individual modules identified during HLD i.e. data structures and algorithms of the modules are designed and documented.

Now, HLD and LLD are actually used in traditional Approach (Function-Oriented Software Design) whereas, in OOAD, the system is seen as a set of objects interacting with each other.

As per the above definitions, a high-level design document will usually include a high-level architecture diagram depicting the components, interfaces, and networks that need to be further specified or developed. The document may also depict or otherwise refer to work flows and/or data flows between component systems.

Class diagrams with all the methods and relations between classes come under LLD. Program specs are covered under LLD. LLD describes each and every module in an elaborate manner so that the programmer can directly code the program based on it. There will be at least 1 document for each module. The LLD will contain - a detailed functional logic of the module in pseudo code - database tables with all elements including their type and size - all interface details with complete API references(both requests and responses) - all dependency issues - error message listings - complete inputs and outputs for a module.

JSON.NET Error Self referencing loop detected for type

People have already talked about [JsonIgnore] being added to the virtual property in the class, for example:

[JsonIgnore]
public virtual Project Project { get; set; }

I will also share another option, [JsonProperty(NullValueHandling = NullValueHandling.Ignore)] which omits the property from serialization only if it is null:

[JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
public virtual Project Project { get; set; }

Get a list of URLs from a site

So, in an ideal world you'd have a spec for all pages in your site. You would also have a test infrastructure that could hit all your pages to test them.

You're presumably not in an ideal world. Why not do this...?

  1. Create a mapping between the well known old URLs and the new ones. Redirect when you see an old URL. I'd possibly consider presenting a "this page has moved, it's new url is XXX, you'll be redirected shortly".

  2. If you have no mapping, present a "sorry - this page has moved. Here's a link to the home page" message and redirect them if you like.

  3. Log all redirects - especially the ones with no mapping. Over time, add mappings for pages that are important.

htaccess remove index.php from url

This will work, use the following code in .htaccess file RewriteEngine On

# Send would-be 404 requests to Craft
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !^/(favicon\.ico|apple-touch-icon.*\.png)$ [NC]
RewriteRule (.+) index.php?p=$1 [QSA,L]

How to export DataTable to Excel

The best and easiest way

private void exportToExcel(DataTable dt)
    {

        /*Set up work book, work sheets, and excel application*/
        Microsoft.Office.Interop.Excel.Application oexcel = new Microsoft.Office.Interop.Excel.Application();
        try
        {
            string path = AppDomain.CurrentDomain.BaseDirectory;
            object misValue = System.Reflection.Missing.Value;
            Microsoft.Office.Interop.Excel.Workbook obook = oexcel.Workbooks.Add(misValue);
            Microsoft.Office.Interop.Excel.Worksheet osheet = new Microsoft.Office.Interop.Excel.Worksheet();


          //  obook.Worksheets.Add(misValue);

            osheet = (Microsoft.Office.Interop.Excel.Worksheet)obook.Sheets["Sheet1"];
            int colIndex = 0;
            int rowIndex = 1;

            foreach (DataColumn dc in dt.Columns)
            {
                colIndex++;
                osheet.Cells[1, colIndex] = dc.ColumnName;
            }
            foreach (DataRow dr in dt.Rows)
            {
                rowIndex++;
                colIndex = 0;

                foreach (DataColumn dc in dt.Columns)
                {
                    colIndex++;
                    osheet.Cells[rowIndex, colIndex] = dr[dc.ColumnName];
                }
            }

            osheet.Columns.AutoFit();
            string filepath = "C:\\Temp\\Book1";

            //Release and terminate excel

            obook.SaveAs(filepath);
            obook.Close();
            oexcel.Quit();
            releaseObject(osheet);

            releaseObject(obook);

            releaseObject(oexcel);
            GC.Collect();
        }
        catch (Exception ex)
        {
            oexcel.Quit();
            log.AddToErrorLog(ex, this.Name);
        }
    }

How to add browse file button to Windows Form using C#

var FD = new System.Windows.Forms.OpenFileDialog();
if (FD.ShowDialog() == System.Windows.Forms.DialogResult.OK) {
    string fileToOpen = FD.FileName;

    System.IO.FileInfo File = new System.IO.FileInfo(FD.FileName);

    //OR

    System.IO.StreamReader reader = new System.IO.StreamReader(fileToOpen);
    //etc
}

how to get the ipaddress of a virtual box running on local machine

Login to virtual machine use below command to check ip address. (anyone will work)

  1. ifconfig
  2. ip addr show

If you used NAT for your virtual machine settings(your machine ip will be 10.0.2.15), then you have to use port forwarding to connect to machine. IP address will be 127.0.0.1

If you used bridged networking/Host only networking, then you will have separate Ip address. Use that IP address to connect virtual machine

MySQL SELECT AS combine two columns into one

You do not need to select the columns separately in order to use them in your CONCAT. Simply remove them, and your query will become:

SELECT FirstName AS First_Name
     , LastName AS Last_Name
     , CONCAT(ContactPhoneAreaCode1, ContactPhoneNumber1) AS Contact_Phone 
  FROM TABLE1

Function to calculate distance between two coordinates

Calculate the Distance between Two Points in javascript

function distance(lat1, lon1, lat2, lon2, unit) {
        var radlat1 = Math.PI * lat1/180
        var radlat2 = Math.PI * lat2/180
        var theta = lon1-lon2
        var radtheta = Math.PI * theta/180
        var dist = Math.sin(radlat1) * Math.sin(radlat2) + Math.cos(radlat1) * Math.cos(radlat2) * Math.cos(radtheta);
        dist = Math.acos(dist)
        dist = dist * 180/Math.PI
        dist = dist * 60 * 1.1515
        if (unit=="K") { dist = dist * 1.609344 }
        if (unit=="N") { dist = dist * 0.8684 }
        return dist
}

For more details refer this: Reference Link

Difference Between Select and SelectMany

It's more clear when the query return a string (an array of char):

For example if the list 'Fruits' contains 'apple'

'Select' returns the string:

Fruits.Select(s=>s) 

[0]: "apple"

'SelectMany' flattens the string:

Fruits.SelectMany(s=>s)

[0]: 97  'a'
[1]: 112 'p'
[2]: 112 'p'
[3]: 108 'l'
[4]: 101 'e'

FlutterError: Unable to load asset

My issue was nested folders.

I had my image in assets/images/logo/xyz.png and thought that - assets/images/ would catch all subfolders.

You have to explicitly add each nested subfolder

Solution: - assets/images/logo/ etc.

Convert an ArrayList to an object array

Something like the standard Collection.toArray(T[]) should do what you need (note that ArrayList implements Collection):

TypeA[] array = a.toArray(new TypeA[a.size()]);

On a side note, you should consider defining a to be of type List<TypeA> rather than ArrayList<TypeA>, this avoid some implementation specific definition that may not really be applicable for your application.

Also, please see this question about the use of a.size() instead of 0 as the size of the array passed to a.toArray(TypeA[])

pip install gives error: Unable to find vcvarsall.bat

The problem here is the line 292 (Using Python 3.4.3 here) in $python_install_prefix/Lib/distutils/msvc9compiler.py which says:

VERSION = get_build_version()

This only checks for the MSVC version that your python was built with. Just replacing this line with your actual Visual Studio version, eg. 12.0 for MSVC2013

VERSION = 12.0

will fix the issue.

UPDATE: Turns out that there is a good reason why this version is hardcoded. MSVC C runtime is not required to be compatible between major versions. Hence when you use a different VS version you might run into runtime problems. So I advise to use VS 2008 (for Python 2.6 up to 3.2) and VS2010 for (Python 3.3 and later) until this issue is sorted out.

Binary compatibility will arrive with VS 2015 (see here) along with Python 3.5 .

For Python 2.7 users Microsoft released a special Microsoft Visual C++ Compiler for Python 2.7 which can be used without installing the whole VS 2008.

Dynamically create checkbox with JQuery from text input

Put a global variable to generate the ids.

<script>
    $(function(){
        // Variable to get ids for the checkboxes
        var idCounter=1;
        $("#btn1").click(function(){
            var val = $("#txtAdd").val();
            $("#divContainer").append ( "<label for='chk_" + idCounter + "'>" + val + "</label><input id='chk_" + idCounter + "' type='checkbox' value='" + val + "' />" );
            idCounter ++;
        });
    });
</script>
<div id='divContainer'></div>
<input type="text" id="txtAdd" /> 
<button id="btn1">Click</button>

updating nodejs on ubuntu 16.04

According to official docs to install node on Debian and Ubuntu based distributions:

node v12 (Old)

curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash -
sudo apt-get install -y nodejs

node v14 (For new users: install this one):

curl -sL https://deb.nodesource.com/setup_14.x | sudo -E bash -
sudo apt-get install -y nodejs

node v15 (Current version):

curl -sL https://deb.nodesource.com/setup_15.x | sudo -E bash -
sudo apt-get install -y nodejs

Other older versions: Just replace the desired version number in the link above.

Optional: install build tools

To compile and install native packages

sudo apt-get install -y build-essential

To update node to the latest version just:

sudo apt update
sudo apt upgrade

To keep npm updated

sudo npm i -g npm

To find out other versions try npm info npm and in versions find your desired version and replace [version-tag] with that version tag in npm i -g npm@[version-tag]

And I also recommend trying yarn instead of npm

How set maximum date in datepicker dialog in android?

private int pYear;
private int pMonth;
private int pDay;
static final int DATE_DIALOG_ID = 0;

/**inside oncreate */
final Calendar c = Calendar.getInstance();
         pYear= c.get(Calendar.YEAR);
         pMonth = c.get(Calendar.MONTH);
         pDay = c.get(Calendar.DAY_OF_MONTH);


 @Override
     protected Dialog onCreateDialog(int id) {
             switch (id) {
             case DATE_DIALOG_ID:
                     return new DatePickerDialog(this,
                             mDateSetListener,
                             pYear, pMonth-1, pDay);
            }

             return null;
     }
     protected void onPrepareDialog(int id, Dialog dialog) {
             switch (id) {
             case DATE_DIALOG_ID:
                     ((DatePickerDialog) dialog).updateDate(pYear, pMonth-1, pDay);
                     break;
             }
     }   
     private DatePickerDialog.OnDateSetListener mDateSetListener =
         new DatePickerDialog.OnDateSetListener() {
         public void onDateSet(DatePicker view, int year, int monthOfYear,
                         int dayOfMonth) {
                // write your code here to get the selected Date
         }
 };

try this it should work. Thanks

JavaScript code for getting the selected value from a combo box

There is an unnecessary hashtag; change the code to this:

var e = document.getElementById("ticket_category_clone").value;

How to get year/month/day from a date object?

var dt = new Date();

dt.getFullYear() + "/" + (dt.getMonth() + 1) + "/" + dt.getDate();

Since month index are 0 based you have to increment it by 1.

Edit

For a complete list of date object functions see

Date

getMonth()

Returns the month (0-11) in the specified date according to local time.

getUTCMonth()

Returns the month (0-11) in the specified date according to universal time.

Push items into mongo array via mongoose

Assuming, var friend = { firstName: 'Harry', lastName: 'Potter' };

There are two options you have:

Update the model in-memory, and save (plain javascript array.push):

person.friends.push(friend);
person.save(done);

or

PersonModel.update(
    { _id: person._id }, 
    { $push: { friends: friend } },
    done
);

I always try and go for the first option when possible, because it'll respect more of the benefits that mongoose gives you (hooks, validation, etc.).

However, if you are doing lots of concurrent writes, you will hit race conditions where you'll end up with nasty version errors to stop you from replacing the entire model each time and losing the previous friend you added. So only go to the former when it's absolutely necessary.

Call-time pass-by-reference has been removed

Only call time pass-by-reference is removed. So change:

call_user_func($func, &$this, &$client ...

To this:

call_user_func($func, $this, $client ...

&$this should never be needed after PHP4 anyway period.

If you absolutely need $client to be passed by reference, update the function ($func) signature instead (function func(&$client) {)

Difference between using Makefile and CMake to compile the code

The statement about CMake being a "build generator" is a common misconception.

It's not technically wrong; it just describes HOW it works, but not WHAT it does.

In the context of the question, they do the same thing: take a bunch of C/C++ files and turn them into a binary.

So, what is the real difference?

  • CMake is much more high-level. It's tailored to compile C++, for which you write much less build code, but can be also used for general purpose build. make has some built-in C/C++ rules as well, but they are useless at best.

  • CMake does a two-step build: it generates a low-level build script in ninja or make or many other generators, and then you run it. All the shell script pieces that are normally piled into Makefile are only executed at the generation stage. Thus, CMake build can be orders of magnitude faster.

  • The grammar of CMake is much easier to support for external tools than make's.

  • Once make builds an artifact, it forgets how it was built. What sources it was built from, what compiler flags? CMake tracks it, make leaves it up to you. If one of library sources was removed since the previous version of Makefile, make won't rebuild it.

  • Modern CMake (starting with version 3.something) works in terms of dependencies between "targets". A target is still a single output file, but it can have transitive ("public"/"interface" in CMake terms) dependencies. These transitive dependencies can be exposed to or hidden from the dependent packages. CMake will manage directories for you. With make, you're stuck on a file-by-file and manage-directories-by-hand level.

You could code up something in make using intermediate files to cover the last two gaps, but you're on your own. make does contain a Turing complete language (even two, sometimes three counting Guile); the first two are horrible and the Guile is practically never used.

To be honest, this is what CMake and make have in common -- their languages are pretty horrible. Here's what comes to mind:

  • They have no user-defined types;
  • CMake has three data types: string, list, and a target with properties. make has one: string;
  • you normally pass arguments to functions by setting global variables.
    • This is partially dealt with in modern CMake - you can set a target's properties: set_property(TARGET helloworld APPEND PROPERTY INCLUDE_DIRECTORIES "${CMAKE_CURRENT_SOURCE_DIR}");
  • referring to an undefined variable is silently ignored by default;

Get the difference between two dates both In Months and days in sql

SELECT   (MONTHS_BETWEEN(date2,date1) +  (datediff(day,date2,date1))/30) as num_months,
datediff(day,date2,date1) as diff_in_days  FROM  dual;

// You should replace date2 with TO_DATE('2012/03/25', 'YYYY/MM/DD')
// You should replace date1 with TO_DATE('2012/01/01', 'YYYY/MM/DD')
// To get you results

What is the preferred syntax for defining enums in JavaScript?

Since 1.8.5 it's possible to seal and freeze the object, so define the above as:

const DaysEnum = Object.freeze({"monday":1, "tuesday":2, "wednesday":3, ...})

or

const DaysEnum = {"monday":1, "tuesday":2, "wednesday":3, ...}
Object.freeze(DaysEnum)

and voila! JS enums.

However, this doesn't prevent you from assigning an undesired value to a variable, which is often the main goal of enums:

let day = DaysEnum.tuesday
day = 298832342 // goes through without any errors

One way to ensure a stronger degree of type safety (with enums or otherwise) is to use a tool like TypeScript or Flow.

Quotes aren't needed but I kept them for consistency.

How do I get rid of the b-prefix in a string in python?

Although the question is very old, I think it may be helpful to who is facing the same problem. Here the texts is a string like below:

text= "b'I posted a new photo to Facebook'"

Thus you can not remove b by encoding it because it's not a byte. I did the following to remove it.

cleaned_text = text.split("b'")[1]

which will give "I posted a new photo to Facebook"

How to import other Python files?

importlib was added to Python 3 to programmatically import a module.

import importlib

moduleName = input('Enter module name:')
importlib.import_module(moduleName)

The .py extension should be removed from moduleName. The function also defines a package argument for relative imports.

In python 2.x:

  • Just import file without the .py extension
  • A folder can be marked as a package, by adding an empty __init__.py file
  • You can use the __import__ function, which takes the module name (without extension) as a string extension
pmName = input('Enter module name:')
pm = __import__(pmName)
print(dir(pm))

Type help(__import__) for more details.

What does 'foo' really mean?

In my opinion every programmer has his or her own "words" that is used every time you need an arbitrary word when programming. For some people it's the first words from a childs song, for other it's names and for other its something completely different. Now for the programmer community there are these "words" as well, and these words are 'foo' and 'bar'. The use of this is that if you have to communicate publicly about programming you don't have to say that you would use arbitratry words, you would simply write 'foo' or 'bar' and every programmer knows that this is just arbitrary words.

DB2 Timestamp select statement

@bhamby is correct. By leaving the microseconds off of your timestamp value, your query would only match on a usagetime of 2012-09-03 08:03:06.000000

If you don't have the complete timestamp value captured from a previous query, you can specify a ranged predicate that will match on any microsecond value for that time:

...WHERE id = 1 AND usagetime BETWEEN '2012-09-03 08:03:06' AND '2012-09-03 08:03:07'

or

...WHERE id = 1 AND usagetime >= '2012-09-03 08:03:06' 
   AND usagetime < '2012-09-03 08:03:07'

Convert HTML string to image

Try the following:

using System;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;

class Program
{
    static void Main(string[] args)
    {
        var source =  @"
        <!DOCTYPE html>
        <html>
            <body>
                <p>An image from W3Schools:</p>
                <img 
                    src=""http://www.w3schools.com/images/w3schools_green.jpg"" 
                    alt=""W3Schools.com"" 
                    width=""104"" 
                    height=""142"">
            </body>
        </html>";
        StartBrowser(source);
        Console.ReadLine();
    }

    private static void StartBrowser(string source)
    {
        var th = new Thread(() =>
        {
            var webBrowser = new WebBrowser();
            webBrowser.ScrollBarsEnabled = false;
            webBrowser.DocumentCompleted +=
                webBrowser_DocumentCompleted;
            webBrowser.DocumentText = source;
            Application.Run();
        });
        th.SetApartmentState(ApartmentState.STA);
        th.Start();
    }

    static void 
        webBrowser_DocumentCompleted(
        object sender, 
        WebBrowserDocumentCompletedEventArgs e)
    {
        var webBrowser = (WebBrowser)sender;
        using (Bitmap bitmap = 
            new Bitmap(
                webBrowser.Width, 
                webBrowser.Height))
        {
            webBrowser
                .DrawToBitmap(
                bitmap, 
                new System.Drawing
                    .Rectangle(0, 0, bitmap.Width, bitmap.Height));
            bitmap.Save(@"filename.jpg", 
                System.Drawing.Imaging.ImageFormat.Jpeg);
        }
    }
}

Note: Credits should go to Hans Passant for his excellent answer on the question WebBrowser Control in a new thread which inspired this solution.

SQL server ignore case in a where expression

No, only using LIKE will not work. LIKE searches values matching exactly your given pattern. In this case LIKE would find only the text 'sOmeVal' and not 'someval'.

A pracitcable solution is using the LCASE() function. LCASE('sOmeVal') gets the lowercase string of your text: 'someval'. If you use this function for both sides of your comparison, it works:

SELECT * FROM myTable WHERE LCASE(myField) LIKE LCASE('sOmeVal')

The statement compares two lowercase strings, so that your 'sOmeVal' will match every other notation of 'someval' (e.g. 'Someval', 'sOMEVAl' etc.).

How to monitor SQL Server table changes by using c#?

Generally, you'd use Service Broker

That is trigger -> queue -> application(s)

Edit, after seeing other answers:

FYI: "Query Notifications" is built on Service broker

Edit2:

More links

svn cleanup: sqlite: database disk image is malformed

Have you seen this post on the subversion site? You could also potentially try validating and "fixing" the database directly as described here. (Note that I'm no expert, I just did a quick google search. May not be related to your issues at all).

Personally, I'd try checking out the repo again and reapplying your changes. Not sure if this is possible though in your case?

To the power of in C?

#include <math.h>


printf ("%d", (int) pow (3, 4));

What is an efficient way to implement a singleton pattern in Java?

Another argument often used against singletons is their testability problems. Singletons are not easily mockable for testing purposes. If this turns out to be a problem, I like to make the following slight modification:

public class SingletonImpl {

    private static SingletonImpl instance;

    public static SingletonImpl getInstance() {
        if (instance == null) {
            instance = new SingletonImpl();
        }
        return instance;
    }

    public static void setInstance(SingletonImpl impl) {
        instance = impl;
    }

    public void a() {
        System.out.println("Default Method");
    }
}

The added setInstance method allows setting a mockup implementation of the singleton class during testing:

public class SingletonMock extends SingletonImpl {

    @Override
    public void a() {
        System.out.println("Mock Method");
    }

}

This also works with early initialization approaches:

public class SingletonImpl {

    private static final SingletonImpl instance = new SingletonImpl();

    private static SingletonImpl alt;

    public static void setInstance(SingletonImpl inst) {
        alt = inst;
    }

    public static SingletonImpl getInstance() {
        if (alt != null) {
            return alt;
        }
        return instance;
    }

    public void a() {
        System.out.println("Default Method");
    }
}

public class SingletonMock extends SingletonImpl {

    @Override
    public void a() {
        System.out.println("Mock Method");
    }

}

This has the drawback of exposing this functionality to the normal application too. Other developers working on that code could be tempted to use the ´setInstance´ method to alter a specific function and thus changing the whole application behaviour, and therefore this method should contain at least a good warning in its javadoc.

Still, for the possibility of mockup-testing (when needed), this code exposure may be an acceptable price to pay.

The network adapter could not establish the connection - Oracle 11g

First check your listener is on or off. Go to net manager then Local -> service naming -> orcl. Then change your HOST NAME and put your PC name. Now go to LISTENER and change the HOST and put your PC name.

regex with space and letters only?

Allowed only characters & spaces. Ex : Jayant Lonari

if (!/^[a-zA-Z\s]+$/.test(NAME)) {
    //Throw Error
}

YouTube URL in Video Tag

Try this solution for the perfectly working

new YouTubeToHtml5();

How to reverse a singly linked list using only two pointers?

#include <stddef.h>

typedef struct Node {
    struct Node *next;
    int data;
} Node;

Node * reverse(Node *cur) {
    Node *prev = NULL;
    while (cur) {
        Node *temp = cur;
        cur = cur->next; // advance cur
        temp->next = prev;
        prev = temp; // advance prev
    }
    return prev;
}

remove double quotes from Json return data using Jquery

For niche needs when you know your data like your example ... this works :

JSON.parse(this_is_double_quoted);

JSON.parse("House");  // for example

List of tuples to dictionary

Just call dict() on the list of tuples directly

>>> my_list = [('a', 1), ('b', 2)]
>>> dict(my_list)
{'a': 1, 'b': 2}

Empty or Null value display in SSRS text boxes

I would disagree with converting it on the server side. If you do that it's going to come back as a string type rather than a date type with all that entails (it will sort as a string for example)

My principle when dealing with dates is to keep them typed as a date for as long as you possibly can.

If your facing a performance bottleneck on the report server there are better ways to handle it than compromising your logic.

Android Facebook style slide

I think that library does not mentioned:

jfeinstein10 / SlidingMenu

github url:https://github.com/jfeinstein10/SlidingMenu

  • works fine with action bar ActionBarSherlock which helps in backward compatibility!
  • Support right slide and not only slide via button!

"string could not resolved" error in Eclipse for C++ (Eclipse can't resolve standard library)

Hello here is a simple solution,

Just go to File -> Convert to a C/C++ Autotools Project Select your project files appropriately.

Inclusions will be added to your project file

How to list all available Kafka brokers in a cluster?

Alternate way using Zk-Client:

If you do not prefer to pass arguments to ./zookeeper-shell.sh and want to see the broker details from Zookeeper CLI, you need to install standalone Zookeeper (As traditional Kafka do not comes up with Jline JAR).

Once you install(unzip) the standalone Zookeeper,then:

  • Run the Zookeeper CLI:
    $ zookeeper/bin/zkCli.sh -server localhost:2181 #Make sure your Broker is already running

  • If it is successful, you can see the Zk client running as:

WATCHER::

WatchedEvent state:SyncConnected type:None path:null
[zk: localhost:2181(CONNECTED) 0]
  • From here you can explore the broker details using various commands:

$ ls /brokers/ids # Gives the list of active brokers
$ ls /brokers/topics #Gives the list of topics
$ get /brokers/ids/0 #Gives more detailed information of the broker id '0'

How do I timestamp every ping result?

On macos you can do

ping --apple-time 127.0.0.1

The output looks like

16:07:11.315419 64 bytes from 127.0.0.1: icmp_seq=0 ttl=64 time=0.064 ms
16:07:12.319933 64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.157 ms
16:07:13.322766 64 bytes from 127.0.0.1: icmp_seq=2 ttl=64 time=0.066 ms
16:07:14.324649 64 bytes from 127.0.0.1: icmp_seq=3 ttl=64 time=0.148 ms
16:07:15.328743 64 bytes from 127.0.0.1: icmp_seq=4 ttl=64 time=0.092 ms

In Python, how do I loop through the dictionary and change the value if it equals something?

for k, v in mydict.iteritems():
    if v is None:
        mydict[k] = ''

In a more general case, e.g. if you were adding or removing keys, it might not be safe to change the structure of the container you're looping on -- so using items to loop on an independent list copy thereof might be prudent -- but assigning a different value at a given existing index does not incur any problem, so, in Python 2.any, it's better to use iteritems.

In Python3 however the code gives AttributeError: 'dict' object has no attribute 'iteritems' error. Use items() instead of iteritems() here.

Refer to this post.

How can I easily view the contents of a datatable or dataview in the immediate window

I've not tried it myself, but Visual Studio 2005 (and later) support the concept of Debugger Visualizers. This allows you to customize how an object is shown in the IDE. Check out this article for more details.

http://davidhayden.com/blog/dave/archive/2005/12/26/2645.aspx

Aggregate multiple columns at once

You could try:

agg <- aggregate(list(x$val1, x$val2, x$val3, x$val4), by = list(x$id1, x$id2), mean)

What is the purpose of .PHONY in a Makefile?

The special target .PHONY: allows to declare phony targets, so that make will not check them as actual file names: it will work all the time even if such files still exist.

You can put several .PHONY: in your Makefile :

.PHONY: all

all : prog1 prog2

...

.PHONY: clean distclean

clean :
    ...
distclean :
    ...

There is another way to declare phony targets : simply put :: without prerequisites :

all :: prog1 prog2

...

clean ::
    ...
distclean ::
    ...

The :: has other special meanings, see here, but without prerequisites it always execute the recipes, even if the target already exists, thus acting as a phony target.

invalid use of non-static member function

You must make Foo::comparator static or wrap it in a std::mem_fun class object. This is because lower_bounds() expects the comparer to be a class of object that has a call operator, like a function pointer or a functor object. Also, if you are using C++11 or later, you can also do as dwcanillas suggests and use a lambda function. C++11 also has std::bind too.

Examples:

// Binding:
std::lower_bounds(first, last, value, std::bind(&Foo::comparitor, this, _1, _2));
// Lambda:
std::lower_bounds(first, last, value, [](const Bar & first, const Bar & second) { return ...; });

Circle-Rectangle collision detection (intersection)

This is the fastest solution:

public static boolean intersect(Rectangle r, Circle c)
{
    float cx = Math.abs(c.x - r.x - r.halfWidth);
    float xDist = r.halfWidth + c.radius;
    if (cx > xDist)
        return false;
    float cy = Math.abs(c.y - r.y - r.halfHeight);
    float yDist = r.halfHeight + c.radius;
    if (cy > yDist)
        return false;
    if (cx <= r.halfWidth || cy <= r.halfHeight)
        return true;
    float xCornerDist = cx - r.halfWidth;
    float yCornerDist = cy - r.halfHeight;
    float xCornerDistSq = xCornerDist * xCornerDist;
    float yCornerDistSq = yCornerDist * yCornerDist;
    float maxCornerDistSq = c.radius * c.radius;
    return xCornerDistSq + yCornerDistSq <= maxCornerDistSq;
}

Note the order of execution, and half the width/height is pre-computed. Also the squaring is done "manually" to save some clock cycles.

How can I get the sha1 hash of a string in node.js?

You can use:

  const sha1 = require('sha1');
  const crypt = sha1('Text');
  console.log(crypt);

For install:

  sudo npm install -g sha1
  npm install sha1 --save

rbenv not changing ruby version

Check that PATH contains $HOME/.rbenv/shims and $HOME/.rbenv/bin

$ env | grep PATH

Also check that you have the following in your ~/.bash_profile if using bash or ~/.zshenv if using zsh

export PATH="$HOME/.rbenv/bin:$PATH"
eval "$(rbenv init -)"

NOTE: Make sure it's the last setting in your ~/.bash_profile . I ran into an issue where I installed a program that updated my .bash_profile and reset PATH.

Finally, make sure your $HOME folder doesn't have a .ruby-version file that you may have created by accident if you were to have done $ rbenv local <ruby-version> in your $HOME folder. Doing $ rbenv global <ruby-version> modifies the $HOME/.rbenv/version file, and the existence of a .ruby-version file in the $HOME folder would override the version set by $HOME/.rbenv/version.

From the docs:

Choosing the Ruby Version When you execute a shim, rbenv determines which Ruby version to use by reading it from the following sources, in this order:

The RBENV_VERSION environment variable, if specified. You can use the rbenv shell command to set this environment variable in your current shell session.

The first .ruby-version file found by searching the directory of the script you are executing and each of its parent directories until reaching the root of your filesystem.

The first .ruby-version file found by searching the current working directory and each of its parent directories until reaching the root of your filesystem. You can modify the .ruby-version file in the current working directory with the rbenv local command.

The global ~/.rbenv/version file. You can modify this file using the rbenv global command. If the global version file is not present, rbenv assumes you want to use the "system" Ruby—i.e. whatever version would be run if rbenv weren't in your path.

jQuery: more than one handler for same event

jquery will execute both handler since it allows multiple event handlers. I have created sample code. You can try it

demo

How to get GET (query string) variables in Express.js on Node.js?

You can use with express ^4.15.4:

var express = require('express'),
    router = express.Router();
router.get('/', function (req, res, next) {
    console.log(req.query);
});

Hope this helps.

What is the right way to debug in iPython notebook?

The %pdb magic command is good to use as well. Just say %pdb on and subsequently the pdb debugger will run on all exceptions, no matter how deep in the call stack. Very handy.

If you have a particular line that you want to debug, just raise an exception there (often you already are!) or use the %debug magic command that other folks have been suggesting.

Oracle database: How to read a BLOB?

If you're interested to get the plaintext (body part) from a BLOB, you could use the CTX_DOC package.

For example, the CTX_DOC.FILTER procedure can "generate either a plain text or a HTML version of a document". Be aware that CTX_DOC.FILTER requires an index on the BLOB column. If you don't want that, you could use the CTX_DOC.POLICY_FILTER procedure instead, which doesn't require an index.

How can I get useful error messages in PHP?

The two key lines you need to get useful errors out of PHP are:

ini_set('display_errors',1);
 error_reporting(E_ALL);

As pointed out by other contributors, these are switched off by default for security reasons. As a useful tip - when you're setting up your site it's handy to do a switch for your different environments so that these errors are ON by default in your local and development environments. This can be achieved with the following code (ideally in your index.php or config file so this is active from the start):

switch($_SERVER['SERVER_NAME'])
{
    // local
    case 'yourdomain.dev':
    // dev
    case 'dev.yourdomain.com':
        ini_set('display_errors',1);
        error_reporting(E_ALL);
    break;
    //live
    case 'yourdomain.com':
        //...
    break;
}

Git Stash vs Shelve in IntelliJ IDEA

git shelve doesn't exist in Git.

Only git stash:

  • when you want to record the current state of the working directory and the index, but want to go back to a clean working directory.
  • which saves your local modifications away and reverts the working directory to match the HEAD commit.

You had a 2008 old project git shelve to isolate modifications in a branch, but that wouldn't be very useful nowadays.

As documented in Intellij IDEA shelve dialog, the feature "shelving and unshelving" is not linked to a VCS (Version Control System tool) but to the IDE itself, to temporarily storing pending changes you have not committed yet in changelist.

Note that since Git 2.13 (Q2 2017), you now can stash individual files too.

How to add spacing between UITableViewCell

I solved it like this way in Swift 4.

I create a extension of UITableViewCell and include this code:

override open var frame: CGRect {
    get {
        return super.frame
    }
    set (newFrame) {
        var frame =  newFrame
        frame.origin.y += 10
        frame.origin.x += 10
        frame.size.height -= 15
        frame.size.width -= 2 * 10
        super.frame = frame
    }
}

override open func awakeFromNib() {
    super.awakeFromNib()
    layer.cornerRadius = 15
    layer.masksToBounds = false
}

I hope it helps you.

How to change the name of an iOS app?

A note on the bundle display name -- this is the right way to change the name in your app menu, but you'll likely have to reset content and settings in your iOS simulator before you see the change actually take effect.

Can't pickle <type 'instancemethod'> when using multiprocessing Pool.map()

There's another short-cut you can use, although it can be inefficient depending on what's in your class instances.

As everyone has said the problem is that the multiprocessing code has to pickle the things that it sends to the sub-processes it has started, and the pickler doesn't do instance-methods.

However, instead of sending the instance-method, you can send the actual class instance, plus the name of the function to call, to an ordinary function that then uses getattr to call the instance-method, thus creating the bound method in the Pool subprocess. This is similar to defining a __call__ method except that you can call more than one member function.

Stealing @EricH.'s code from his answer and annotating it a bit (I retyped it hence all the name changes and such, for some reason this seemed easier than cut-and-paste :-) ) for illustration of all the magic:

import multiprocessing
import os

def call_it(instance, name, args=(), kwargs=None):
    "indirect caller for instance methods and multiprocessing"
    if kwargs is None:
        kwargs = {}
    return getattr(instance, name)(*args, **kwargs)

class Klass(object):
    def __init__(self, nobj, workers=multiprocessing.cpu_count()):
        print "Constructor (in pid=%d)..." % os.getpid()
        self.count = 1
        pool = multiprocessing.Pool(processes = workers)
        async_results = [pool.apply_async(call_it,
            args = (self, 'process_obj', (i,))) for i in range(nobj)]
        pool.close()
        map(multiprocessing.pool.ApplyResult.wait, async_results)
        lst_results = [r.get() for r in async_results]
        print lst_results

    def __del__(self):
        self.count -= 1
        print "... Destructor (in pid=%d) count=%d" % (os.getpid(), self.count)

    def process_obj(self, index):
        print "object %d" % index
        return "results"

Klass(nobj=8, workers=3)

The output shows that, indeed, the constructor is called once (in the original pid) and the destructor is called 9 times (once for each copy made = 2 or 3 times per pool-worker-process as needed, plus once in the original process). This is often OK, as in this case, since the default pickler makes a copy of the entire instance and (semi-) secretly re-populates it—in this case, doing:

obj = object.__new__(Klass)
obj.__dict__.update({'count':1})

—that's why even though the destructor is called eight times in the three worker processes, it counts down from 1 to 0 each time—but of course you can still get into trouble this way. If necessary, you can provide your own __setstate__:

    def __setstate__(self, adict):
        self.count = adict['count']

in this case for instance.

How do you add an action to a button programmatically in xcode

Swift answer:

myButton.addTarget(self, action: "click:", for: .touchUpInside)

func click(sender: UIButton) {
    print("click")
}

Documentation: https://developer.apple.com/documentation/uikit/uicontrol/1618259-addtarget

Java Error opening registry key

I had the same:

Error opening registry key 'Software\JavaSoft\Java Runtime Environment

Clearing Windows\SysWOW64 doesn't help for Win7

In my case it installing JDK8 offline helped (from link)

"No resource identifier found for attribute 'showAsAction' in package 'android'"

all above fix may not work in android studio .if you are using ANDROID STUDIO...... use this fix

add

xmlns:compat="http://schemas.android.com/tools"

in menu tag instead of

xmlns:compat="http://schemas.android.com/apk/res-auto"

in menu tag.

REST / SOAP endpoints for a WCF service

This is what i did to make it work. Make sure you put
webHttp automaticFormatSelectionEnabled="true" inside endpoint behaviour.

[ServiceContract]
public interface ITestService
{

    [WebGet(BodyStyle = WebMessageBodyStyle.Bare, UriTemplate = "/product", ResponseFormat = WebMessageFormat.Json)]
    string GetData();
}

public class TestService : ITestService
{
    public string GetJsonData()
    {
        return "I am good...";
    }
}

Inside service model

   <service name="TechCity.Business.TestService">

    <endpoint address="soap" binding="basicHttpBinding" name="SoapTest"
      bindingName="BasicSoap" contract="TechCity.Interfaces.ITestService" />
    <endpoint address="mex"
              contract="IMetadataExchange" binding="mexHttpBinding"/>
    <endpoint behaviorConfiguration="jsonBehavior" binding="webHttpBinding"
              name="Http" contract="TechCity.Interfaces.ITestService" />
    <host>
      <baseAddresses>
        <add baseAddress="http://localhost:8739/test" />
      </baseAddresses>
    </host>
  </service>

EndPoint Behaviour

  <endpointBehaviors>
    <behavior name="jsonBehavior">
      <webHttp automaticFormatSelectionEnabled="true"  />
      <!-- use JSON serialization -->
    </behavior>
  </endpointBehaviors>

What should be the package name of android app?

Package name is the reversed domain name, it is a unique name for each application on Playstore. You can't upload two apps with the same package name. You can check package name of the app from playstore url

https://play.google.com/store/apps/details?id=package_name

so you can easily check on playstore that this package name is in used by some other app or not before uploading it.

Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array

Here is a very light and easy way:

var codes = dc_1.split(',');
var i = codes.length;
while (i--) {
  if (codes.indexOf(codes[i]) != i) {
    codes.splice(i,1);
  }
}

Regarding Java switch statements - using return and omitting breaks in each case

Though the question is old enough it still can be referenced nowdays.

Semantically that is exactly what Java 12 introduced (https://openjdk.java.net/jeps/325), thus, exactly in that simple example provided I can't see any problem or cons.

Last Run Date on a Stored Procedure in SQL Server

I use this:

use YourDB;

SELECT 
    object_name(object_id), 
    last_execution_time, 
    last_elapsed_time, 
    execution_count
FROM   
     sys.dm_exec_procedure_stats ps 
where 
      lower(object_name(object_id)) like 'Appl-Name%'
order by 1

How to use onResume()?

Restarting the app will call OnCreate().

Continuing the app when it is paused will call OnResume(). From the official docs at https://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle here's a diagram of the activity lifecycle.

the Android activity lifecycle, from https://developer.android.com/images/activity_lifecycle.png on https://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle

$watch'ing for data changes in an Angular directive

You need to enable deep object dirty checking. By default angular only checks the reference of the top level variable that you watch.

App.directive('d3Visualization', function() {
    return {
        restrict: 'E',
        scope: {
            val: '='
        },
        link: function(scope, element, attrs) {
            scope.$watch('val', function(newValue, oldValue) {
                if (newValue)
                    console.log("I see a data change!");
            }, true);
        }
    }
});

see Scope. The third parameter of the $watch function enables deep dirty checking if it's set to true.

Take note that deep dirty checking is expensive. So if you just need to watch the children array instead of the whole data variable the watch the variable directly.

scope.$watch('val.children', function(newValue, oldValue) {}, true);

version 1.2.x introduced $watchCollection

Shallow watches the properties of an object and fires whenever any of the properties change (for arrays, this implies watching the array items; for object maps, this implies watching the properties)

scope.$watchCollection('val.children', function(newValue, oldValue) {});

How to fire a change event on a HTMLSelectElement if the new value is the same as the old?

Try this. Just add an empty option. This will solve your problem.

<select onchange="jsFunction()">
    <option></option>
    <option value="1">1</option>
    <option value="2">2</option>
    <option value="3">3</option>
</select>?

Chrome Uncaught Syntax Error: Unexpected Token ILLEGAL

There's some sort of bogus character at the end of that source. Try deleting the last line and adding it back.

I can't figure out exactly what's there, yet ...

edit — I think it's a zero-width space, Unicode 200B. Seems pretty weird and I can't be sure of course that it's not a Stackoverflow artifact, but when I copy/paste that last function including the complete last line into the Chrome console, I get your error.

A notorious source of such characters are websites like jsfiddle. I'm not saying that there's anything wrong with them — it's just a side-effect of something, maybe the use of content-editable input widgets.

If you suspect you've got a case of this ailment, and you're on MacOS or Linux/Unix, the od command line tool can show you (albeit in a fairly ugly way) the numeric values in the characters of the source code file. Some IDEs and editors can show "funny" characters as well. Note that such characters aren't always a problem. It's perfectly OK (in most reasonable programming languages, anyway) for there to be embedded Unicode characters in string constants, for example. The problems start happening when the language parser encounters the characters when it doesn't expect them.

Is "&#160;" a replacement of "&nbsp;"?

  • &nbsp; is the character entity reference (meant to be easily parseable by humans).
  • &#160; is the numeric entity reference (meant to be easily parseable by machines).

They are the same except for the fact that the latter does not need another lookup table to find its actual value. The lookup table is called a DTD, by the way.

You can read more about character entity references in the offical W3C documents.

How do I convert a date/time to epoch time (unix time/seconds since 1970) in Perl?

My favorite datetime parser is DateTime::Format::ISO8601 Once you've got that working, you'll have a DateTime object, easily convertable to epoch seconds with epoch()

Ignoring SSL certificate in Apache HttpClient 4.3

Slight tweak to answer from @divbyzero above to fix sonar security warnings

CloseableHttpClient getInsecureHttpClient() throws GeneralSecurityException {
            TrustStrategy trustStrategy = (chain, authType) -> true;

            HostnameVerifier hostnameVerifier = (hostname, session) -> hostname.equalsIgnoreCase(session.getPeerHost());

            return HttpClients.custom()
                    .setSSLSocketFactory(new SSLConnectionSocketFactory(new SSLContextBuilder().loadTrustMaterial(trustStrategy).build(), hostnameVerifier))
                    .build();
        }

javascript jquery radio button click

There are several ways to do this. Having a container around the radio buttons is highly recommended regardless, but you can also put a class directly on the buttons. With this HTML:

<ul id="shapeList" class="radioList">
<li><label>Shape:</label></li>
<li><input id="shapeList_0" class="shapeButton" type="radio" value="Circular" name="shapeList" /><label for="shapeList_0">Circular</label></li>
<li><input id="shapeList_1" class="shapeButton" type="radio" value="Rectangular" name="shapeList" /><label for="shapeList_1">Rectangular</label></li>
</ul>

you can select by class:

$(".shapeButton").click(SetShape);

or select by container ID:

$("#shapeList").click(SetShape);

In either case, the event will trigger on clicking either the radio button or the label for it, though oddly in the latter case (Selecting by "#shapeList"), clicking on the label will trigger the click function twice for some reason, at least in FireFox; selecting by class won't do that.

SetShape is a function, and looks like this:

function SetShape() {
    var Shape = $('.shapeButton:checked').val();
//dostuff
}

This way, you can have labels on your buttons, and can have multiple radio button lists on the same page that do different things. You can even have each individual button in the same list do different things by setting up different behavior in SetShape() based on the button's value.

MS Access: how to compact current database in VBA

If you don't wish to use compact on close (eg, because the front-end mdb is a robot program that runs continually), and you don't want to create a separate mdb just for compacting, consider using a cmd file.

I let my robot.mdb check its own size:

FileLen(CurrentDb.Name))

If its size exceeds 1 GB, it creates a cmd file like this ...

Dim f As Integer
Dim Folder As String
Dim Access As String
    'select Access in the correct PF directory (my robot.mdb runs in 32-bit MSAccess, on 32-bit and 64-bit machines)
    If Dir("C:\Program Files (x86)\Microsoft Office\Office\MSACCESS.EXE") > "" Then
        Access = """C:\Program Files (x86)\Microsoft Office\Office\MSACCESS.EXE"""
    Else
        Access = """C:\Program Files\Microsoft Office\Office\MSACCESS.EXE"""
    End If
    Folder = ExtractFileDir(CurrentDb.Name)
    f = FreeFile
    Open Folder & "comrep.cmd" For Output As f
    'wait until robot.mdb closes (ldb file is gone), then compact robot.mdb
    Print #f, ":checkldb1"
    Print #f, "if exist " & Folder & "robot.ldb goto checkldb1"
    Print #f, Access & " " & Folder & "robot.mdb /compact"
    'wait until the robot mdb closes, then start it
    Print #f, ":checkldb2"
    Print #f, "if exist " & Folder & "robot.ldb goto checkldb2"
    Print #f, Access & " " & Folder & "robot.mdb"
    Close f

... launches the cmd file ...

Shell ExtractFileDir(CurrentDb.Name) & "comrep.cmd"

... and shuts down ...

DoCmd.Quit

Next, the cmd file compacts and restarts robot.mdb.

Convert Java Array to Iterable

First of all, I can only agree that Arrays.asList(T...) is clearly the best solution for Wrapper types or arrays with non-primtive datatypes. This method calls a constructor of a simple private static AbstractList implementation in the Arrays class which basically saves the given array reference as field and simulates a list by overriding the needed methods.

If you can choose between a primtive type or a Wrapper type for your array, I would use the Wrapper type for such situations but of course, it's not always useful or required. There would be only two possibilities you can do:

1) You can create a class with a static method for each primitive datatype array (boolean, byte, short, int, long, char, float, double returning an Iterable<WrapperType>. These methods would use anonymous classes of Iterator (besides Iterable) which are allowed to contain the reference of the comprising method's argument (for example an int[]) as field in order to implement the methods.

-> This approach is performant and saves you memory (except for the memory of the newly created methods, even though, using Arrays.asList() would take memory in the same way)

2) Since arrays don't have methods (as to be read on the side you linked) they can't provide an Iterator instance either. If you really are too lazy to write new classes, you must use an instance of an already existing class that implements Iterable because there is no other way around than instantiating Iterable or a subtype.
The ONLY way to create an existing Collection derivative implementing Iterable is to use a loop (except you use anonymous classes as described above) or you instantiate an Iterable implementing class whose constructor allows a primtive type array (because Object[] doesn't allow arrays with primitive type elements) but as far as I know, the Java API doesn't feature a class like that.

The reason for the loop can be explained easily:
for each Collection you need Objects and primtive datatypes aren't objects. Objects are much bigger than primitive types so that they require additional data which must be generated for each element of the primitive type array. That means if two ways of three (using Arrays.asList(T...) or using an existing Collection) require an aggregate of objects, you need to create for each primitive value of your int[] array the wrapper object. The third way would use the array as is and use it in an anonymous class as I think it's preferable due to fast performance.

There is also a third strategy using an Object as argument for the method where you want to use the array or Iterable and it would require type checks to figure out which type the argument has, however I wouldn't recommend it at all as you usually need to consider that the Object hasn't always the required type and that you need seperate code for certain cases.

In conclusion, it's the fault of Java's problematic Generic Type system which doesn't allow to use primitive types as generic type which would save a lot of code by using simply Arrays.asList(T...). So you need to program for each primitive type array, you need, such a method (which basically makes no difference to the memory used by a C++ program which would create for each used type argument a seperate method.

PHP Undefined Index

I don't see php file, but that could be that -
replace in your php file:

$query_age = $_GET['query_age'];

with:

$query_age = (isset($_GET['query_age']) ? $_GET['query_age'] : null);

Most probably, at first time you running your script without ?query_age=[something] and $_GET has no key like query_age.

How to check if an element is visible with WebDriver

Here is how I would do it (please ignore worry Logger class calls):

public boolean isElementExist(By by) {
    int count = driver.findElements(by).size();
    if (count>=1) {
        Logger.LogMessage("isElementExist: " + by + " | Count: " + count, Priority.Medium);
        return true;
    }
    else {
        Logger.LogMessage("isElementExist: " + by + " | Could not find element", Priority.High);
        return false;
    }   
}

public boolean isElementNotExist(By by) {
    int count = driver.findElements(by).size();
    if (count==0) {
        Logger.LogMessage("ElementDoesNotExist: " + by, Priority.Medium);
        return true;
    }
    else {
        Logger.LogMessage("ElementDoesExist: " + by, Priority.High);
        return false;
    }   
}

public boolean isElementVisible(By by) {
    try {
        if (driver.findElement(by).isDisplayed()) {
            Logger.LogMessage("Element is Displayed: " + by, Priority.Medium);
            return true;
        }
    }
    catch(Exception e) {       
        Logger.LogMessage("Element is Not Displayed: " + by, Priority.High);
        return false;
    }       

    return false;
}

Tree view of a directory/folder in Windows?

In the Windows command prompt you can use "tree /F" to view a tree of the current folder and all descending files & folders.

In File Explorer under Windows 8.1:

  • Select folder
  • Press Shift, right-click mouse, and select "Open command window here"
  • Type tree /f > tree.txt and press Enter
  • Use MS Word to open "tree.txt"
  • The dialog box "File Conversion - tree.txt" will open
  • For "Text encoding" tick the "MS-DOS" option

You now have an editable tree structure file.

This works for versions of Windows from Windows XP to Windows 8.1.

JOptionPane Input to int

Simply use:

int ans = Integer.parseInt( JOptionPane.showInputDialog(frame,
        "Text",
        JOptionPane.INFORMATION_MESSAGE,
        null,
        null,
        "[sample text to help input]"));

You cannot cast a String to an int, but you can convert it using Integer.parseInt(string).

Dump all tables in CSV format using 'mysqldump'

It looks like others had this problem also, and there is a simple Python script now, for converting output of mysqldump into CSV files.

wget https://raw.githubusercontent.com/jamesmishra/mysqldump-to-csv/master/mysqldump_to_csv.py
mysqldump -u username -p --host=rdshostname database table | python mysqldump_to_csv.py > table.csv

'react-scripts' is not recognized as an internal or external command

To rectify this issue follow the following steps

  1. run npm install
  2. then run npm start

This worked fine for me

HttpGet with HTTPS : SSLPeerUnverifiedException

Method returning a "secureClient" (in a Java 7 environnement - NetBeans IDE and GlassFish Server: port https by default 3920 ), hope this could help :

public DefaultHttpClient secureClient() {
    DefaultHttpClient httpclient = new DefaultHttpClient();
    SSLSocketFactory sf;

    KeyStore trustStore;
    FileInputStream trustStream = null;
    File truststoreFile;
    // java.security.cert.PKIXParameters for the trustStore
    PKIXParameters pkixParamsTrust;

    KeyStore keyStore;
    FileInputStream keyStream = null;
    File keystoreFile;
    // java.security.cert.PKIXParameters for the keyStore
    PKIXParameters pkixParamsKey;

    try {
        trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
        truststoreFile = new File(TRUSTSTORE_FILE);
        keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
        keystoreFile = new File(KEYSTORE_FILE);
        try {
            trustStream = new FileInputStream(truststoreFile);
            keyStream = new FileInputStream(keystoreFile);
        } catch (FileNotFoundException ex) {
            Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
        }
        try {
            trustStore.load(trustStream, PASSWORD.toCharArray());
            keyStore.load(keyStream, PASSWORD.toCharArray());
        } catch (IOException ex) {
            Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
        } catch (CertificateException ex) {
            Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
        }
        try {
            pkixParamsTrust = new PKIXParameters(trustStore);
            // accepts Server certificate generated with keytool and (auto) signed by SUN
            pkixParamsTrust.setPolicyQualifiersRejected(false);
        } catch (InvalidAlgorithmParameterException ex) {
            Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
        }
        try {
            pkixParamsKey = new PKIXParameters(keyStore);
            // accepts Client certificate generated with keytool and (auto) signed by SUN
            pkixParamsKey.setPolicyQualifiersRejected(false);
        } catch (InvalidAlgorithmParameterException ex) {
            Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
        }
        try {
            sf = new SSLSocketFactory(trustStore);
            ClientConnectionManager manager = httpclient.getConnectionManager();
            manager.getSchemeRegistry().register(new Scheme("https", 3920, sf));
        } catch (KeyManagementException ex) {
            Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
        } catch (UnrecoverableKeyException ex) {
            Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
        }

    } catch (NoSuchAlgorithmException ex) {
        Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
    } catch (KeyStoreException ex) {
        Logger.getLogger(ApacheHttpRestClient.class.getName()).log(Level.SEVERE, null, ex);
    }
    // use the httpclient for any httpRequest
    return httpclient;
}