#Copilot | Programs & Examples on Copilot

How to get UTC timestamp in Ruby?

if you need a human-readable timestamp (like rails migration has) ex. "20190527141340"

Time.now.utc.to_formatted_s(:number)  # using Rails

Time.now.utc.strftime("%Y%m%d%H%M%S") # using Ruby

How do I clear the content of a div using JavaScript?

Just Javascript (as requested)

Add this function somewhere on your page (preferably in the <head>)

function clearBox(elementID)
{
    document.getElementById(elementID).innerHTML = "";
}

Then add the button on click event:

<button onclick="clearBox('cart_item')" />

In JQuery (for reference)

If you prefer JQuery you could do:

$("#cart_item").html("");

'AND' vs '&&' as operator

Here's a little counter example:

$a = true;
$b = true;
$c = $a & $b;
var_dump(true === $c);

output:

bool(false)

I'd say this kind of typo is far more likely to cause insidious problems (in much the same way as = vs ==) and is far less likely to be noticed than adn/ro typos which will flag as syntax errors. I also find and/or is much easier to read. FWIW, most PHP frameworks that express a preference (most don't) specify and/or. I've also never run into a real, non-contrived case where it would have mattered.

Pandas Replace NaN with blank/empty string

Use a formatter, if you only want to format it so that it renders nicely when printed. Just use the df.to_string(... formatters to define custom string-formatting, without needlessly modifying your DataFrame or wasting memory:

df = pd.DataFrame({
    'A': ['a', 'b', 'c'],
    'B': [np.nan, 1, np.nan],
    'C': ['read', 'unread', 'read']})
print df.to_string(
    formatters={'B': lambda x: '' if pd.isnull(x) else '{:.0f}'.format(x)})

To get:

   A B       C
0  a      read
1  b 1  unread
2  c      read

Get the client's IP address in socket.io

This works for the 2.3.0 version:

io.on('connection', socket => {
   const ip = socket.handshake.headers['x-forwarded-for'] || socket.conn.remoteAddress.split(":")[3];
   console.log(ip);
});

How do I use spaces in the Command Prompt?

Just add Quotation Mark

Example:"C:\Users\User Name"

Hope it got Solved!

Writing your own square root function

It's a common interview question asked by Facebook etc. I don't think it's a good idea to use the Newton's method in an interview. What if the interviewer ask you the mechanism of the Newton's method when you don't really understand it?

I provided a binary search based solution in Java which I believe everyone can understand.

public int sqrt(int x) {

    if(x < 0) return -1;
    if(x == 0 || x == 1) return x;

    int lowerbound = 1;
    int upperbound = x;
    int root = lowerbound + (upperbound - lowerbound)/2;

    while(root > x/root || root+1 <= x/(root+1)){
        if(root > x/root){
            upperbound = root;
        } else {
            lowerbound = root;
        }
        root = lowerbound + (upperbound - lowerbound)/2;
    }
    return root;
}

You can test my code here: leetcode: sqrt(x)

How to get AM/PM from a datetime in PHP

PHP Code:

date_default_timezone_set('Asia/Kolkata');
$currentDateTime=date('m/d/Y H:i:s');
$newDateTime = date('h:i A', strtotime($currentDateTime));
echo $newDateTime;

Output: 05:03 PM

Generate your own Error code in swift 3

 let error = NSError(domain:"", code:401, userInfo:[ NSLocalizedDescriptionKey: "Invaild UserName or Password"]) as Error
            self.showLoginError(error)

create an NSError object and typecast it to Error ,show it anywhere

private func showLoginError(_ error: Error?) {
    if let errorObj = error {
        UIAlertController.alert("Login Error", message: errorObj.localizedDescription).action("OK").presentOn(self)
    }
}

How to concatenate characters in java?

System.out.println(char1+""+char2+char3)

String s = char1+""+char2+char3;

Quick and easy file dialog in Python?

How to copy java.util.list Collection

You may create a new list with an input of a previous list like so:

List one = new ArrayList()
//... add data, sort, etc
List two = new ArrayList(one);

This will allow you to modify the order or what elemtents are contained independent of the first list.

Keep in mind that the two lists will contain the same objects though, so if you modify an object in List two, the same object will be modified in list one.

example:

MyObject value1 = one.get(0);
MyObject value2 = two.get(0);
value1 == value2 //true
value1.setName("hello");
value2.getName(); //returns "hello"

Edit

To avoid this you need a deep copy of each element in the list like so:

List<Torero> one = new ArrayList<Torero>();
//add elements

List<Torero> two = new Arraylist<Torero>();
for(Torero t : one){
    Torero copy = deepCopy(t);
    two.add(copy);
}

with copy like the following:

public Torero deepCopy(Torero input){
    Torero copy = new Torero();
    copy.setValue(input.getValue());//.. copy primitives, deep copy objects again

    return copy;
}

Where is web.xml in Eclipse Dynamic Web Project

If your deployment descriptor tab is disabled, then click on update libraries it will also do your work. It will create. Xml file in Web content

Faster alternative in Oracle to SELECT COUNT(*) FROM sometable

If you want just a rough estimate, you can extrapolate from a sample:

SELECT COUNT(*) * 100 FROM sometable SAMPLE (1);

For greater speed (but lower accuracy) you can reduce the sample size:

SELECT COUNT(*) * 1000 FROM sometable SAMPLE (0.1);

For even greater speed (but even worse accuracy) you can use block-wise sampling:

SELECT COUNT(*) * 100 FROM sometable SAMPLE BLOCK (1);

How to determine if one array contains all elements of another array

a = [5, 1, 6, 14, 2, 8]
b = [2, 6, 15]

a - b
# => [5, 1, 14, 8]

b - a
# => [15]

(b - a).empty?
# => false

What is the difference between class and instance methods?

Like the other answers have said, instance methods operate on an object and has access to its instance variables, while a class method operates on a class as a whole and has no access to a particular instance's variables (unless you pass the instance in as a parameter).

A good example of an class method is a counter-type method, which returns the total number of instances of a class. Class methods start with a +, while instance ones start with an -. For example:

static int numberOfPeople = 0;

@interface MNPerson : NSObject {
     int age;  //instance variable
}

+ (int)population; //class method. Returns how many people have been made.
- (id)init; //instance. Constructs object, increments numberOfPeople by one.
- (int)age; //instance. returns the person age
@end

@implementation MNPerson
- (id)init{
    if (self = [super init]){
          numberOfPeople++;
          age = 0;
    }    
    return self;
}

+ (int)population{ 
     return numberOfPeople;
}

- (int)age{
     return age;
}

@end

main.m:

MNPerson *micmoo = [[MNPerson alloc] init];
MNPerson *jon = [[MNPerson alloc] init];
NSLog(@"Age: %d",[micmoo age]);
NSLog(@"%Number Of people: %d",[MNPerson population]);

Output: Age: 0 Number Of people: 2

Another example is if you have a method that you want the user to be able to call, sometimes its good to make that a class method. For example, if you have a class called MathFunctions, you can do this:

+ (int)square:(int)num{ 
      return num * num;
}

So then the user would call:

[MathFunctions square:34];

without ever having to instantiate the class!

You can also use class functions for returning autoreleased objects, like NSArray's

+ (NSArray *)arrayWithObject:(id)object

That takes an object, puts it in an array, and returns an autoreleased version of the array that doesn't have to be memory managed, great for temperorary arrays and what not.

I hope you now understand when and/or why you should use class methods!!

How do I disable right click on my web page?

Disabling right click on your web page is simple. There are just a few lines of JavaScript code that will do this job. Below is the JavaScript code:

$("html").on("contextmenu",function(e){
   return false;
});

In the above code, I have selected the tag. After you add just that three lines of code, it will disable right click on your web page.

Source: Disable right click, copy, cut on web page using jQuery

Python 2,3 Convert Integer to "bytes" Cleanly

You can use the struct's pack:

In [11]: struct.pack(">I", 1)
Out[11]: '\x00\x00\x00\x01'

The ">" is the byte-order (big-endian) and the "I" is the format character. So you can be specific if you want to do something else:

In [12]: struct.pack("<H", 1)
Out[12]: '\x01\x00'

In [13]: struct.pack("B", 1)
Out[13]: '\x01'

This works the same on both python 2 and python 3.

Note: the inverse operation (bytes to int) can be done with unpack.

What exactly is RESTful programming?

If I had to reduce the original dissertation on REST to just 3 short sentences, I think the following captures its essence:

Resources are requested via URLs.
Protocols are limited to what you can communicate by using URLs.
Metadata is passed as name-value pairs (post data and query string parameters).

After that, it's easy to fall into debates about adaptations, coding conventions, and best practices.

Interestingly, there is no mention of HTTP POST, GET, DELETE, or PUT operations in the dissertation. That must be someone's later interpretation of a "best practice" for a "uniform interface".

When it comes to web services, it seems that we need some way of distinguishing WSDL and SOAP based architectures which add considerable overhead and arguably much unnecessary complexity to the interface. They also require additional frameworks and developer tools in order to implement. I'm not sure if REST is the best term to distinguish between common-sense interfaces and overly engineered interfaces such as WSDL and SOAP. But we need something.

printf not printing on console

Apparently this is a known bug of Eclipse. This bug is resolved with the resolution of WONT-FIX. I have no idea why though. here is the link: Eclipse C Console Bug.

isset PHP isset($_GET['something']) ? $_GET['something'] : ''

In PHP 7 you can write it even shorter:

$age = $_GET['age'] ?? 27;

This means that the $age variable will be set to the age parameter if it is provided in the URL, or it will default to 27.

See all new features of PHP 7.

How do I pass JavaScript variables to PHP?

Just save it in a cookie:

$(document).ready(function () {
  createCookie("height", $(window).height(), "10");
});

function createCookie(name, value, days) {
  var expires;
  if (days) {
    var date = new Date();
    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
    expires = "; expires=" + date.toGMTString();
  }
  else {
    expires = "";
  }
  document.cookie = escape(name) + "=" + escape(value) + expires + "; path=/";
}

And then read it with PHP:

<?PHP
   $_COOKIE["height"];
?>

It's not a pretty solution, but it works.

Add days to JavaScript Date

Some implementations to extend Date https://gist.github.com/netstart/c92e09730f3675ba8fb33be48520a86d

/**
 * just import, like
 *
 * import './../shared/utils/date.prototype.extendions.ts';
 */
declare global {
  interface Date {
    addDays(days: number, useThis?: boolean): Date;

    addSeconds(seconds: number): Date;

    addMinutes(minutes: number): Date;

    addHours(hours: number): Date;

    addMonths(months: number): Date;

    isToday(): boolean;

    clone(): Date;

    isAnotherMonth(date: Date): boolean;

    isWeekend(): boolean;

    isSameDate(date: Date): boolean;

    getStringDate(): string;
  }
}

Date.prototype.addDays = function(days: number): Date {
  if (!days) {
    return this;
  }
  this.setDate(this.getDate() + days);
  return this;
};

Date.prototype.addSeconds = function(seconds: number) {
  let value = this.valueOf();
  value += 1000 * seconds;
  return new Date(value);
};

Date.prototype.addMinutes = function(minutes: number) {
  let value = this.valueOf();
  value += 60000 * minutes;
  return new Date(value);
};

Date.prototype.addHours = function(hours: number) {
  let value = this.valueOf();
  value += 3600000 * hours;
  return new Date(value);
};

Date.prototype.addMonths = function(months: number) {
  const value = new Date(this.valueOf());

  let mo = this.getMonth();
  let yr = this.getYear();

  mo = (mo + months) % 12;
  if (0 > mo) {
    yr += (this.getMonth() + months - mo - 12) / 12;
    mo += 12;
  } else {
    yr += ((this.getMonth() + months - mo) / 12);
  }

  value.setMonth(mo);
  value.setFullYear(yr);
  return value;
};

Date.prototype.isToday = function(): boolean {
  const today = new Date();
  return this.isSameDate(today);
};

Date.prototype.clone = function(): Date {
  return new Date(+this);
};

Date.prototype.isAnotherMonth = function(date: Date): boolean {
  return date && this.getMonth() !== date.getMonth();
};

Date.prototype.isWeekend = function(): boolean {
  return this.getDay() === 0 || this.getDay() === 6;
};

Date.prototype.isSameDate = function(date: Date): boolean {
  return date && this.getFullYear() === date.getFullYear() && this.getMonth() === date.getMonth() && this.getDate() === date.getDate();
};

Date.prototype.getStringDate = function(): string {
  // Month names in Brazilian Portuguese
  const monthNames = ['Janeiro', 'Fevereiro', 'Março', 'Abril', 'Maio', 'Junho', 'Julho', 'Agosto', 'Setembro', 'Outubro', 'Novembro', 'Dezembro'];
  // Month names in English
  // let monthNames = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
  const today = new Date();
  if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay()) {
    return 'Hoje';
    // return "Today";
  } else if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay() + 1) {
    return 'Amanhã';
    // return "Tomorrow";
  } else if (this.getMonth() === today.getMonth() && this.getDay() === today.getDay() - 1) {
    return 'Ontem';
    // return "Yesterday";
  } else {
    return this.getDay() + ' de ' + this.monthNames[this.getMonth()] + ' de ' + this.getFullYear();
    // return this.monthNames[this.getMonth()] + ' ' + this.getDay() + ', ' +  this.getFullYear();
  }
};


export {};

ASP.Net Download file to client browser

Just a slight addition to the above solution if you are having problem with downloaded file's name...

Response.AddHeader("Content-Disposition", "attachment; filename=\"" + file.Name + "\"");

This will return the exact file name even if it contains spaces or other characters.

Detect end of ScrollView

I wanted to show/hide a FAB with an offset before the very bottom of the scrollview. This is the solution I came up with (Kotlin):

scrollview.viewTreeObserver.addOnScrollChangedListener {
    if (scrollview.scrollY < scrollview.getChildAt(0).bottom - scrollview.height - offset) {
        // fab.hide()
    } else {
        // fab.show()
    }
}

Difference between numeric, float and decimal in SQL Server

Although the question didn't include the MONEY data type some people coming across this thread might be tempted to use the MONEY data type for financial calculations.

Be wary of the MONEY data type, it's of limited precision.

There is a lot of good information about it in the answers to this Stackoverflow question:

Should you choose the MONEY or DECIMAL(x,y) datatypes in SQL Server?

Why does Java's hashCode() in String use 31 as a multiplier?

On (mostly) old processors, multiplying by 31 can be relatively cheap. On an ARM, for instance, it is only one instruction:

RSB       r1, r0, r0, ASL #5    ; r1 := - r0 + (r0<<5)

Most other processors would require a separate shift and subtract instruction. However, if your multiplier is slow this is still a win. Modern processors tend to have fast multipliers so it doesn't make much difference, so long as 32 goes on the correct side.

It's not a great hash algorithm, but it's good enough and better than the 1.0 code (and very much better than the 1.0 spec!).

JSON array get length

The below snippet works fine for me(I used the size())

String itemId;
            for (int i = 0; i < itemList.size(); i++) {
            JSONObject itemObj = (JSONObject)itemList.get(i);
            itemId=(String) itemObj.get("ItemId");
            System.out.println(itemId);
            }

If it is wrong to use use size() kindly advise

How do I Set Background image in Flutter?

I'm not sure I understand your question, but if you want the image to fill the entire screen you can use a DecorationImage with a fit of BoxFit.cover.

class BaseLayout extends StatelessWidget{
  @override
  Widget build(BuildContext context){
    return Scaffold(
      body: Container(
        decoration: BoxDecoration(
          image: DecorationImage(
            image: AssetImage("assets/images/bulb.jpg"),
            fit: BoxFit.cover,
          ),
        ),
        child: null /* add child content here */,
      ),
    );
  }
}

For your second question, here is a link to the documentation on how to embed resolution-dependent asset images into your app.

Can't create handler inside thread that has not called Looper.prepare() inside AsyncTask for ProgressDialog

final Handler handler = new Handler() {
        @Override
        public void handleMessage(final Message msgs) {
        //write your code hear which give error
        }
        }

new Thread(new Runnable() {
    @Override
    public void run() {
    handler.sendEmptyMessage(1);
        //this will call handleMessage function and hendal all error
    }
    }).start();

How to get status code from webclient?

Erik's answer doesn't work on Windows Phone as is. The following does:

class WebClientEx : WebClient
{
    private WebResponse m_Resp = null;

    protected override WebResponse GetWebResponse(WebRequest Req, IAsyncResult ar)
    {
        try
        {
            this.m_Resp = base.GetWebResponse(request);
        }
        catch (WebException ex)
        {
            if (this.m_Resp == null)
                this.m_Resp = ex.Response;
        }
        return this.m_Resp;
    }

    public HttpStatusCode StatusCode
    {
        get
        {
            if (m_Resp != null && m_Resp is HttpWebResponse)
                return (m_Resp as HttpWebResponse).StatusCode;
            else
                return HttpStatusCode.OK;
        }
    }
}

At least it does when using OpenReadAsync; for other xxxAsync methods, careful testing would be highly recommended. The framework calls GetWebResponse somewhere along the code path; all one needs to do is capture and cache the response object.

The fallback code is 200 in this snippet because genuine HTTP errors - 500, 404, etc - are reported as exceptions anyway. The purpose of this trick is to capture non-error codes, in my specific case 304 (Not modified). So the fallback assumes that if the status code is somehow unavailable, at least it's a non-erroneous one.

angular.element vs document.getElementById or jQuery selector with spin (busy) control

Maybe I am too late here but this will work :

var target = angular.element(appBusyIndicator);

Notice, there is no appBusyIndicator, it is plain ID value.

What is happening behind the scenes: (assuming it's applied on a div) (taken from angular.js line no : 2769 onwards...)

/////////////////////////////////////////////
function JQLite(element) {     //element = div#appBusyIndicator
  if (element instanceof JQLite) {
    return element;
  }

  var argIsString;

  if (isString(element)) {
    element = trim(element);
    argIsString = true;
  }
  if (!(this instanceof JQLite)) {
    if (argIsString && element.charAt(0) != '<') {
      throw jqLiteMinErr('nosel', 'Looking up elements via selectors is not supported by jqLite! See: http://docs.angularjs.org/api/angular.element');
    }
    return new JQLite(element);
  }

By default if there is no jQuery on the page, jqLite will be used. The argument is internally understood as an id and corresponding jQuery object is returned.

Getting "Skipping JaCoCo execution due to missing execution data file" upon executing JaCoCo

It happens if the path of your project has blank spaces somewhere, such as:

/home/user/my projects/awesome project

the report is not generated. If that is the case, remove those spaces from directory names.

About the plugin configuration, I just needed the basic as below:

<plugin>
    <groupId>org.jacoco</groupId>
    <artifactId>jacoco-maven-plugin</artifactId>
    <version>0.8.5</version>
    <executions>
        <execution>
            <id>jacoco-initialize</id>
            <goals>
                <goal>prepare-agent</goal>
            </goals>
        </execution>
        <execution>
            <id>jacoco-report</id>
            <goals>
                <goal>report</goal>
            </goals>
        </execution>
    </executions>       
</plugin>

How to schedule a function to run every hour on Flask?

You could try using APScheduler's BackgroundScheduler to integrate interval job into your Flask app. Below is the example that uses blueprint and app factory (init.py) :

from datetime import datetime

# import BackgroundScheduler
from apscheduler.schedulers.background import BackgroundScheduler
from flask import Flask

from webapp.models.main import db 
from webapp.controllers.main import main_blueprint    

# define the job
def hello_job():
    print('Hello Job! The time is: %s' % datetime.now())

def create_app(object_name):
    app = Flask(__name__)
    app.config.from_object(object_name)
    db.init_app(app)
    app.register_blueprint(main_blueprint)
    # init BackgroundScheduler job
    scheduler = BackgroundScheduler()
    # in your case you could change seconds to hours
    scheduler.add_job(hello_job, trigger='interval', seconds=3)
    scheduler.start()

    try:
        # To keep the main thread alive
        return app
    except:
        # shutdown if app occurs except 
        scheduler.shutdown()

Hope it helps :)

Ref :

https://github.com/agronholm/apscheduler/blob/master/examples/schedulers/background.py

VB.NET: how to prevent user input in a ComboBox

Private Sub ComboBox4_KeyPress(sender As Object, e As KeyPressEventArgs) Handles ComboBox4.KeyPress
    e.keyChar = string.empty
End Sub

Simple search MySQL database using php

First add HTML code:

<form action="" method="post">
<input type="text" name="search">
<input type="submit" name="submit" value="Search">
</form>

Now added PHP code:

<?php
$search_value=$_POST["search"];
$con=new mysqli($servername,$username,$password,$dbname);
if($con->connect_error){
    echo 'Connection Faild: '.$con->connect_error;
    }else{
        $sql="select * from information where First_Name like '%$search_value%'";

        $res=$con->query($sql);

        while($row=$res->fetch_assoc()){
            echo 'First_name:  '.$row["First_Name"];


            }       

        }
?>

How to use the new Material Design Icon themes: Outlined, Rounded, Two-Tone and Sharp?

I was unsatisfied that until know Google hasn't yet released their new designs as font or svg icon set. Therefore I put together a small npm package to solve the problem.

https://www.npmjs.com/package/ts-material-icons-svg

Simply import the icons you wanna use and add them to your registry. This also supports tree shaking since only those icons are added to your project that you really want and/or need.

npm i --save https://github.com/MarcusCalidus/ts-material-icons-svg.git

to use two tone icons for example

import {icon_edit} from 'ts-material-icons-svg/dist/twotone';

matIconRegistry.addSvgIcon(
            'edit',
            domSanitizer.bypassSecurityTrustResourceUrl(icon_edit),
        );

In your html template you now can use the new icon

<mat-icon svgIcon="edit"></mat-icon>

Include PHP file into HTML file

You would have to configure your webserver to utilize PHP as handler for .html files. This is typically done by modifying your with AddHandler to include .html along with .php.

Note that this could have a performance impact as this would cause ALL .html files to be run through PHP handler even if there is no PHP involved. So you might strongly consider using .php extension on these files and adding a redirect as necessary to route requests to specific .html URL's to their .php equivalents.

Get integer value of the current year in Java

This simplest (using Calendar, sorry) is:

 int year = Calendar.getInstance().get(Calendar.YEAR);

There is also the new Date and Time API JSR, as well as Joda Time

Start a fragment via Intent within a Fragment

Try this it may help you:

public void ButtonClick(View view) {
    Fragment mFragment = new YourNextFragment(); 
    getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, mFragment).commit();
}

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

Does "pure HTML/CSS" exclude the use of tables? Because they will easily do what you want:

<table>
    <tr>
        <td valign="top"><img src="myImage.jpg" alt="" /></td>
        <td valign="middle">This is my text!</td>
    </tr>
</table>

Flame me all you like, but that works (and works in old, janky browsers).

TypeError: module.init() takes at most 2 arguments (3 given)

Even after @Mickey Perlstein's answer and his 3 hours of detective work, it still took me a few more minutes to apply this to my own mess. In case anyone else is like me and needs a little more help, here's what was going on in my situation.

responses is a module
Response is a base class within the responses module
GeoJsonResponse is a new class derived from Response

Initial GeoJsonResponse class:

from pyexample.responses import Response

class GeoJsonResponse(Response):

    def __init__(self, geo_json_data):

Looks fine. No problems until you try to debug the thing, which is when you get a bunch of seemingly vague error messages like this:

from pyexample.responses import GeoJsonResponse ..\pyexample\responses\GeoJsonResponse.py:12: in (module) class GeoJsonResponse(Response):

E TypeError: module() takes at most 2 arguments (3 given)

=================================== ERRORS ====================================

___________________ ERROR collecting tests/test_geojson.py ____________________

test_geojson.py:2: in (module) from pyexample.responses import GeoJsonResponse ..\pyexample\responses \GeoJsonResponse.py:12: in (module)

class GeoJsonResponse(Response): E TypeError: module() takes at most 2 arguments (3 given)

ERROR: not found: \PyExample\tests\test_geojson.py::TestGeoJson::test_api_response

C:\Python37\lib\site-packages\aenum__init__.py:163

(no name 'PyExample\ tests\test_geojson.py::TestGeoJson::test_api_response' in any of [])

The errors were doing their best to point me in the right direction, and @Mickey Perlstein's answer was dead on, it just took me a minute to put it all together in my own context:

I was importing the module:

from pyexample.responses import Response

when I should have been importing the class:

from pyexample.responses.Response import Response

Hope this helps someone. (In my defense, it's still pretty early.)

Suppress output of a function

Making Hadley's comment to an answer (hope to make it better visible). Use of apply family without printing is possible with use of the plyr package

x <- 1:2
lapply(x, function(x) x + 1)
#> [[1]]
#> [1] 2
#> 
#> [[2]]
#> [1] 3

plyr::l_ply(x, function(x) x + 1)

^{Created on 2020-05-19 by the reprex package (v0.3.0)}

C - function inside struct

This will only work in C++. Functions in structs are not a feature of C.

Same goes for your client.AddClient(); call ... this is a call for a member function, which is object oriented programming, i.e. C++.

Convert your source to a .cpp file and make sure you are compiling accordingly.

If you need to stick to C, the code below is (sort of) the equivalent:

typedef struct client_t client_t, *pno;
struct client_t
{
        pid_t pid;
        char password[TAM_MAX]; // -> 50 chars
        pno next;

};


pno AddClient(pno *pclient) 
{
    /* code */
}


int main()
{

    client_t client;

    //code ..

    AddClient(client);

}

Python os.path.join on Windows

The reason os.path.join('C:', 'src') is not working as you expect is because of something in the documentation that you linked to:

Note that on Windows, since there is a current directory for each drive, os.path.join("c:", "foo") represents a path relative to the current directory on drive C: (c:foo), not c:\foo.

As ghostdog said, you probably want mypath=os.path.join('c:\\', 'sourcedir')

Google API for location, based on user IP address

Google already appends location data to all requests coming into GAE (see Request Header documentation for go, java, php and python). You should be interested X-AppEngine-Country, X-AppEngine-Region, X-AppEngine-City and X-AppEngine-CityLatLong headers.

An example looks like this:

X-AppEngine-Country:US
X-AppEngine-Region:ca
X-AppEngine-City:norwalk
X-AppEngine-CityLatLong:33.902237,-118.081733

Responsive web design is working on desktop but not on mobile device

Responsive meta tag

To ensure proper rendering and touch zooming for all devices, add the responsive viewport meta tag to your <head>.

<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">

Pretty-Print JSON Data to a File using Python

If you are generating new *.json or modifying existing josn file the use "indent" parameter for pretty view json format.

import json
responseData = json.loads(output)
with open('twitterData.json','w') as twitterDataFile:    
    json.dump(responseData, twitterDataFile, indent=4)

Android - Launcher Icon Size

I had the same problem but then realized the arrangement of my icon graphic within the square allowed (512 x 512 in my case) was not maximized. So I rotated the image and was able to scale it up to fill the corners better. Then I right clicked on my res folder in my project in Android Studio, then choose New then Image Asset, it took me through a wizard where I got to select my image file to use. Then if you check the box that says "Trim surrounding blank space", it makes sure all edges, that are able, touch the sides of your square. These steps got it much bigger than the original.

Removing multiple keys from a dictionary safely

If you also need to retrieve the values for the keys you are removing, this would be a pretty good way to do it:

values_removed = [d.pop(k, None) for k in entities_to_remove]

You could of course still do this just for the removal of the keys from d, but you would be unnecessarily creating the list of values with the list comprehension. It is also a little unclear to use a list comprehension just for the function's side effect.

Please add a @Pipe/@Directive/@Component annotation. Error

I faced the same error when I used another class instead of component down the component decorator.

Component class must come just after the component decorator

  @Component({
 selector: 'app-smsgtrecon',
 templateUrl: './smsgtrecon.component.html',
 styleUrls: ['./smsgtrecon.component.css'],
 providers: [ChecklistDatabase]
 })


// THIS CAUSE ISSUE MOVE THIS UP TO COMPONENT DECORATOR
/**
* Node for to-do item
*/
 export class TodoItemNode {
 children: TodoItemNode[];
 item: string;
}


 export class SmsgtreconComponent implements OnInit {

After moving TodoItemNode to the top of component decorator it worked

Solution

// THIS CAUSE ISSUE MOVE THIS UP TO COMPONENT DECORATOR
/**
* Node for to-do item
*/
 export class TodoItemNode {
 children: TodoItemNode[];
 item: string;
}


@Component({
 selector: 'app-smsgtrecon',
 templateUrl: './smsgtrecon.component.html',
 styleUrls: ['./smsgtrecon.component.css'],
 providers: [ChecklistDatabase]
 })


 export class SmsgtreconComponent implements OnInit {

Getting ssh to execute a command in the background on target machine

Quickest and easiest way is to use the 'at' command:

ssh user@target "at now -f /home/foo.sh"

When use ResponseEntity<T> and @RestController for Spring RESTful applications

A proper REST API should have below components in response

Status Code
Response Body
Location to the resource which was altered(for example, if a resource was created, client would be interested to know the url of that location)

The main purpose of ResponseEntity was to provide the option 3, rest options could be achieved without ResponseEntity.

So if you want to provide the location of resource then using ResponseEntity would be better else it can be avoided.

Consider an example where a API is modified to provide all the options mentioned

// Step 1 - Without any options provided
@RequestMapping(value="/{id}", method=RequestMethod.GET)
public @ResponseBody Spittle spittleById(@PathVariable long id) {
  return spittleRepository.findOne(id);
}

// Step 2- We need to handle exception scenarios, as step 1 only caters happy path.
@ExceptionHandler(SpittleNotFoundException.class)
@ResponseStatus(HttpStatus.NOT_FOUND)
public Error spittleNotFound(SpittleNotFoundException e) {
  long spittleId = e.getSpittleId();
  return new Error(4, "Spittle [" + spittleId + "] not found");
}

// Step 3 - Now we will alter the service method, **if you want to provide location**
@RequestMapping(
    method=RequestMethod.POST
    consumes="application/json")
public ResponseEntity<Spittle> saveSpittle(
    @RequestBody Spittle spittle,
    UriComponentsBuilder ucb) {

  Spittle spittle = spittleRepository.save(spittle);
  HttpHeaders headers = new HttpHeaders();
  URI locationUri =
  ucb.path("/spittles/")
      .path(String.valueOf(spittle.getId()))
      .build()
      .toUri();
  headers.setLocation(locationUri);
  ResponseEntity<Spittle> responseEntity =
      new ResponseEntity<Spittle>(
          spittle, headers, HttpStatus.CREATED)
  return responseEntity;
}

// Step4 - If you are not interested to provide the url location, you can omit ResponseEntity and go with
@RequestMapping(
    method=RequestMethod.POST
    consumes="application/json")
@ResponseStatus(HttpStatus.CREATED)
public Spittle saveSpittle(@RequestBody Spittle spittle) {
  return spittleRepository.save(spittle);
}

How do you see recent SVN log entries?

limit option, e.g.:

svn log --limit 4

svn log -l 4

Only the last 4 entries

Owl Carousel Won't Autoplay

If you using v1.3.3 then use following property

autoPlay : 5000

Or using latest version then use following property

autoPlay : true

What is the maximum value for an int32?

It's 10 digits, so pretend it's a phone number (assuming you're in the US). 214-748-3647. I don't recommend calling it.

Copy folder recursively in Node.js

The fs-extra module works like a charm.

Install fs-extra:

$ npm install fs-extra

The following is the program to copy a source directory to a destination directory.

// Include the fs-extra package
var fs = require("fs-extra");

var source = 'folderA'
var destination = 'folderB'

// Copy the source folder to the destination
fs.copy(source, destination, function (err) {
    if (err){
        console.log('An error occurred while copying the folder.')
        return console.error(err)
    }
    console.log('Copy completed!')
});

References

fs-extra: https://www.npmjs.com/package/fs-extra

Example: Node.js Tutorial - Node.js Copy a Folder

How to copy directory recursively in python and overwrite all?

In Python 3.8 the dirs_exist_ok keyword argument was added to shutil.copytree():

dirs_exist_ok dictates whether to raise an exception in case dst or any missing parent directory already exists.

So, the following will work in recent versions of Python, even if the destination directory already exists:

shutil.copytree(src, dest, dirs_exist_ok=True)  # 3.8+ only!

One major benefit is that it's more flexible than distutils.dir_util.copy_tree() as it takes additional arguments on files to ignore, etc. There is also a draft PEP (PEP 632, associated discussion), which suggests that distutils may be deprecated and then removed in future versions of Python 3.

Find the number of employees in each department - SQL Oracle

Please try:

select count(*) as count,dept.DNAME 
from emp 
inner join dept on emp.DEPTNO = dept.DEPTNO 
group by dept.DNAME

Pretty Printing JSON with React

Here is a demo react_hooks_debug_print.html in react hooks that is based on Chris's answer. The json data example is from https://json.org/example.html.

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>Hello World</title>
    <script src="https://unpkg.com/react@16/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>

    <!-- Don't use this in production: -->
    <script src="https://unpkg.com/[email protected]/babel.min.js"></script>
  </head>
  <body>
    <div id="root"></div>
    <script src="https://raw.githubusercontent.com/cassiozen/React-autobind/master/src/autoBind.js"></script>

    <script type="text/babel">

let styles = {
  root: { backgroundColor: '#1f4662', color: '#fff', fontSize: '12px', },
  header: { backgroundColor: '#193549', padding: '5px 10px', fontFamily: 'monospace', color: '#ffc600', },
  pre: { display: 'block', padding: '10px 30px', margin: '0', overflow: 'scroll', }
}

let data = {
  "glossary": {
    "title": "example glossary",
    "GlossDiv": {
      "title": "S",
      "GlossList": {
        "GlossEntry": {
          "ID": "SGML",
          "SortAs": "SGML",
          "GlossTerm": "Standard Generalized Markup Language",
          "Acronym": "SGML",
          "Abbrev": "ISO 8879:1986",
          "GlossDef": {
            "para": "A meta-markup language, used to create markup languages such as DocBook.",
            "GlossSeeAlso": [
              "GML",
              "XML"
            ]
          },
          "GlossSee": "markup"
        }
      }
    }
  }
}

const DebugPrint = () => {
  const [show, setShow] = React.useState(false);

  return (
    <div key={1} style={styles.root}>
    <div style={styles.header} onClick={ ()=>{setShow(!show)} }>
        <strong>Debug</strong>
    </div>
    { show 
      ? (
      <pre style={styles.pre}>
       {JSON.stringify(data, null, 2) }
      </pre>
      )
      : null
    }
    </div>
  )
}

ReactDOM.render(
  <DebugPrint data={data} />, 
  document.getElementById('root')
);

    </script>

  </body>
</html>

Or in the following way, add the style into header:

    <style>
.root { background-color: #1f4662; color: #fff; fontSize: 12px; }
.header { background-color: #193549; padding: 5px 10px; fontFamily: monospace; color: #ffc600; }
.pre { display: block; padding: 10px 30px; margin: 0; overflow: scroll; }
    </style>

And replace DebugPrint with the follows:

const DebugPrint = () => {
  // https://stackoverflow.com/questions/30765163/pretty-printing-json-with-react
  const [show, setShow] = React.useState(false);

  return (
    <div key={1} className='root'>
    <div className='header' onClick={ ()=>{setShow(!show)} }>
        <strong>Debug</strong>
    </div>
    { show 
      ? (
      <pre className='pre'>
       {JSON.stringify(data, null, 2) }
      </pre>
      )
      : null
    }
    </div>
  )
}

LD_LIBRARY_PATH vs LIBRARY_PATH

LIBRARY_PATH is used by gcc before compilation to search directories containing static and shared libraries that need to be linked to your program.

LD_LIBRARY_PATH is used by your program to search directories containing shared libraries after it has been successfully compiled and linked.

EDIT: As pointed below, your libraries can be static or shared. If it is static then the code is copied over into your program and you don't need to search for the library after your program is compiled and linked. If your library is shared then it needs to be dynamically linked to your program and that's when LD_LIBRARY_PATH comes into play.

How to copy a string of std::string type in C++?

Caesar's solution is the best in my opinion, but if you still insist to use the strcpy function, then after you have your strings ready:

string a = "text";
string b = "image";

You can try either:

strcpy(a.data(), b.data());

strcpy(a.c_str(), b.c_str());

Just call either the data() or c_str() member functions of the std::string class, to get the char* pointer of the string object.

The strcpy() function doesn't have overload to accept two std::string objects as parameters. It has only one overload to accept two char* pointers as parameters.

Both data and c_str return what does strcpy() want exactly.

Write applications in C or C++ for Android?

Take a look at google ndk group it looks promising, first version of the NDK will be available in 1H2009.

Update: And it is released http://android-developers.blogspot.com/2009/06/introducing-android-15-ndk-release-1.html

Difference between break and continue statement

here's the semantic of break:

int[] a = new int[] { 1, 3, 4, 6, 7, 9, 10 };
// find 9
for(int i = 0; i < a.Length; i++)
{
    if (a[i] == 9) 
        goto goBreak;

    Console.WriteLine(a[i].ToString());      
}
goBreak:;

here's the semantic of continue:

int[] a = new int[] { 1, 3, 4, 6, 7, 9, 10 };
// skip all odds
for(int i = 0; i < a.Length; i++)
{
    if (a[i] % 2 == 1) 
        goto goContinue;

    Console.WriteLine(a[i].ToString());      

goContinue:;
}

Import a custom class in Java

First off, avoid using the default package.

Second of all, you don't need to import the class; it's in the same package.

Create controller for partial view in ASP.NET MVC

The most important thing is, the action created must return partial view, see below.

public ActionResult _YourPartialViewSection()
{
    return PartialView();
}

How can I change all input values to uppercase using Jquery?

use css :

input.upper { text-transform: uppercase; }

probably best to use the style, and convert serverside. There's also a jQuery plugin to force uppercase: http://plugins.jquery.com/plugin-tags/uppercase

How does Go update third-party packages?

go get will install the package in the first directory listed at GOPATH (an environment variable which might contain a colon separated list of directories). You can use go get -u to update existing packages.

You can also use go get -u all to update all packages in your GOPATH

For larger projects, it might be reasonable to create different GOPATHs for each project, so that updating a library in project A wont cause issues in project B.

Type go help gopath to find out more about the GOPATH environment variable.

C# Passing Function as Argument

public static T Runner<T>(Func<T> funcToRun)
{
    //Do stuff before running function as normal
    return funcToRun();
}

Usage:

var ReturnValue = Runner(() => GetUser(99));

'Linker command failed with exit code 1' when using Google Analytics via CocoaPods

Go to your build settings and switch the target's settings to ENABLE_BITCODE = YES for now.

How do I center align horizontal <UL> menu?

I used the display:inline-block property: the solution consist in use a wrapper with fixed width. Inside, the ul block with the inline-block for display. Using this, the ul just take the width for the real content! and finally margin: 0 auto, to center this inline-block =)

/*ul wrapper*/
.gallery_wrapper{
        width:          958px;
        margin:         0 auto;
  }
/*ul list*/
ul.gallery_carrousel{
        display:        inline-block;
        margin:         0 auto;
}
.contenido_secundario li{
        float:          left;
}

How do I add a resources folder to my Java project in Eclipse

Build Path -> Configure Build Path -> Libraries (Tab) -> Add Class Folder, then select your folder or create one.

Multiple github accounts on the same computer?

This answer is for beginners (none-git gurus). I recently had this problem and maybe its just me but most of the answers seemed to require rather advance understanding of git. After reading several stack overflow answers including this thread, here are the steps I needed to take in order to easily switch between GitHub accounts (e.g. assume two GitHub accounts, github.com/personal and gitHub.com/work):

Check for existing ssh keys: Open Terminal and run this command to see/list existing ssh keys ls -al ~/.ssh
files with extension .pub are your ssh keys so you should have two for the personal and work accounts. If there is only one or none, its time to generate other wise skip this.

- Generating ssh key: login to github (either the personal or work acc.), navigate to Settings and copy the associated email.
now go back to Terminal and run ssh-keygen -t rsa -C "the copied email", you'll see:

Generating public/private rsa key pair.
Enter file in which to save the key (/.../.ssh/id_rsa):

id_rsa is the default name for the soon to be generated ssh key so copy the path and rename the default, e.g. /.../.ssh/id_rsa_work if generating for work account. provide a password or just enter to ignore and, you'll read something like The key's randomart image is: and the image. done.
Repeat this step once more for your second github account. Make sure you use the right email address and a different ssh key name (e.g. id_rsa_personal) to avoid overwriting.
At this stage, you should see two ssh keys when running ls -al ~/.ssh again.
Associate ssh key with gitHub account: Next step is to copy one of the ssh keys, run this but replacing your own ssh key name: pbcopy < ~/.ssh/id_rsa_work.pub, replace id_rsa_work.pub with what you called yours.
Now that our ssh key is copied to clipboard, go back to github account [Make sure you're logged in to work account if the ssh key you copied is id_rsa_work] and navigate to
Settings - SSH and GPG Keys and click on New SSH key button (not New GPG key btw :D)
give some title for this key, paste the key and click on Add SSH key. You've now either successfully added the ssh key or noticed it has been there all along which is fine (or you got an error because you selected New GPG key instead of New SSH key :D).
Associate ssh key with gitHub account: Repeat the above step for your second account.
Edit the global git configuration: Last step is to make sure the global configuration file is aware of all github accounts (so to say).
Run git config --global --edit to edit this global file, if this opens vim and you don't know how to use it, press i to enter Insert mode, edit the file as below, and press esc followed by :wq to exit insert mode:

[inside this square brackets give a name to the followed acc.] name = github_username email = github_emailaddress [any other name] name = github_username email = github_email [credential] helper = osxkeychain useHttpPath = true

Done!, now when trying to push or pull from a repo, you'll be asked which GitHub account should be linked with this repo and its asked only once, the local configuration will remember this link and not the global configuration so you can work on different repos that are linked with different accounts without having to edit global configuration each time.

Convert Java Date to UTC String

Following the useful comments, I've completely rebuilt the date formatter. Usage is supposed to:

Be short (one liner)
Represent disposable objects (time zone, format) as Strings
Support useful, sortable ISO formats and the legacy format from the box

If you consider this code useful, I may publish the source and a JAR in github.

Usage

// The problem - not UTC
Date.toString()                      
"Tue Jul 03 14:54:24 IDT 2012"

// ISO format, now
PrettyDate.now()        
"2012-07-03T11:54:24.256 UTC"

// ISO format, specific date
PrettyDate.toString(new Date())         
"2012-07-03T11:54:24.256 UTC"

// Legacy format, specific date
PrettyDate.toLegacyString(new Date())   
"Tue Jul 03 11:54:24 UTC 2012"

// ISO, specific date and time zone
PrettyDate.toString(moonLandingDate, "yyyy-MM-dd hh:mm:ss zzz", "CST") 
"1969-07-20 03:17:40 CDT"

// Specific format and date
PrettyDate.toString(moonLandingDate, "yyyy-MM-dd")
"1969-07-20"

// ISO, specific date
PrettyDate.toString(moonLandingDate)
"1969-07-20T20:17:40.234 UTC"

// Legacy, specific date
PrettyDate.toLegacyString(moonLandingDate)
"Wed Jul 20 08:17:40 UTC 1969"

Code

(This code is also the subject of a question on Code Review stackexchange)

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

/**
 * Formats dates to sortable UTC strings in compliance with ISO-8601.
 * 
 * @author Adam Matan <[email protected]>
 * @see http://stackoverflow.com/questions/11294307/convert-java-date-to-utc-string/11294308
 */
public class PrettyDate {
    public static String ISO_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSS zzz";
    public static String LEGACY_FORMAT = "EEE MMM dd hh:mm:ss zzz yyyy";
    private static final TimeZone utc = TimeZone.getTimeZone("UTC");
    private static final SimpleDateFormat legacyFormatter = new SimpleDateFormat(LEGACY_FORMAT);
    private static final SimpleDateFormat isoFormatter = new SimpleDateFormat(ISO_FORMAT);
    static {
        legacyFormatter.setTimeZone(utc);
        isoFormatter.setTimeZone(utc);
    }

    /**
     * Formats the current time in a sortable ISO-8601 UTC format.
     * 
     * @return Current time in ISO-8601 format, e.g. :
     *         "2012-07-03T07:59:09.206 UTC"
     */
    public static String now() {
        return PrettyDate.toString(new Date());
    }

    /**
     * Formats a given date in a sortable ISO-8601 UTC format.
     * 
     * <pre>
     * <code>
     * final Calendar moonLandingCalendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
     * moonLandingCalendar.set(1969, 7, 20, 20, 18, 0);
     * final Date moonLandingDate = moonLandingCalendar.getTime();
     * System.out.println("UTCDate.toString moon:       " + PrettyDate.toString(moonLandingDate));
     * >>> UTCDate.toString moon:       1969-08-20T20:18:00.209 UTC
     * </code>
     * </pre>
     * 
     * @param date
     *            Valid Date object.
     * @return The given date in ISO-8601 format.
     * 
     */

    public static String toString(final Date date) {
        return isoFormatter.format(date);
    }

    /**
     * Formats a given date in the standard Java Date.toString(), using UTC
     * instead of locale time zone.
     * 
     * <pre>
     * <code>
     * System.out.println(UTCDate.toLegacyString(new Date()));
     * >>> "Tue Jul 03 07:33:57 UTC 2012"
     * </code>
     * </pre>
     * 
     * @param date
     *            Valid Date object.
     * @return The given date in Legacy Date.toString() format, e.g.
     *         "Tue Jul 03 09:34:17 IDT 2012"
     */
    public static String toLegacyString(final Date date) {
        return legacyFormatter.format(date);
    }

    /**
     * Formats a date in any given format at UTC.
     * 
     * <pre>
     * <code>
     * final Calendar moonLandingCalendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
     * moonLandingCalendar.set(1969, 7, 20, 20, 17, 40);
     * final Date moonLandingDate = moonLandingCalendar.getTime();
     * PrettyDate.toString(moonLandingDate, "yyyy-MM-dd")
     * >>> "1969-08-20"
     * </code>
     * </pre>
     * 
     * 
     * @param date
     *            Valid Date object.
     * @param format
     *            String representation of the format, e.g. "yyyy-MM-dd"
     * @return The given date formatted in the given format.
     */
    public static String toString(final Date date, final String format) {
        return toString(date, format, "UTC");
    }

    /**
     * Formats a date at any given format String, at any given Timezone String.
     * 
     * 
     * @param date
     *            Valid Date object
     * @param format
     *            String representation of the format, e.g. "yyyy-MM-dd HH:mm"
     * @param timezone
     *            String representation of the time zone, e.g. "CST"
     * @return The formatted date in the given time zone.
     */
    public static String toString(final Date date, final String format, final String timezone) {
        final TimeZone tz = TimeZone.getTimeZone(timezone);
        final SimpleDateFormat formatter = new SimpleDateFormat(format);
        formatter.setTimeZone(tz);
        return formatter.format(date);
    }
}

What is the 'dynamic' type in C# 4.0 used for?

An example of use :

You consume many classes that have a commun property 'CreationDate' :

public class Contact
{
    // some properties

    public DateTime CreationDate { get; set; }        
}

public class Company
{
    // some properties

    public DateTime CreationDate { get; set; }

}

public class Opportunity
{
    // some properties

    public DateTime CreationDate { get; set; }

}

If you write a commun method that retrieves the value of the 'CreationDate' Property, you'd have to use reflection:

    static DateTime RetrieveValueOfCreationDate(Object item)
    {
        return (DateTime)item.GetType().GetProperty("CreationDate").GetValue(item);
    }

With the 'dynamic' concept, your code is much more elegant :

    static DateTime RetrieveValueOfCreationDate(dynamic item)
    {
        return item.CreationDate;
    }

PostgreSQL column 'foo' does not exist

I fixed similar issues by qutating column name

SELECT * from table_name where "foo" is NULL;

In my case it was just

SELECT id, "foo" from table_name;

without quotes i'v got same error.

Environ Function code samples for VBA

Environ() gets you the value of any environment variable. These can be found by doing the following command in the Command Prompt:

set

If you wanted to get the username, you would do:

Environ("username")

If you wanted to get the fully qualified name, you would do:

Environ("userdomain") & "\" & Environ("username")

References

Microsoft | Office VBA Reference | Language Reference VBA | Environ Function
Microsoft | Office Support | Environ Function

ant warning: "'includeantruntime' was not set"

i faced this same, i check in in program and feature. there was an update has install for jdk1.8 which is not compatible with my old setting(jdk1.6.0) for ant in eclipse. I install that update. right now, my ant project is build success.

Try it, hope this will be helpful.

.h or .hpp for your class definitions

C++ ("C Plus Plus") makes sense as .cpp

Having header files with a .hpp extension doesn't have the same logical flow.

Using $state methods with $stateChangeStart toState and fromState in Angular ui-router

Suggestion 1

When you add an object to $stateProvider.state that object is then passed with the state. So you can add additional properties which you can read later on when needed.

Example route configuration

$stateProvider
.state('public', {
    abstract: true,
    module: 'public'
})
.state('public.login', {
    url: '/login',
    module: 'public'
})
.state('tool', {
    abstract: true,
    module: 'private'
})
.state('tool.suggestions', {
    url: '/suggestions',
    module: 'private'
});

The $stateChangeStart event gives you acces to the toState and fromState objects. These state objects will contain the configuration properties.

Example check for the custom module property

$rootScope.$on('$stateChangeStart', function(e, toState, toParams, fromState, fromParams) {
    if (toState.module === 'private' && !$cookies.Session) {
        // If logged out and transitioning to a logged in page:
        e.preventDefault();
        $state.go('public.login');
    } else if (toState.module === 'public' && $cookies.Session) {
        // If logged in and transitioning to a logged out page:
        e.preventDefault();
        $state.go('tool.suggestions');
    };
});

I didn't change the logic of the cookies because I think that is out of scope for your question.

Suggestion 2

You can create a Helper to get you this to work more modular.

Value publicStates

myApp.value('publicStates', function(){
    return {
      module: 'public',
      routes: [{
        name: 'login', 
        config: { 
          url: '/login'
        }
      }]
    };
});

Value privateStates

myApp.value('privateStates', function(){
    return {
      module: 'private',
      routes: [{
        name: 'suggestions', 
        config: { 
          url: '/suggestions'
        }
      }]
    };
});

The Helper

myApp.provider('stateshelperConfig', function () {
  this.config = {
    // These are the properties we need to set
    // $stateProvider: undefined
    process: function (stateConfigs){
      var module = stateConfigs.module;
      $stateProvider = this.$stateProvider;
      $stateProvider.state(module, {
        abstract: true,
        module: module
      });
      angular.forEach(stateConfigs, function (route){
        route.config.module = module;
        $stateProvider.state(module + route.name, route.config);
      });
    }
  };

  this.$get = function () {
    return {
      config: this.config
    };
  };
});

Now you can use the helper to add the state configuration to your state configuration.

myApp.config(['$stateProvider', '$urlRouterProvider', 
    'stateshelperConfigProvider', 'publicStates', 'privateStates',
  function ($stateProvider, $urlRouterProvider, helper, publicStates, privateStates) {
    helper.config.$stateProvider = $stateProvider;
    helper.process(publicStates);
    helper.process(privateStates);
}]);

This way you can abstract the repeated code, and come up with a more modular solution.

Note: the code above isn't tested

Validating file types by regular expression

You can embed case insensitity into the regular expression like so:

\.(?i:)(?:jpg|gif|doc|pdf)$

How to check if a service is running on Android?

I use the following from inside an activity:

private boolean isMyServiceRunning(Class<?> serviceClass) {
    ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
    for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
        if (serviceClass.getName().equals(service.service.getClassName())) {
            return true;
        }
    }
    return false;
}

And I call it using:

isMyServiceRunning(MyService.class)

This works reliably, because it is based on the information about running services provided by the Android operating system through ActivityManager#getRunningServices.

All the approaches using onDestroy or onSometing events or Binders or static variables will not work reliably because as a developer you never know, when Android decides to kill your process or which of the mentioned callbacks are called or not. Please note the "killable" column in the lifecycle events table in the Android documentation.

Exception in thread "main" java.lang.UnsupportedClassVersionError: a (Unsupported major.minor version 51.0)

Copy the contents of the PATH settings to a notepad and check if the location for the 1.4.2 comes before that of the 7. If so, remove the path to 1.4.2 in the PATH setting and save it.

After saving and applying "Environment Variables" close and reopen the cmd line. In XP the path does no get reflected in already running programs.

Update date + one year in mysql

For multiple interval types use a nested construction as in:

 UPDATE table SET date = DATE_ADD(DATE_ADD(date, INTERVAL 1 YEAR), INTERVAL 1 DAY)

For updating a given date in the column date to 1 year + 1 day

Awk if else issues

Try the code

awk '{s=($3==0)?"-":$3/$4; print s}'

JavaScript require() on client side

Simply use Browserify, what is something like a compiler that process your files before it go into production and packs the file in bundles.

Think you have a main.js file that require the files of your project, when you run browserify in it, it simply process all and creates a bundle with all your files, allowing the use of the require calls synchronously in the browser without HTTP requests and with very little overhead for the performance and for the size of the bundle, for example.

See the link for more info: http://browserify.org/

MVC Return Partial View as JSON

Instead of RenderViewToString I prefer a approach like

return Json(new { Url = Url.Action("Evil", model) });

then you can catch the result in your javascript and do something like

success: function(data) {
    $.post(data.Url, function(partial) { 
        $('#IdOfDivToUpdate').html(partial);
    });
}

Reading inputStream using BufferedReader.readLine() is too slow

I have a longer test to try. This takes an average of 160 ns to read each line as add it to a List (Which is likely to be what you intended as dropping the newlines is not very useful.

public static void main(String... args) throws IOException {
    final int runs = 5 * 1000 * 1000;

    final ServerSocket ss = new ServerSocket(0);
    new Thread(new Runnable() {
        @Override
        public void run() {
            try {
                Socket serverConn = ss.accept();
                String line = "Hello World!\n";
                BufferedWriter br = new BufferedWriter(new OutputStreamWriter(serverConn.getOutputStream()));
                for (int count = 0; count < runs; count++)
                    br.write(line);
                serverConn.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }).start();

    Socket conn = new Socket("localhost", ss.getLocalPort());

    long start = System.nanoTime();
    BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
    String line;

    List<String> responseData = new ArrayList<String>();
    while ((line = in.readLine()) != null) {
        responseData.add(line);
    }
    long time = System.nanoTime() - start;
    System.out.println("Average time to read a line was " + time / runs + " ns.");
    conn.close();
    ss.close();
}

prints

Average time to read a line was 158 ns.

If you want to build a StringBuilder, keeping newlines I would suggets the following approach.

Reader r = new InputStreamReader(conn.getInputStream());
String line;

StringBuilder sb = new StringBuilder();
char[] chars = new char[4*1024];
int len;
while((len = r.read(chars))>=0) {
    sb.append(chars, 0, len);
}

Still prints

Average time to read a line was 159 ns.

In both cases, the speed is limited by the sender not the receiver. By optimising the sender, I got this timing down to 105 ns per line.

Example of Named Pipes

You can actually write to a named pipe using its name, btw.

Open a command shell as Administrator to get around the default "Access is denied" error:

echo Hello > \\.\pipe\PipeName

Jersey client: How to add a list as query parameter

@GET does support List of Strings

Setup:
Java : 1.7
Jersey version : 1.9

Resource

@Path("/v1/test")

Subresource:

// receive List of Strings
@GET
@Path("/receiveListOfStrings")
public Response receiveListOfStrings(@QueryParam("list") final List<String> list){
    log.info("receieved list of size="+list.size());
    return Response.ok().build();
}

Jersey testcase

@Test
public void testReceiveListOfStrings() throws Exception {
    WebResource webResource = resource();
    ClientResponse responseMsg = webResource.path("/v1/test/receiveListOfStrings")
            .queryParam("list", "one")
            .queryParam("list", "two")
            .queryParam("list", "three")
            .get(ClientResponse.class);
    Assert.assertEquals(200, responseMsg.getStatus());
}

Batch - If, ElseIf, Else

@echo off

set "language=de"

IF "%language%" == "de" (
    goto languageDE
) ELSE (
    IF "%language%" == "en" (
        goto languageEN
    ) ELSE (
    echo Not found.
    )
)

:languageEN
:languageDE

echo %language%

This works , but not sure how your language variable is defined.Does it have spaces in its definition.

Should I always use a parallel stream when possible?

The Stream API was designed to make it easy to write computations in a way that was abstracted away from how they would be executed, making switching between sequential and parallel easy.

However, just because its easy, doesn't mean its always a good idea, and in fact, it is a bad idea to just drop .parallel() all over the place simply because you can.

First, note that parallelism offers no benefits other than the possibility of faster execution when more cores are available. A parallel execution will always involve more work than a sequential one, because in addition to solving the problem, it also has to perform dispatching and coordinating of sub-tasks. The hope is that you'll be able to get to the answer faster by breaking up the work across multiple processors; whether this actually happens depends on a lot of things, including the size of your data set, how much computation you are doing on each element, the nature of the computation (specifically, does the processing of one element interact with processing of others?), the number of processors available, and the number of other tasks competing for those processors.

Further, note that parallelism also often exposes nondeterminism in the computation that is often hidden by sequential implementations; sometimes this doesn't matter, or can be mitigated by constraining the operations involved (i.e., reduction operators must be stateless and associative.)

In reality, sometimes parallelism will speed up your computation, sometimes it will not, and sometimes it will even slow it down. It is best to develop first using sequential execution and then apply parallelism where

(A) you know that there's actually benefit to increased performance and

(B) that it will actually deliver increased performance.

(A) is a business problem, not a technical one. If you are a performance expert, you'll usually be able to look at the code and determine (B), but the smart path is to measure. (And, don't even bother until you're convinced of (A); if the code is fast enough, better to apply your brain cycles elsewhere.)

The simplest performance model for parallelism is the "NQ" model, where N is the number of elements, and Q is the computation per element. In general, you need the product NQ to exceed some threshold before you start getting a performance benefit. For a low-Q problem like "add up numbers from 1 to N", you will generally see a breakeven between N=1000 and N=10000. With higher-Q problems, you'll see breakevens at lower thresholds.

But the reality is quite complicated. So until you achieve experthood, first identify when sequential processing is actually costing you something, and then measure if parallelism will help.

Mailx send html message

I had successfully used the following on Arch Linux (where the -a flag is used for attachments) for several years:

mailx -s "The Subject $( echo -e "\nContent-Type: text/html" [email protected] < email.html

This appended the Content-Type header to the subject header, which worked great until a recent update. Now the new line is filtered out of the -s subject. Presumably, this was done to improve security.

Instead of relying on hacking the subject line, I now use a bash subshell:

(
    echo -e "Content-Type: text/html\n"
    cat mail.html
 ) | mail -s "The Subject" -t [email protected]

And since we are really only using mailx's subject flag, it seems there is no reason not to switch to sendmail as suggested by @dogbane:

(
    echo "To: [email protected]"
    echo "Subject: The Subject"
    echo "Content-Type: text/html"
    echo
    cat mail.html
) | sendmail -t

The use of bash subshells avoids having to create a temporary file.

Printf width specifier to maintain precision of floating-point value

I run a small experiment to verify that printing with DBL_DECIMAL_DIG does indeed exactly preserve the number's binary representation. It turned out that for the compilers and C libraries I tried, DBL_DECIMAL_DIG is indeed the number of digits required, and printing with even one digit less creates a significant problem.

#include <float.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

union {
    short s[4];
    double d;
} u;

void
test(int digits)
{
    int i, j;
    char buff[40];
    double d2;
    int n, num_equal, bin_equal;

    srand(17);
    n = num_equal = bin_equal = 0;
    for (i = 0; i < 1000000; i++) {
        for (j = 0; j < 4; j++)
            u.s[j] = (rand() << 8) ^ rand();
        if (isnan(u.d))
            continue;
        n++;
        sprintf(buff, "%.*g", digits, u.d);
        sscanf(buff, "%lg", &d2);
        if (u.d == d2)
            num_equal++;
        if (memcmp(&u.d, &d2, sizeof(double)) == 0)
            bin_equal++;
    }
    printf("Tested %d values with %d digits: %d found numericaly equal, %d found binary equal\n", n, digits, num_equal, bin_equal);
}

int
main()
{
    test(DBL_DECIMAL_DIG);
    test(DBL_DECIMAL_DIG - 1);
    return 0;
}

I run this with Microsoft's C compiler 19.00.24215.1 and gcc version 7.4.0 20170516 (Debian 6.3.0-18+deb9u1). Using one less decimal digit halves the number of numbers that compare exactly equal. (I also verified that rand() as used indeed produces about one million different numbers.) Here are the detailed results.

Microsoft C

Tested 999507 values with 17 digits: 999507 found numericaly equal, 999507 found binary equal
Tested 999507 values with 16 digits: 545389 found numericaly equal, 545389 found binary equal

GCC

Tested 999485 values with 17 digits: 999485 found numericaly equal, 999485 found binary equal
Tested 999485 values with 16 digits: 545402 found numericaly equal, 545402 found binary equal

anaconda update all possible packages?

To answer more precisely to the question:

conda (which is conda for miniconda as for Anaconda) updates all but ONLY within a specific version of a package -> major and minor. That's the paradigm.

In the documentation you will find "NOTE: Conda updates to the highest version in its series, so Python 2.7 updates to the highest available in the 2.x series and 3.6 updates to the highest available in the 3.x series." doc

If Wang does not gives a reproducible example, one can only assist. e.g. is it really the virtual environment he wants to update or could Wang get what he/she wants with

conda update -n ENVIRONMENT --all

*PLEASE read the docs before executing "update --all"! This does not lead to an update of all packages by nature. Because conda tries to resolve the relationship of dependencies between all packages in your environment, this can lead to DOWNGRADED packages without warnings.

If you only want to update almost all, you can create a pin file

echo "conda ==4.0.0" >> ~/miniconda3/envs/py35/conda-meta/pinned
echo "numpy 1.7.*" >> ~/miniconda3/envs/py35/conda-meta/pinned

before running the update. conda issues not pinned

If later on you want to ignore the file in your env for an update, you can do:

conda update --all --no-pin

You should not do update --all. If you need it nevertheless you are saver to test this in a cloned environment.

First step should always be to backup your current specification:

conda list -n py35 --explicit

(but even so there is not always a link to the source available - like for jupyterlab extensions)

Next you can clone and update:

conda create -n py356 --clone py35

conda activate py356
conda config --set pip_interop_enabled True # for conda>=4.6
conda update --all

conda config

update:

Because the idea of conda is nice but it is not working out very well for complex environments I personally prefer the combination of nix-shell (or lorri) and poetry [as superior pip/conda .-)] (intro poetry2nix).

Alternatively you can use nix and mach-nix (where you only need you requirements file. It resolves and builds environments best.

On Linux / macOS you could use nix like

nix-env -iA nixpkgs.python37

to enter an environment that has e.g. in this case Python3.7 (for sure you can change the version)

or as a very good Python (advanced) environment you can use mach-nix (with nix) like

mach-nix env ./env -r requirements.txt

(which even supports conda [but currently in beta])

or via api like

nix-shell -p nixFlakes --run "nix run github:davhau/mach-nix#with.ipython.pandas.seaborn.bokeh.scikit-learn "

Finally if you really need to work with packages that are not compatible due to its dependencies, it is possible with technologies like NixOS/nix-pkgs.

What is DOM Event delegation?

To understand event delegation first we need to know why and when we actually need or want event delegation.

There may be many cases but let's discuss two big use cases for event delegation. 1. The first case is when we have an element with lots of child elements that we are interested in. In this case, instead of adding an event handler to all of these child elements, we simply add it to the parent element and then determine on which child element the event was fired.

2.The second use case for event delegation is when we want an event handler attached to an element that is not yet in the DOM when our page is loaded. That's, of course, because we cannot add an event handler to something that's not on our page, so in a case of deprecation that we're coding.

Suppose you have a list of 0, 10, or 100 items in the DOM when you load your page, and more items are waiting in your hand to add in the list. So there is no way to attach an event handler for the future elements or those elements are not added in the DOM yet, and also there may be a lot of items, so it wouldn't be useful to have one event handler attached to each of them.

Event Delegation

All right, so in order to talk about event delegation, the first concept that we actually need to talk about is event bubbling.

Event bubbling: Event bubbling means that when an event is fired or triggered on some DOM element, for example by clicking on our button here on the bellow image, then the exact same event is also triggered on all of the parent elements.

The event is first fired on the button, but then it will also be fired on all the parent elements one at a time, so it will also fire on the paragraph to the section the main element and actually all the way up in a DOM tree until the HTML element which is the root. So we say that the event bubbles up inside the DOM tree, and that's why it's called bubbling.

Target element: The element on which the event was actually first fired called the target element, so the element that caused the event to happen, is called the target element. In our above example here it's, of course, the button that was clicked. The important part is that this target element is stored as a property in the event object, This means that all the parent elements on which the event will also fire will know the target element of the event, so where the event was first fired.

That brings us to event delegation because if the event bubbles up in the DOM tree, and if we know where the event was fired then we can simply attach an event handler to a parent element and wait for the event to bubble up, and we can then do whatever we intended to do with our target element. This technique is called event delegation. In this example here, we could simply add the event handler to the main element.

All right, so again, event delegation is to not set up the event handler on the original element that we're interested in but to attach it to a parent element and, basically, catch the event there because it bubbles up. We can then act on the element that we're interested in using the target element property.

Example: Now lets assume we have two list item in our page, after adding items in those list programmtically we want to delete one or more items from them. Using event delegation tecnique we can achive our ppurpose easily.

<div class="body">
    <div class="top">

    </div>
    <div class="bottom">
        <div class="other">
            <!-- other bottom elements -->
        </div>
        <div class="container clearfix">
            <div class="income">
                <h2 class="icome__title">Income</h2>
                <div class="income__list">
                    <!-- list items -->
                </div>
            </div>
            <div class="expenses">
                <h2 class="expenses__title">Expenses</h2>
                <div class="expenses__list">
                    <!-- list items -->
                </div>
            </div>
        </div>
    </div>
</div>

Adding items in those list:

const DOMstrings={
        type:{
            income:'inc',
            expense:'exp'
        },
        incomeContainer:'.income__list',
        expenseContainer:'.expenses__list',
        container:'.container'
   }


var addListItem = function(obj, type){
        //create html string with the place holder
        var html, element;
        if(type===DOMstrings.type.income){
            element = DOMstrings.incomeContainer
            html = `<div class="item clearfix" id="inc-${obj.id}">
            <div class="item__description">${obj.descripiton}</div>
            <div class="right clearfix">
                <div class="item__value">${obj.value}</div>
                <div class="item__delete">
                    <button class="item__delete--btn"><i class="ion-ios-close-outline"></i></button>
                </div>
            </div>
        </div>`
        }else if (type ===DOMstrings.type.expense){
            element=DOMstrings.expenseContainer;
            html = ` <div class="item clearfix" id="exp-${obj.id}">
            <div class="item__description">${obj.descripiton}</div>
            <div class="right clearfix">
                <div class="item__value">${obj.value}</div>
                <div class="item__percentage">21%</div>
                <div class="item__delete">
                    <button class="item__delete--btn"><i class="ion-ios-close-outline"></i></button>
                </div>
            </div>
        </div>`
        }
        var htmlObject = document.createElement('div');
        htmlObject.innerHTML=html;
        document.querySelector(element).insertAdjacentElement('beforeend', htmlObject);
    }

Delete items:

var ctrlDeleteItem = function(event){
       // var itemId = event.target.parentNode.parentNode.parentNode.parentNode.id;
        var parent = event.target.parentNode;
        var splitId, type, ID;
        while(parent.id===""){
            parent = parent.parentNode
        }
        if(parent.id){
            splitId = parent.id.split('-');
            type = splitId[0];
            ID=parseInt(splitId[1]);
        }

        deleteItem(type, ID);
        deleteListItem(parent.id);
 }

 var deleteItem = function(type, id){
        var ids, index;
        ids = data.allItems[type].map(function(current){
            return current.id;
        });
        index = ids.indexOf(id);
        if(index>-1){
            data.allItems[type].splice(index,1);
        }
    }

  var deleteListItem = function(selectorID){
        var element = document.getElementById(selectorID);
        element.parentNode.removeChild(element);
    }

How can I stop float left?

You could modify .adm and add

.adm{
 clear:both;
}

That should make it move to a new line

PHP cURL not working - WAMP on Windows 7 64 bit

I had the same exact issue. After trying almost everything and digging on Stack Overflow, I finally found the reason. Try downloading "fixed curl extension" separately from PHP 5.4.3 and PHP 5.3.13 x64 (64 bit) for Windows.

I've downloaded "php_curl-5.4.3-VC9-x64", and it worked for me. I hope it helps.

get UTC time in PHP

Obtaining UTC date

gmdate("Y-m-d H:i:s");

Obtaining UTC timestamp

time();

The result will not be different even you have date_default_timezone_set on your code.

How to register multiple implementations of the same interface in Asp.Net Core?

FooA, FooB and FooC implements IFoo

Services Provider:

services.AddTransient<FooA>(); // Note that there is no interface
services.AddTransient<FooB>();
services.AddTransient<FooC>();

services.AddSingleton<Func<Type, IFoo>>(x => type =>
{
    return (IFoo)x.GetService(type);
});

Destination:

public class Test
{
    private readonly IFoo foo;

    public Test(Func<Type, IFoo> fooFactory)
    {
        foo = fooFactory(typeof(FooA));
    }

    ....

}

If you want to change the FooA to FooAMock for test purposes:

services.AddTransient<FooAMock>();

services.AddSingleton<Func<Type, IFoo>>(x => type =>
{
    if(type.Equals(typeof(FooA))
        return (IFoo)x.GetService(typeof(FooAMock));
    return null;
});

ggplot2 line chart gives "geom_path: Each group consist of only one observation. Do you need to adjust the group aesthetic?"

I got a similar prompt. It was because I had specified the x-axis in terms of some percentage (for example: 10%A, 20%B,....). So an alternate approach could be that you multiply these values and write them in the simplest form.

VLook-Up Match first 3 characters of one column with another column

=IF(ISNUMBER(SEARCH(LEFT(H2,3),I2)),"YES","NO")))

for each inside a for each - Java

Your syntax is not correct. It should be like that:

for (Tweet tweet : tweets) {              
    for(long forId : idFromArray){
        long tweetId = tweet.getId();
        if(forId != tweetId){
            String twitterString = tweet.getText();
            db.insertTwitter(twitterString);
        }
    }
}

EDIT

This answer no longer really answers the question since it was updated ;)

Ways to save enums in database

If saving enums as strings in the database, you can create utility methods to (de)serialize any enum:

   public static String getSerializedForm(Enum<?> enumVal) {
        String name = enumVal.name();
        // possibly quote value?
        return name;
    }

    public static <E extends Enum<E>> E deserialize(Class<E> enumType, String dbVal) {
        // possibly handle unknown values, below throws IllegalArgEx
        return Enum.valueOf(enumType, dbVal.trim());
    }

    // Sample use:
    String dbVal = getSerializedForm(Suit.SPADE);
    // save dbVal to db in larger insert/update ...
    Suit suit = deserialize(Suit.class, dbVal);

How to get the Development/Staging/production Hosting Environment in ConfigureServices

This can be accomplished without any extra properties or method parameters, like so:

public void ConfigureServices(IServiceCollection services)
{
    IServiceProvider serviceProvider = services.BuildServiceProvider();
    IHostingEnvironment env = serviceProvider.GetService<IHostingEnvironment>();

    if (env.IsProduction()) DoSomethingDifferentHere();
}

How can I get enum possible values in a MySQL database?

For PHP 5.6+

$mysqli = new mysqli("example.com","username","password","database");
$result = $mysqli->query("SELECT COLUMN_TYPE FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME='table_name' AND COLUMN_NAME='column_name'");
$row = $result->fetch_assoc();
var_dump($row);

Resolve host name to an ip address

This is hard to answer without more detail about the network architecture. Some things to investigate are:

Is it possible that client and/or server is behind a NAT device, a firewall, or similar?
Is any of the IP addresses involved a "local" address, like 192.168.x.y or 10.x.y.z?
What are the host names, are they "real" DNS:able names or something more local and/or Windows-specific?
How does the client look up the server? There must be a place in code or config data that holds the host name, simply try using the IP there instead if you want to avoid the lookup.

Sum of Numbers C++

mystycs, you are using the variable i to control your loop, however you are editing the value of i within the loop:

for (int i=0; i < positiveInteger; i++)
{
    i = startingNumber + 1;
    cout << i;
}

Try this instead:

int sum = 0;

for (int i=0; i < positiveInteger; i++)
{
    sum = sum + i;
    cout << sum << " " << i;
}

Swift days between two NSDates

  func completeOffset(from date:Date) -> String? {

    let formatter = DateComponentsFormatter()
    formatter.unitsStyle = .brief

    return  formatter.string(from: Calendar.current.dateComponents([.year,.month,.day,.hour,.minute,.second], from: date, to: self))




}

if you need year month days and hours as string use this

var tomorrow = Calendar.current.date(byAdding: .day, value: 1, to: Date())!

let dc = tomorrow.completeOffset(from: Date())

How do you convert a byte array to a hexadecimal string in C?

This is one way of performing the conversion:

#include<stdio.h>
#include<stdlib.h>

#define l_word 15
#define u_word 240

char *hex_str[]={"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"};

main(int argc,char *argv[]) {


     char *str = malloc(50);
     char *tmp;
     char *tmp2;

     int i=0;


     while( i < (argc-1)) {
          tmp = hex_str[*(argv[i]) & l_word];
          tmp2 = hex_str[*(argv[i]) & u_word];

          if(i == 0) { memcpy(str,tmp2,1); strcat(str,tmp);}
          else { strcat(str,tmp2); strcat(str,tmp);}
          i++;
    }

    printf("\n*********  %s  *************** \n", str);

}

How to specify a multi-line shell variable?

I would like to give one additional answer, while the other ones will suffice in most cases.

I wanted to write a string over multiple lines, but its contents needed to be single-line.

sql="                       \
SELECT c1, c2               \
from Table1, ${TABLE2}      \
where ...                   \
"

I am sorry if this if a bit off-topic (I did not need this for SQL). However, this post comes up among the first results when searching for multi-line shell variables and an additional answer seemed appropriate.

Superscript in Python plots

Alternatively, in python 3.6+, you can generate Unicode superscript and copy paste that in your code:

ax1.set_ylabel('Rate (min?¹)')

Detect when input has a 'readonly' attribute

Try a simple way:

if($('input[readonly="readonly"]')){
   alert("foo");
}

Getting current directory in .NET web application

The current directory is a system-level feature; it returns the directory that the server was launched from. It has nothing to do with the website.

You want HttpRuntime.AppDomainAppPath.

If you're in an HTTP request, you can also call Server.MapPath("~/Whatever").

Javascript, Change google map marker color

You can use this code it works fine.

 var pinImage = new google.maps.MarkerImage("http://www.googlemapsmarkers.com/v1/009900/");

 var marker = new google.maps.Marker({
            position: yourlatlong,
            icon: pinImage,
            map: map
        });

see Example here

What does it mean if a Python object is "subscriptable" or not?

A scriptable object is an object that records the operations done to it and it can store them as a "script" which can be replayed.

For example, see: Application Scripting Framework

Now, if Alistair didn't know what he asked and really meant "subscriptable" objects (as edited by others), then (as mipadi also answered) this is the correct one:

A subscriptable object is any object that implements the __getitem__ special method (think lists, dictionaries).

How do I force Postgres to use a particular index?

Assuming you're asking about the common "index hinting" feature found in many databases, PostgreSQL doesn't provide such a feature. This was a conscious decision made by the PostgreSQL team. A good overview of why and what you can do instead can be found here. The reasons are basically that it's a performance hack that tends to cause more problems later down the line as your data changes, whereas PostgreSQL's optimizer can re-evaluate the plan based on the statistics. In other words, what might be a good query plan today probably won't be a good query plan for all time, and index hints force a particular query plan for all time.

As a very blunt hammer, useful for testing, you can use the enable_seqscan and enable_indexscan parameters. See:

These are not suitable for ongoing production use. If you have issues with query plan choice, you should see the documentation for tracking down query performance issues. Don't just set enable_ params and walk away.

Unless you have a very good reason for using the index, Postgres may be making the correct choice. Why?

For small tables, it's faster to do sequential scans.
Postgres doesn't use indexes when datatypes don't match properly, you may need to include appropriate casts.
Your planner settings might be causing problems.

Laravel where on relationship object

    return Deal::with(["redeem" => function($q){
        $q->where('user_id', '=', 1);
    }])->get();

this worked for me

What is C# analog of C++ std::pair?

Some answers seem just wrong,

you can't use dictionary how would store the pairs (a,b) and (a,c). Pairs concept should not be confused with associative look up of key and values
lot of the above code seems suspect

Here is my pair class

public class Pair<X, Y>
{
    private X _x;
    private Y _y;

    public Pair(X first, Y second)
    {
        _x = first;
        _y = second;
    }

    public X first { get { return _x; } }

    public Y second { get { return _y; } }

    public override bool Equals(object obj)
    {
        if (obj == null)
            return false;
        if (obj == this)
            return true;
        Pair<X, Y> other = obj as Pair<X, Y>;
        if (other == null)
            return false;

        return
            (((first == null) && (other.first == null))
                || ((first != null) && first.Equals(other.first)))
              &&
            (((second == null) && (other.second == null))
                || ((second != null) && second.Equals(other.second)));
    }

    public override int GetHashCode()
    {
        int hashcode = 0;
        if (first != null)
            hashcode += first.GetHashCode();
        if (second != null)
            hashcode += second.GetHashCode();

        return hashcode;
    }
}

Here is some test code:

[TestClass]
public class PairTest
{
    [TestMethod]
    public void pairTest()
    {
        string s = "abc";
        Pair<int, string> foo = new Pair<int, string>(10, s);
        Pair<int, string> bar = new Pair<int, string>(10, s);
        Pair<int, string> qux = new Pair<int, string>(20, s);
        Pair<int, int> aaa = new Pair<int, int>(10, 20);

        Assert.IsTrue(10 == foo.first);
        Assert.AreEqual(s, foo.second);
        Assert.AreEqual(foo, bar);
        Assert.IsTrue(foo.GetHashCode() == bar.GetHashCode());
        Assert.IsFalse(foo.Equals(qux));
        Assert.IsFalse(foo.Equals(null));
        Assert.IsFalse(foo.Equals(aaa));

        Pair<string, string> s1 = new Pair<string, string>("a", "b");
        Pair<string, string> s2 = new Pair<string, string>(null, "b");
        Pair<string, string> s3 = new Pair<string, string>("a", null);
        Pair<string, string> s4 = new Pair<string, string>(null, null);
        Assert.IsFalse(s1.Equals(s2));
        Assert.IsFalse(s1.Equals(s3));
        Assert.IsFalse(s1.Equals(s4));
        Assert.IsFalse(s2.Equals(s1));
        Assert.IsFalse(s3.Equals(s1));
        Assert.IsFalse(s2.Equals(s3));
        Assert.IsFalse(s4.Equals(s1));
        Assert.IsFalse(s1.Equals(s4));
    }
}

Tree implementation in Java (root, parents and children)

import java.util.ArrayList;
import java.util.List;

public class Node<T> {
    private List<Node<T>> children = new ArrayList<Node<T>>();
    private Node<T> parent = null;
    private T data = null;

    public Node(T data) {
        this.data = data;
    }

    public Node(T data, Node<T> parent) {
        this.data = data;
        this.parent = parent;
    }

    public List<Node<T>> getChildren() {
        return children;
    }

    public void setParent(Node<T> parent) {
        parent.addChild(this);
        this.parent = parent;
    }

    public void addChild(T data) {
        Node<T> child = new Node<T>(data);
        child.setParent(this);
        this.children.add(child);
    }

    public void addChild(Node<T> child) {
        child.setParent(this);
        this.children.add(child);
    }

    public T getData() {
        return this.data;
    }

    public void setData(T data) {
        this.data = data;
    }

    public boolean isRoot() {
        return (this.parent == null);
    }

    public boolean isLeaf() {
        return this.children.size == 0;
    }

    public void removeParent() {
        this.parent = null;
    }
}

Example:

import java.util.List;

Node<String> parentNode = new Node<String>("Parent"); 
Node<String> childNode1 = new Node<String>("Child 1", parentNode);
Node<String> childNode2 = new Node<String>("Child 2");     

childNode2.setParent(parentNode); 

Node<String> grandchildNode = new Node<String>("Grandchild of parentNode. Child of childNode1", childNode1); 
List<Node<String>> childrenNodes = parentNode.getChildren();

How can I ping a server port with PHP?

If you want to send ICMP packets in php you can take a look at this Native-PHP ICMP ping implementation, but I didn't test it.

EDIT:

Maybe the site was hacked because it seems that the files got deleted, there is copy in archive.org but you can't download the tar ball file, there are no contact email only contact form, but this will not work at archive.org, we can only wait until the owner will notice that sit is down.

How to declare empty list and then add string in scala?

As mentioned in an above answer, the Scala List is an immutable collection. You can create an empty list with .empty[A]. Then you can use a method :+ , +: or :: in order to add element to the list.

scala> val strList = List.empty[String]
strList: List[String] = List()

scala> strList:+ "Text"
res3: List[String] = List(Text)

scala> val mapList = List.empty[Map[String, Any]]
mapList: List[Map[String,Any]] = List()

scala> mapList :+ Map("1" -> "ok")
res4: List[Map[String,Any]] = List(Map(1 -> ok))

Sending files using POST with HttpURLConnection

based on Mihai's solution, if anyone has the problem of saving images on the server like what happened on my server. change the Bitmap to bytebuffer part to :

ByteArrayOutputStream bos = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.JPEG,100,bos);
        byte[] pixels = bos.toByteArray();

Pure CSS checkbox image replacement

Using javascript seems to be unnecessary if you choose CSS3.

By using :before selector, you can do this in two lines of CSS. (no script involved).

Another advantage of this approach is that it does not rely on <label> tag and works even it is missing.

Note: in browsers without CSS3 support, checkboxes will look normal. (backward compatible).

input[type=checkbox]:before { content:""; display:inline-block; width:12px; height:12px; background:red; }
input[type=checkbox]:checked:before { background:green; }?

You can see a demo here: http://jsfiddle.net/hqZt6/1/

and this one with images:

http://jsfiddle.net/hqZt6/6/

How to add New Column with Value to the Existing DataTable?

Without For loop:

Dim newColumn As New Data.DataColumn("Foo", GetType(System.String))     
newColumn.DefaultValue = "Your DropDownList value" 
table.Columns.Add(newColumn)

C#:

System.Data.DataColumn newColumn = new System.Data.DataColumn("Foo", typeof(System.String));
newColumn.DefaultValue = "Your DropDownList value";
table.Columns.Add(newColumn);

Adding files to a GitHub repository

The general idea is to add, commit and push your files to the GitHub repo.

First you need to clone your GitHub repo.
Then, you would git add all the files from your other folder: one trick is to specify an alternate working tree when git add'ing your files.

git --work-tree=yourSrcFolder add .

(done from the root directory of your cloned Git repo, then git commit -m "a msg", and git push origin master)

That way, you keep separate your initial source folder, from your Git working tree.

Note that since early December 2012, you can create new files directly from GitHub:

Create new File

ProTip™: You can pre-fill the filename field using just the URL.
Typing ?filename=yournewfile.txt at the end of the URL will pre-fill the filename field with the name yournewfile.txt.

Want custom title / image / description in facebook share link from a flash app

I actually have a similar problem. I have a page with multiple radio buttons; each button will set the title and description meta tags of the page, via JavaScript upon change.

For example, if users select the first button, the meta tags will say:

<meta name="title" content="First Title">
<meta name="description" content="First Description">

If the user select the second button, this changes the meta tags to:

<meta name="title" content="Second Title">
<meta name="description" content="Second Description">

... and so on. I have confirmed that the code is working fine via Firebug (i.e. I can see that those two tags were properly changed).

Apparently, Facebook Share only pulls in the title and description meta tags that are available upon page load. The changes to those two tags post page load are completely ignored.

Does anybody have any ideas on how to solve this? That is, to force Facebook to get the latest values that are change after the page loads.

How to delete all the rows in a table using Eloquent?

The reason MyModel::all()->delete() doesn't work is because all() actually fires off the query and returns a collection of Eloquent objects.

You can make use of the truncate method, this works for Laravel 4 and 5:

MyModel::truncate();

That drops all rows from the table without logging individual row deletions.

Call a function after previous function is complete

This depends on what function1 is doing.

If function1 is doing some simple synchrounous javascript, like updating a div value or something, then function2 will fire after function1 has completed.

If function1 is making an asynchronous call, such as an AJAX call, you will need to create a "callback" method (most ajax API's have a callback function parameter). Then call function2 in the callback. eg:

function1()
{
  new AjaxCall(ajaxOptions, MyCallback);
}

function MyCallback(result)
{
  function2(result);
}

JavaScript before leaving the page

Normally you want to show this message, when the user has made changes in a form, but they are not saved.

Take this approach to show a message, only when the user has changed something

var form = $('#your-form'),
  original = form.serialize()

form.submit(function(){
  window.onbeforeunload = null
})

window.onbeforeunload = function(){
  if (form.serialize() != original)
    return 'Are you sure you want to leave?'
}

Vendor code 17002 to connect to SQLDeveloper

I encountered same problem with ORACLE 11G express on Windows. After a long time waiting I got the same error message.

My solution is to make sure the hostname in tnsnames.ora (usually it's not "localhost") and the default hostname in sql developer(usually it's "localhost") same. You can either do this by changing it in the tnsnames.ora, or filling up the same in the sql developer.

Oh, of course you need to reboot all the oracle services (just to be safe).

Hope it helps.

I came across the similar problem again on another machine, but this time above solution doesn't work. After some trying, I found restarting all the oracle related services can fix the problem. Originally when the installation is done, connection can be made. Somehow after several reboot of computer, there is problem. I change all the oracle services with start time as auto. And once I could not connect, I restart them all over again (the core service should be restarted at last order), and works fine.

Some article says it might be due to the MTS problem. Microsoft's problem. Maybe!

Concat a string to SELECT * MySql

If you want to concatenate the fields using / as a separator, you can use concat_ws:

select concat_ws('/', col1, col2, col3) from mytable

You cannot escape listing the columns in the query though. The *-syntax works only in "select * from". You can list the columns and construct the query dynamically though.

matching query does not exist Error in Django

You may try this way. just use a function to get your object

def get_object(self, id):
    try:
        return UniversityDetails.objects.get(email__exact=email)
    except UniversityDetails.DoesNotExist:
        return False

Apache httpd setup and installation

jQuery .find() on data from .ajax() call is returning "[object Object]" instead of div

You might have to do something like

var content= (typeof response.d) == 'string' ? eval('(' + response.d + ')') : response.d

then you should be able to use

result = $(content).find("#result")

Error handling in Bash

Use a trap!

tempfiles=( )
cleanup() {
  rm -f "${tempfiles[@]}"
}
trap cleanup 0

error() {
  local parent_lineno="$1"
  local message="$2"
  local code="${3:-1}"
  if [[ -n "$message" ]] ; then
    echo "Error on or near line ${parent_lineno}: ${message}; exiting with status ${code}"
  else
    echo "Error on or near line ${parent_lineno}; exiting with status ${code}"
  fi
  exit "${code}"
}
trap 'error ${LINENO}' ERR

...then, whenever you create a temporary file:

temp_foo="$(mktemp -t foobar.XXXXXX)"
tempfiles+=( "$temp_foo" )

and $temp_foo will be deleted on exit, and the current line number will be printed. (set -e will likewise give you exit-on-error behavior, though it comes with serious caveats and weakens code's predictability and portability).

You can either let the trap call error for you (in which case it uses the default exit code of 1 and no message) or call it yourself and provide explicit values; for instance:

error ${LINENO} "the foobar failed" 2

will exit with status 2, and give an explicit message.

Unique Key constraints for multiple columns in Entity Framework

Completing @chuck answer for using composite indices with foreign keys.

You need to define a property that will hold the value of the foreign key. You can then use this property inside the index definition.

For example, we have company with employees and only we have a unique constraint on (name, company) for any employee:

class Company
{
    public Guid Id { get; set; }
}

class Employee
{
    public Guid Id { get; set; }
    [Required]
    public String Name { get; set; }
    public Company Company  { get; set; }
    [Required]
    public Guid CompanyId { get; set; }
}

Now the mapping of the Employee class:

class EmployeeMap : EntityTypeConfiguration<Employee>
{
    public EmployeeMap ()
    {
        ToTable("Employee");

        Property(p => p.Id)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);

        Property(p => p.Name)
            .HasUniqueIndexAnnotation("UK_Employee_Name_Company", 0);
        Property(p => p.CompanyId )
            .HasUniqueIndexAnnotation("UK_Employee_Name_Company", 1);
        HasRequired(p => p.Company)
            .WithMany()
            .HasForeignKey(p => p.CompanyId)
            .WillCascadeOnDelete(false);
    }
}

Note that I also used @niaher extension for unique index annotation.

Placing border inside of div and not on its edge

for consistent rendering between new and older browsers, add a double container, the outer with the width, the inner with the border.

<div style="width:100px;">
<div style="border:2px solid #000;">
contents here
</div>
</div>

this is obviously only if your precise width is more important than having extra markup!

Document Root PHP

The Easiest way to do it is to have good site structure and write it as a constant.

DEFINE("BACK_ROOT","/var/www/");

Validate decimal numbers in JavaScript - IsNumeric()

Yeah, the built-in isNaN(object) will be much faster than any regex parsing, because it's built-in and compiled, instead of interpreted on the fly.

Although the results are somewhat different to what you're looking for (try it):

                                              // IS NUMERIC
document.write(!isNaN('-1') + "<br />");      // true
document.write(!isNaN('-1.5') + "<br />");    // true
document.write(!isNaN('0') + "<br />");       // true
document.write(!isNaN('0.42') + "<br />");    // true
document.write(!isNaN('.42') + "<br />");     // true
document.write(!isNaN('99,999') + "<br />");  // false
document.write(!isNaN('0x89f') + "<br />");   // true
document.write(!isNaN('#abcdef') + "<br />"); // false
document.write(!isNaN('1.2.3') + "<br />");   // false
document.write(!isNaN('') + "<br />");        // true
document.write(!isNaN('blah') + "<br />");    // false

heroku - how to see all the logs

For cedar stack see:

https://devcenter.heroku.com/articles/oneoff-admin-ps

you need to run:

heroku run bash ...

casting int to char using C++ style casting

You should use static_cast<char>(i) to cast the integer i to char.

reinterpret_cast should almost never be used, unless you want to cast one type into a fundamentally different type.

Also reinterpret_cast is machine dependent so safely using it requires complete understanding of the types as well as how the compiler implements the cast.

For more information about C++ casting see:

How to add a default include path for GCC in Linux?

just a note: CPLUS_INCLUDE_PATH and C_INCLUDE_PATH are not the equivalent of LD_LIBRARY_PATH. LD_LIBRARY_PATH serves the ld (the dynamic linker at runtime) whereas the equivalent of the former two that serves your C/C++ compiler with the location of libraries is LIBRARY_PATH.

Django: OperationalError No Such Table

Running the following commands solved this for me 1. python manage.py migrate 2. python manage.py makemigrations 3. python manage.py makemigrations appName

How do I add a project as a dependency of another project?

Assuming the MyEjbProject is not another Maven Project you own or want to build with maven, you could use system dependencies to link to the existing jar file of the project like so

<project>
   ...
   <dependencies>
      <dependency>
         <groupId>yourgroup</groupId>
         <artifactId>myejbproject</artifactId>
         <version>2.0</version>
         <scope>system</scope>
         <systemPath>path/to/myejbproject.jar</systemPath>
      </dependency>
   </dependencies>
   ...
</project>

That said it is usually the better (and preferred way) to install the package to the repository either by making it a maven project and building it or installing it the way you already seem to do.

If they are, however, dependent on each other, you can always create a separate parent project (has to be a "pom" project) declaring the two other projects as its "modules". (The child projects would not have to declare the third project as their parent). As a consequence you'd get a new directory for the new parent project, where you'd also quite probably put the two independent projects like this:

parent
|- pom.xml
|- MyEJBProject
|   `- pom.xml
`- MyWarProject
    `- pom.xml

The parent project would get a "modules" section to name all the child modules. The aggregator would then use the dependencies in the child modules to actually find out the order in which the projects are to be built)

<project>
   ...
   <artifactId>myparentproject</artifactId>
   <groupId>...</groupId>
   <version>...</version>

   <packaging>pom</packaging>
   ...
   <modules>
     <module>MyEJBModule</module>
     <module>MyWarModule</module>
   </modules>
   ...
</project>

That way the projects can relate to each other but (once they are installed in the local repository) still be used independently as artifacts in other projects

Finally, if your projects are not in related directories, you might try to give them as relative modules:

filesystem
 |- mywarproject
 |   `pom.xml
 |- myejbproject
 |   `pom.xml
 `- parent
     `pom.xml

now you could just do this (worked in maven 2, just tried it):

<!--parent-->
<project>
  <modules>
    <module>../mywarproject</module>
    <module>../myejbproject</module>
  </modules>
</project>

Given a URL to a text file, what is the simplest way to read the contents of the text file?

import urllib2
for line in urllib2.urlopen("http://www.myhost.com/SomeFile.txt"):
    print line

Conversion failed when converting the varchar value to data type int in sql

I got the same error message. In my case, it was due to not using quotes.

Although the column was supposed to have only numbers, it was a Varchar column, and one of the rows had a letter in it.

So I was doing this:

select * from mytable where myid = 1234

While I should be doing this:

select * from mytable where myid = '1234'

If the column had all numbers, the conversion would have worked, but not in this case.

Exporting to .xlsx using Microsoft.Office.Interop.Excel SaveAs Error

Try changing the second parameter in the SaveAs call to Excel.XlFileFormat.xlWorkbookDefault.

When I did that, I generated an xlsx file that I was able to successfully open. (Before making the change, I could produce an xlsx file, but I was unable to open it.)

Also, I'm not sure if it matters or not, but I'm using the Excel 12.0 object library.

Usage of the backtick character (`) in JavaScript

This is a feature called template literals.

They were called "template strings" in prior editions of the ECMAScript 2015 specification.

Template literals are supported by Firefox 34, Chrome 41, and Edge 12 and above, but not by Internet Explorer.

Examples: http://tc39wiki.calculist.org/es6/template-strings/
Official specification: ECMAScript 2015 Language Specification, 12.2.9 Template Literal Lexical Components (a bit dry)

Template literals can be used to represent multi-line strings and may use "interpolation" to insert variables:

var a = 123, str = `---
   a is: ${a}
---`;
console.log(str);

Output:

---
   a is: 123
---

What is more important, they can contain not just a variable name, but any JavaScript expression:

var a = 3, b = 3.1415;

console.log(`PI is nearly ${Math.max(a, b)}`);

Export data from R to Excel

Recently used xlsx package, works well.

library(xlsx)
write.xlsx(x, file, sheetName="Sheet1")

where x is a data.frame

Speed comparison with Project Euler: C vs Python vs Erlang vs Haskell

Just for fun. The following is a more 'native' Haskell implementation:

import Control.Applicative
import Control.Monad
import Data.Either
import Math.NumberTheory.Powers.Squares

isInt :: RealFrac c => c -> Bool
isInt = (==) <$> id <*> fromInteger . round

intSqrt :: (Integral a) => a -> Int
--intSqrt = fromIntegral . floor . sqrt . fromIntegral
intSqrt = fromIntegral . integerSquareRoot'

factorize :: Int -> [Int]
factorize 1 = []
factorize n = first : factorize (quot n first)
  where first = (!! 0) $ [a | a <- [2..intSqrt n], rem n a == 0] ++ [n]

factorize2 :: Int -> [(Int,Int)]
factorize2 = foldl (\ls@((val,freq):xs) y -> if val == y then (val,freq+1):xs else (y,1):ls) [(0,0)] . factorize

numDivisors :: Int -> Int
numDivisors = foldl (\acc (_,y) -> acc * (y+1)) 1 <$> factorize2

nextTriangleNumber :: (Int,Int) -> (Int,Int)
nextTriangleNumber (n,acc) = (n+1,acc+n+1)

forward :: Int -> (Int, Int) -> Either (Int, Int) (Int, Int)
forward k val@(n,acc) = if numDivisors acc > k then Left val else Right (nextTriangleNumber val)

problem12 :: Int -> (Int, Int)
problem12 n = (!!0) . lefts . scanl (>>=) (forward n (1,1)) . repeat . forward $ n

main = do
  let (n,val) = problem12 1000
  print val

Using ghc -O3, this consistently runs in 0.55-0.58 seconds on my machine (1.73GHz Core i7).

A more efficient factorCount function for the C version:

int factorCount (int n)
{
  int count = 1;
  int candidate,tmpCount;
  while (n % 2 == 0) {
    count++;
    n /= 2;
  }
    for (candidate = 3; candidate < n && candidate * candidate < n; candidate += 2)
    if (n % candidate == 0) {
      tmpCount = 1;
      do {
        tmpCount++;
        n /= candidate;
      } while (n % candidate == 0);
       count*=tmpCount;
      }
  if (n > 1)
    count *= 2;
  return count;
}

Changing longs to ints in main, using gcc -O3 -lm, this consistently runs in 0.31-0.35 seconds.

Both can be made to run even faster if you take advantage of the fact that the nth triangle number = n*(n+1)/2, and n and (n+1) have completely disparate prime factorizations, so the number of factors of each half can be multiplied to find the number of factors of the whole. The following:

int main ()
{
  int triangle = 0,count1,count2 = 1;
  do {
    count1 = count2;
    count2 = ++triangle % 2 == 0 ? factorCount(triangle+1) : factorCount((triangle+1)/2);
  } while (count1*count2 < 1001);
  printf ("%lld\n", ((long long)triangle)*(triangle+1)/2);
}

will reduce the c code run time to 0.17-0.19 seconds, and it can handle much larger searches -- greater than 10000 factors takes about 43 seconds on my machine. I leave a similar haskell speedup to the interested reader.

How to convert a pymongo.cursor.Cursor into a dict?

The find method returns a Cursor instance, which allows you to iterate over all matching documents.

To get the first document that matches the given criteria you need to use find_one. The result of find_one is a dictionary.

You can always use the list constructor to return a list of all the documents in the collection but bear in mind that this will load all the data in memory and may not be what you want.

You should do that if you need to reuse the cursor and have a good reason not to use rewind()

Demo using find:

>>> import pymongo
>>> conn = pymongo.MongoClient()
>>> db = conn.test #test is my database
>>> col = db.spam #Here spam is my collection
>>> cur = col.find()  
>>> cur
<pymongo.cursor.Cursor object at 0xb6d447ec>
>>> for doc in cur:
...     print(doc)  # or do something with the document
... 
{'a': 1, '_id': ObjectId('54ff30faadd8f30feb90268f'), 'b': 2}
{'a': 1, 'c': 3, '_id': ObjectId('54ff32a2add8f30feb902690'), 'b': 2}

Demo using find_one:

>>> col.find_one()
{'a': 1, '_id': ObjectId('54ff30faadd8f30feb90268f'), 'b': 2}

Bulk insert with SQLAlchemy ORM

SQLAlchemy introduced that in version 1.0.0:

Bulk operations - SQLAlchemy docs

With these operations, you can now do bulk inserts or updates!

For instance (if you want the lowest overhead for simple table INSERTs), you can use Session.bulk_insert_mappings():

loadme = [(1, 'a'),
          (2, 'b'),
          (3, 'c')]
dicts = [dict(bar=t[0], fly=t[1]) for t in loadme]

s = Session()
s.bulk_insert_mappings(Foo, dicts)
s.commit()

Or, if you want, skip the loadme tuples and write the dictionaries directly into dicts (but I find it easier to leave all the wordiness out of the data and load up a list of dictionaries in a loop).

How can I perform a str_replace in JavaScript, replacing text in JavaScript?

Added a method replace_in_javascript which will satisfy your requirement. Also found that you are writing a string "new_text" in document.write() which is supposed to refer to a variable new_text.

_x000D_

let replace_in_javascript= (replaceble, replaceTo, text) => {_x000D_
  return text.replace(replaceble, replaceTo)_x000D_
}_x000D_
_x000D_
var text = "this is some sample text that i want to replace";_x000D_
var new_text = replace_in_javascript("want", "dont want", text);_x000D_
document.write(new_text);

_x000D_

Format Float to n decimal places

Take a look at DecimalFormat. You can easily use it to take a number and give it a set number of decimal places.

Edit: Example

Adding blur effect to background in swift

In a UIView extension:

func addBlurredBackground(style: UIBlurEffect.Style) {
    let blurEffect = UIBlurEffect(style: style)
    let blurView = UIVisualEffectView(effect: blurEffect)
    blurView.frame = self.frame
    blurView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
    self.addSubview(blurView)
    self.sendSubviewToBack(blurView)
}

Deleting an element from an array in PHP

You can use the array_pop method to remove the last element of an array:

<?php
    $a = array("one", "two", "Three");
    array_pop($a);
    print_r($a);
?>
The out put will be
Array ( [0] => one[1] => two)

which deletes only last element of an array LIFO operation

Remove duplicate elements from array in Ruby

array = array.uniq

uniq removes all duplicate elements and retains all unique elements in the array.

This is one of many beauties of the Ruby language.

How to do SVN Update on my project using the command line

If you want to update your project using SVN then first of all:

Go to the path on which your project is stored through command prompt.
Use the command SVN update

That's it.

anaconda - path environment variable in windows

Instead of giving the path following way:

C:\Users\User_name\AppData\Local\Continuum\anaconda3\python.exe

Do this:

C:\Users\User_name\AppData\Local\Continuum\anaconda3\

Reminder - \r\n or \n\r?

New line depends on your OS:

DOS & Windows: \r\n 0D0A (hex), 13,10 (decimal)
Unix & Mac OS X: \n, 0A, 10
Macintosh (OS 9): \r, 0D, 13

More details here: https://ccrma.stanford.edu/~craig/utility/flip/

When in doubt, use any freeware hex viewer/editor to see how a file encodes its new line.

For me, I use following guide to help me remember: 0D0A = \r\n = CR,LF = carriage return, line feed

Are the days of passing const std::string & as a parameter over?

The reason Herb said what he said is because of cases like this.

Let's say I have function A which calls function B, which calls function C. And A passes a string through B and into C. A does not know or care about C; all A knows about is B. That is, C is an implementation detail of B.

Let's say that A is defined as follows:

void A()
{
  B("value");
}

If B and C take the string by const&, then it looks something like this:

void B(const std::string &str)
{
  C(str);
}

void C(const std::string &str)
{
  //Do something with `str`. Does not store it.
}

All well and good. You're just passing pointers around, no copying, no moving, everyone's happy. C takes a const& because it doesn't store the string. It simply uses it.

Now, I want to make one simple change: C needs to store the string somewhere.

void C(const std::string &str)
{
  //Do something with `str`.
  m_str = str;
}

Hello, copy constructor and potential memory allocation (ignore the Short String Optimization (SSO)). C++11's move semantics are supposed to make it possible to remove needless copy-constructing, right? And A passes a temporary; there's no reason why C should have to copy the data. It should just abscond with what was given to it.

Except it can't. Because it takes a const&.

If I change C to take its parameter by value, that just causes B to do the copy into that parameter; I gain nothing.

So if I had just passed str by value through all of the functions, relying on std::move to shuffle the data around, we wouldn't have this problem. If someone wants to hold on to it, they can. If they don't, oh well.

Is it more expensive? Yes; moving into a value is more expensive than using references. Is it less expensive than the copy? Not for small strings with SSO. Is it worth doing?

It depends on your use case. How much do you hate memory allocations?

Converting JSON to XML in Java

Use the (excellent) JSON-Java library from json.org then

JSONObject json = new JSONObject(str);
String xml = XML.toString(json);

toString can take a second argument to provide the name of the XML root node.

This library is also able to convert XML to JSON using XML.toJSONObject(java.lang.String string)

Check the Javadoc

Link to the the github repository

POM

<dependency>
    <groupId>org.json</groupId>
    <artifactId>json</artifactId>
    <version>20160212</version>
</dependency>

original post updated with new links

Sorting Values of Set

If you sort the strings "12", "15" and "5" then "5" comes last because "5" > "1". i.e. the natural ordering of Strings doesn't work the way you expect.

If you want to store strings in your list but sort them numerically then you will need to use a comparator that handles this. e.g.

Collections.sort(list, new Comparator<String>() {
    public int compare(String o1, String o2) {
        Integer i1 = Integer.parseInt(o1);
        Integer i2 = Integer.parseInt(o2);
        return (i1 > i2 ? -1 : (i1 == i2 ? 0 : 1));
    }
});

Also, I think you are getting slightly mixed up between Collection types. A HashSet and a HashMap are different things.

Drop primary key using script in SQL Server database

The answer I got is that variables and subqueries will not work and we have to user dynamic SQL script. The following works:

DECLARE @SQL VARCHAR(4000)
SET @SQL = 'ALTER TABLE dbo.Student DROP CONSTRAINT |ConstraintName| '

SET @SQL = REPLACE(@SQL, '|ConstraintName|', ( SELECT   name
                                               FROM     sysobjects
                                               WHERE    xtype = 'PK'
                                                        AND parent_obj =        OBJECT_ID('Student')))

EXEC (@SQL)

What is causing "Unable to allocate memory for pool" in PHP?

Monitor your Cached Files Size (you can use apc.php from apc pecl package) and increase apc.shm_size according to your needs.

This solves the problem.

Convert int to a bit array in .NET

To convert your integer input to an array of bool of any size, just use LINQ.

bool[] ToBits(int input, int numberOfBits) {
    return Enumerable.Range(0, numberOfBits)
    .Select(bitIndex => 1 << bitIndex)
    .Select(bitMask => (input & bitMask) == bitMask)
    .ToArray();
}

So to convert an integer to a bool array of up to 32 bits, simply use it like so:

bool[] bits = ToBits(65, 8); // true, false, false, false, false, false, true, false

You may wish to reverse the array depending on your needs.

Array.Reverse(bits);

How to git-svn clone the last n revisions from a Subversion repository?

You've already discovered the simplest way to specify a shallow clone in Git-SVN, by specifying the SVN revision number that you want to start your clone at ( -r$REV:HEAD).

For example: git svn clone -s -r1450:HEAD some/svn/repo

Git's data structure is based on pointers in a directed acyclic graph (DAG), which makes it trivial to walk back n commits. But in SVN ( and therefore in Git-SVN) you will have to find the revision number yourself.

Sql select rows containing part of string

You can use the LIKE operator to compare the content of a T-SQL string, e.g.

SELECT * FROM [table] WHERE [field] LIKE '%stringtosearchfor%'.

The percent character '%' is a wild card- in this case it says return any records where [field] at least contains the value "stringtosearchfor".

how to access the command line for xampp on windows

Like all other had said above, you need to add path. But not sure for what reason if I add C:\xampp\php in path of System Variable won't work but if I add it in path of User Variable work fine.

Although I had added and using other command line tools by adding in system variables work fine

So just in case if someone had same problem as me. Windows 10

Jenkins vs Travis-CI. Which one would you use for a Open Source project?

I would suggest Travis for Open source project. It's just simple to configure and use.

Simple steps to setup:

Should have GITHUB account and register in Travis CI website using your GITHUB account.
Add .travis.yml file in root of your project. Add Travis as service in your repository settings page.

Now every time you commit into your repository Travis will build your project. You can follow simple steps to get started with Travis CI.

How to delete a workspace in Eclipse?

Click on the menu Window > Preferences and go to Workspaces like below :

| General
    | Startup and Shutdown
        | Workspaces

Select the workspace to delete and click on the Remove button.

How can I show a message box with two buttons?

It can be done, I found it elsewhere on the web...this is no way my work ! :)

    Option Explicit
' Import
Private Declare Function GetCurrentThreadId Lib "kernel32" () As Long

Private Declare Function SetDlgItemText Lib "user32" _
    Alias "SetDlgItemTextA" _
    (ByVal hDlg As Long, _
     ByVal nIDDlgItem As Long, _
     ByVal lpString As String) As Long

Private Declare Function SetWindowsHookEx Lib "user32" _
    Alias "SetWindowsHookExA" _
    (ByVal idHook As Long, _
     ByVal lpfn As Long, _
     ByVal hmod As Long, _
     ByVal dwThreadId As Long) As Long

Private Declare Function UnhookWindowsHookEx Lib "user32" _
    (ByVal hHook As Long) As Long

' Handle to the Hook procedure
Private hHook As Long

' Hook type
Private Const WH_CBT = 5
Private Const HCBT_ACTIVATE = 5

' Constants
Public Const IDOK = 1
Public Const IDCANCEL = 2
Public Const IDABORT = 3
Public Const IDRETRY = 4
Public Const IDIGNORE = 5
Public Const IDYES = 6
Public Const IDNO = 7

Public Sub MsgBoxSmile()
    ' Set Hook
    hHook = SetWindowsHookEx(WH_CBT, _
                             AddressOf MsgBoxHookProc, _
                             0, _
                             GetCurrentThreadId)

    ' Run MessageBox
    MsgBox "Smiling Message Box", vbYesNo, "Message Box Hooking"
End Sub

Private Function MsgBoxHookProc(ByVal lMsg As Long, _
                                ByVal wParam As Long, _
                                ByVal lParam As Long) As Long

    If lMsg = HCBT_ACTIVATE Then
        SetDlgItemText wParam, IDYES, "Yes   :-)"
        SetDlgItemText wParam, IDNO, "No   :-("

        ' Release the Hook
        UnhookWindowsHookEx hHook
    End If

    MsgBoxHookProc = False
End Function

Annotation @Transactional. How to rollback?

You can throw an unchecked exception from the method which you wish to roll back. This will be detected by spring and your transaction will be marked as rollback only.

I'm assuming you're using Spring here. And I assume the annotations you refer to in your tests are the spring test based annotations.

The recommended way to indicate to the Spring Framework's transaction infrastructure that a transaction's work is to be rolled back is to throw an Exception from code that is currently executing in the context of a transaction.

and note that:

please note that the Spring Framework's transaction infrastructure code will, by default, only mark a transaction for rollback in the case of runtime, unchecked exceptions; that is, when the thrown exception is an instance or subclass of RuntimeException.

How to allow CORS in react.js?

there are 6 ways to do this in React,

number 1 and 2 and 3 are the best:

1-config CORS in the Server-Side

2-set headers manually like this:

resonse_object.header("Access-Control-Allow-Origin", "*");
resonse_object.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");

3-config NGINX for proxy_pass which is explained here.

4-bypass the Cross-Origin-Policy with chrom extension(only for development and not recommended !)

5-bypass the cross-origin-policy with URL bellow(only for development)

"https://cors-anywhere.herokuapp.com/{type_your_url_here}"

6-use proxy in your package.json file:(only for development)

if this is your API: http://45.456.200.5:7000/api/profile/

add this part in your package.json file: "proxy": "http://45.456.200.5:7000/",

and then make your request with the next parts of the api:

React.useEffect(() => {
    axios
        .get('api/profile/')
        .then(function (response) {
            console.log(response);
        })
        .catch(function (error) {
            console.log(error);
        });
});

What is ADT? (Abstract Data Type)

ADT are a set of data values and associated operations that are precisely independent of any paticular implementaition. The strength of an ADT is implementaion is hidden from the user.only interface is declared .This means that the ADT is various ways

How to use makefiles in Visual Studio?

A UNIX guy probably told you that. :)

You can use makefiles in VS, but when you do it bypasses all the built-in functionality in MSVC's IDE. Makefiles are basically the reinterpret_cast of the builder. IMO the simplest thing is just to use Solutions.

AngularJs ReferenceError: $http is not defined

Just to complete Amit Garg answer, there are several ways to inject dependencies in AngularJS.

You can also use $inject to add a dependency:

var MyController = function($scope, $http) {
  // ...
}
MyController.$inject = ['$scope', '$http'];

Get Number of Rows returned by ResultSet in Java

You may think JDBC is a rich API and ResultSet has got so many methods then why not just a getCount() method? Well, For many databases e.g. Oracle, MySQL and SQL Server, ResultSet is a streaming API, this means that it does not load (or maybe even fetch) all the rows from the database server. By iterating to the end of the ResultSet you may add significantly to the time taken to execute in certain cases.

Btw, if you have to there are a couple of ways to do it e.g. by using ResultSet.last() and ResultSet.getRow() method, that's not the best way to do it but it works if you absolutely need it.

Though, getting the column count from a ResultSet is easy in Java. The JDBC API provides a ResultSetMetaData class which contains methods to return the number of columns returned by a query and hold by ResultSet.

How to force cp to overwrite without confirmation

-n is "not to overwrite" but his question is totally opposite what you replied for.

To avoid this confirmation you can simply run the cp command wiht absolute path, it will avoid the alias.

/bin/cp sourcefile destination

Find object in list that has attribute equal to some value (that meets any condition)

You could also implement rich comparison via __eq__ method for your Test class and use in operator. Not sure if this is the best stand-alone way, but in case if you need to compare Test instances based on value somewhere else, this could be useful.

class Test:
    def __init__(self, value):
        self.value = value

    def __eq__(self, other):
        """To implement 'in' operator"""
        # Comparing with int (assuming "value" is int)
        if isinstance(other, int):
            return self.value == other
        # Comparing with another Test object
        elif isinstance(other, Test):
            return self.value == other.value

import random

value = 5

test_list = [Test(random.randint(0,100)) for x in range(1000)]

if value in test_list:
    print "i found it"

script to map network drive

Here a JScript variant of JohnB's answer

// Below the MSDN page for MapNetworkDrive Method with link and in case if Microsoft breaks it like every now and then the path to the documentation of now.
// https://msdn.microsoft.com/en-us/library/8kst88h6(v=vs.84).aspx
// MSDN Library -> Web Development -> Scripting -> JScript and VBScript -> Windows Scripting -> Windows Script Host -> Reference (Windows Script Host) -> Methods (Windows Script Host) -> MapNetworkDrive Method

var WshNetwork = WScript.CreateObject('WScript.Network');
function localNameInUse(localName) {
    var driveIterator = WshNetwork.EnumNetworkDrives();
    for (var i=0, l=driveIterator.length; i < l; i += 2) {
        if (driveIterator.Item(i) == localName) {
            return true;
        }
    }
    return false;
}

function mount(localName, remoteName) {
    if (localNameInUse(localName)) {
        WScript.Echo('"' + localName + '" drive letter already in use.');
    } else {
        WshNetwork.MapNetworkDrive(localName, remoteName);
    }
}

function unmount(localName) {
    if (localNameInUse(localName)) {
        WshNetwork.RemoveNetworkDrive(localName);
    }
}

Adding headers when using httpClient.GetAsync

You can add whatever headers you need to the HttpClient.

Here is a nice tutorial about it.

This doesn't just reference to POST-requests, you can also use it for GET-requests.

How do MySQL indexes work?

Let's suppose you have a book, probably a novel, a thick one with lots of things to read, hence lots of words. Now, hypothetically, you brought two dictionaries, consisting of only words that are only used, at least one time in the novel. All words in that two dictionaries are stored in typical alphabetical order. In hypothetical dictionary A, words are printed only once while in hypothetical dictionary B words are printed as many numbers of times it is printed in the novel. Remember, words are sorted alphabetically in both the dictionaries. Now you got stuck at some point while reading a novel and need to find the meaning of that word from anyone of those hypothetical dictionaries. What you will do? Surely you will jump to that word in a few steps to find its meaning, rather look for the meaning of each of the words in the novel, from starting, until you reach that bugging word.

This is how the index works in SQL. Consider Dictionary A as PRIMARY INDEX, Dictionary B as KEY/SECONDARY INDEX, and your desire to get for the meaning of the word as a QUERY/SELECT STATEMENT. The index will help to fetch the data at a very fast rate. Without an index, you will have to look for the data from the starting, unnecessarily time-consuming costly task.

For more about indexes and types, look this.

open read and close a file in 1 line of code

I frequently do something like this when I need to get a few lines surrounding something I've grepped in a log file:

$ grep -n "xlrd" requirements.txt | awk -F ":" '{print $1}'
54

$ python -c "with open('requirements.txt') as file: print ''.join(file.readlines()[52:55])"
wsgiref==0.1.2
xlrd==0.9.2
xlwt==0.7.5

IntelliJ shortcut to show a popup of methods in a class that can be searched

I prefer to use the Structure view. To open it, use the menu: View/Tools Window/Structure. The hotkey on Windows is Alt+7

How to save a PNG image server-side, from a base64 data string

It worth to say that discussed topic is documented in RFC 2397 - The "data" URL scheme (https://tools.ietf.org/html/rfc2397)

Because of this PHP has a native way to handle such data - "data: stream wrapper" (http://php.net/manual/en/wrappers.data.php)

So you can easily manipulate your data with PHP streams:

$data = 'data:image/gif;base64,R0lGODlhEAAOALMAAOazToeHh0tLS/7LZv/0jvb29t/f3//Ub//ge8WSLf/rhf/3kdbW1mxsbP//mf///yH5BAAAAAAALAAAAAAQAA4AAARe8L1Ekyky67QZ1hLnjM5UUde0ECwLJoExKcppV0aCcGCmTIHEIUEqjgaORCMxIC6e0CcguWw6aFjsVMkkIr7g77ZKPJjPZqIyd7sJAgVGoEGv2xsBxqNgYPj/gAwXEQA7';

$source = fopen($data, 'r');
$destination = fopen('image.gif', 'w');

stream_copy_to_stream($source, $destination);

fclose($source);
fclose($destination);

How to resolve ambiguous column names when retrieving results?

When using PDO for a database interacttion, one can use the PDO::FETCH_NAMED fetch mode that could help to resolve the issue:

$sql = "SELECT * FROM news JOIN users ON news.user = user.id";
$data = $pdo->query($sql)->fetchAll(PDO::FETCH_NAMED);
foreach ($data as $row) {
    echo $row['column-name'][0]; // from the news table
    echo $row['column-name'][1]; // from the users table
    echo $row['other-column']; // any unique column name
}

How to determine if a point is in a 2D triangle?

Java version of barycentric method:

class Triangle {
    Triangle(double x1, double y1, double x2, double y2, double x3,
            double y3) {
        this.x3 = x3;
        this.y3 = y3;
        y23 = y2 - y3;
        x32 = x3 - x2;
        y31 = y3 - y1;
        x13 = x1 - x3;
        det = y23 * x13 - x32 * y31;
        minD = Math.min(det, 0);
        maxD = Math.max(det, 0);
    }

    boolean contains(double x, double y) {
        double dx = x - x3;
        double dy = y - y3;
        double a = y23 * dx + x32 * dy;
        if (a < minD || a > maxD)
            return false;
        double b = y31 * dx + x13 * dy;
        if (b < minD || b > maxD)
            return false;
        double c = det - a - b;
        if (c < minD || c > maxD)
            return false;
        return true;
    }

    private final double x3, y3;
    private final double y23, x32, y31, x13;
    private final double det, minD, maxD;
}

The above code will work accurately with integers, assuming no overflows. It will also work with clockwise and anticlockwise triangles. It will not work with collinear triangles (but you can check for that by testing det==0).

The barycentric version is fastest if you are going to test different points with the same triangle.

The barycentric version is not symmetric in the 3 triangle points, so it is likely to be less consistent than Kornel Kisielewicz's edge half-plane version, because of floating point rounding errors.

Credit: I made the above code from Wikipedia's article on barycentric coordinates.

Gradle Sync failed could not find constraint-layout:1.0.0-alpha2

My problem was, that the SDK Tools updated it to the latest version, in my case it was 1.0.0-alpha9, but in my gradle dependency was set to

compile 'com.android.support.constraint:constraint-layout:1.0.0-alpha8' So, you can change your gradle build file to

compile 'com.android.support.constraint:constraint-layout:1.0.0-alpha9' Or you check "Show package details" in the SDK Tools Editor and install your needed version. See screenshow below. Image of SDK Tools

The filename, directory name, or volume label syntax is incorrect inside batch

set myPATH="C:\Users\DEB\Downloads\10.1.1.0.4"
cd %myPATH%

The single quotes do not indicate a string, they make it starts: 'C:\ instead of C:\ so
%name% is the usual syntax for expanding a variable, the !name! syntax needs to be enabled using the command setlocal ENABLEDELAYEDEXPANSION first, or by running the command prompt with CMD /V:ON.
Don't use PATH as your name, it is a system name that contains all the locations of executable programs. If you overwrite it, random bits of your script will stop working. If you intend to change it, you need to do set PATH=%PATH%;C:\Users\DEB\Downloads\10.1.1.0.4 to keep the current PATH content, and add something to the end.

How to loop through a directory recursively to delete files with certain extensions

As a followup to mouviciel's answer, you could also do this as a for loop, instead of using xargs. I often find xargs cumbersome, especially if I need to do something more complicated in each iteration.

for f in $(find /tmp -name '*.pdf' -or -name '*.doc'); do rm $f; done

As a number of people have commented, this will fail if there are spaces in filenames. You can work around this by temporarily setting the IFS (internal field seperator) to the newline character. This also fails if there are wildcard characters \[?* in the file names. You can work around that by temporarily disabling wildcard expansion (globbing).

IFS=$'\n'; set -f
for f in $(find /tmp -name '*.pdf' -or -name '*.doc'); do rm "$f"; done
unset IFS; set +f

If you have newlines in your filenames, then that won't work either. You're better off with an xargs based solution:

find /tmp \( -name '*.pdf' -or -name '*.doc' \) -print0 | xargs -0 rm

(The escaped brackets are required here to have the -print0 apply to both or clauses.)

GNU and *BSD find also has a -delete action, which would look like this:

find /tmp \( -name '*.pdf' -or -name '*.doc' \) -delete

Can I set variables to undefined or pass undefined as an argument?

The for if (something) and if (!something) is commonly used to check if something is defined or not defined. For example:

if (document.getElementById)

The identifier is converted to a boolean value, so undefined is interpreted as false. There are of course other values (like 0 and '') that also are interpreted as false, but either the identifier should not reasonably have such a value or you are happy with treating such a value the same as undefined.

Javascript has a delete operator that can be used to delete a member of an object. Depending on the scope of a variable (i.e. if it's global or not) you can delete it to make it undefined.

There is no undefined keyword that you can use as an undefined literal. You can omit parameters in a function call to make them undefined, but that can only be used by sending less paramters to the function, you can't omit a parameter in the middle.

De-obfuscate Javascript code to make it readable again

Here it is:

function call_func(input) {
    var evaled = eval('(' + input + ')');
    var newDiv = document.createElement('div');
    var id = evaled.id;
    var name = evaled.Student_name;
    var dob = evaled.student_dob;
    var html = '<b>ID:</b>';
    html += '<a href="/learningyii/index.php?r=student/view&amp; id=' + id + '">' + id + '</a>';
    html += '<br/>';
    html += '<b>Student Name:</b>';
    html += name;
    html += '<br/>';
    html += '<b>Student DOB:</b>';
    html += dob;
    html += '<br/>';
    newDiv.innerHTML = html;
    newDiv.setAttribute('class', 'view');
    $('#StudentGridViewId').find('.items').prepend(newDiv);
};

Add CSS or JavaScript files to layout head from views or partial views

Here is a NuGet plugin called Cassette, which among other things provides you the ability to reference scripts and styles in partials.

Though there are a number of configurations available for this plugin, which makes it highly flexible. Here is the simplest way of referring script or stylesheet files:

Bundles.Reference("scripts/app");

According to the documentation:

Calls to Reference can appear anywhere in a page, layout or partial view.

The path argument can be one of the following:

A bundle path

An asset path - the whole bundle containing this asset is referenced

A URL

How do I parallelize a simple Python loop?

thanks @iuryxavier

from multiprocessing import Pool
from multiprocessing import cpu_count


def add_1(x):
    return x + 1

if __name__ == "__main__":
    pool = Pool(cpu_count())
    results = pool.map(add_1, range(10**12))
    pool.close()  # 'TERM'
    pool.join()   # 'KILL'

How to add data validation to a cell using VBA

Use this one:

Dim ws As Worksheet
Dim range1 As Range, rng As Range
'change Sheet1 to suit
Set ws = ThisWorkbook.Worksheets("Sheet1")

Set range1 = ws.Range("A1:A5")
Set rng = ws.Range("B1")

With rng.Validation
    .Delete 'delete previous validation
    .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, _
        Formula1:="='" & ws.Name & "'!" & range1.Address
End With

Note that when you're using Dim range1, rng As range, only rng has type of Range, but range1 is Variant. That's why I'm using Dim range1 As Range, rng As Range.
About meaning of parameters you can read is MSDN, but in short:

Type:=xlValidateList means validation type, in that case you should select value from list
AlertStyle:=xlValidAlertStop specifies the icon used in message boxes displayed during validation. If user enters any value out of list, he/she would get error message.
in your original code, Operator:= xlBetween is odd. It can be used only if two formulas are provided for validation.
Formula1:="='" & ws.Name & "'!" & range1.Address for list data validation provides address of list with values (in format =Sheet!A1:A5)

Hibernate: Automatically creating/updating the db tables based on entity classes

I don't know if leaving hibernate off the front makes a difference.

The reference suggests it should be hibernate.hbm2ddl.auto

A value of create will create your tables at sessionFactory creation, and leave them intact.

A value of create-drop will create your tables, and then drop them when you close the sessionFactory.

Perhaps you should set the javax.persistence.Table annotation explicitly?

Hope this helps.

How can I use a for each loop on an array?

I use the counter variable like Fink suggests. If you want For Each and to pass ByRef (which can be more efficient for long strings) you have to cast your element as a string using CStr

Sub Example()

    Dim vItm As Variant
    Dim aStrings(1 To 4) As String

    aStrings(1) = "one": aStrings(2) = "two": aStrings(3) = "three": aStrings(4) = "four"

    For Each vItm In aStrings
        do_something CStr(vItm)
    Next vItm

End Sub

Function do_something(ByRef sInput As String)

    Debug.Print sInput

End Function

ASP.NET MVC Bundle not rendering script files on staging server. It works on development server

Whenever I set debug="off" in my web.config and run my mvc4 application i would end up with ...

<script src="/bundles/jquery?v=<some long string>"></script>

in my html code and a JavaScript error

Expected ';'

There were 2 ways to get rid of the javascript error

set BundleTable.EnableOptimizations = false in BundleConfig.cs

I ended up using NuGet Package Manager to update WebGrease.dll. It works fine irrespective if debug= "true" or debug = "false".

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.h or .hpp for your class definitions