Programs & Examples On #Sieve of atkin

A modern prime number sieve with better computational complexity than that of the sieve of Eratosthenes.

Javascript: How to remove the last character from a div or a string?

$('#mainn').text(function (_,txt) {
    return txt.slice(0, -1);
});

demo --> http://jsfiddle.net/d72ML/8/

Set Focus on EditText

new OnEditorActionListener(){
   @Override
   public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
      editText.requestFocus();
      //used ******* return true ******
      return **true**;
   }
} 

How do you implement a Stack and a Queue in JavaScript?

If you wanted to make your own data structures, you could build your own:

var Stack = function(){
  this.top = null;
  this.size = 0;
};

var Node = function(data){
  this.data = data;
  this.previous = null;
};

Stack.prototype.push = function(data) {
  var node = new Node(data);

  node.previous = this.top;
  this.top = node;
  this.size += 1;
  return this.top;
};

Stack.prototype.pop = function() {
  temp = this.top;
  this.top = this.top.previous;
  this.size -= 1;
  return temp;
};

And for queue:

var Queue = function() {
  this.first = null;
  this.size = 0;
};

var Node = function(data) {
  this.data = data;
  this.next = null;
};

Queue.prototype.enqueue = function(data) {
  var node = new Node(data);

  if (!this.first){
    this.first = node;
  } else {
    n = this.first;
    while (n.next) {
      n = n.next;
    }
    n.next = node;
  }

  this.size += 1;
  return node;
};

Queue.prototype.dequeue = function() {
  temp = this.first;
  this.first = this.first.next;
  this.size -= 1;
  return temp;
};

Getting hold of the outer class object from the inner class object

Here's the example:

// Test
public void foo() {
    C c = new C();
    A s;
    s = ((A.B)c).get();
    System.out.println(s.getR());
}

// classes
class C {}

class A {
   public class B extends C{
     A get() {return A.this;}
   }
   public String getR() {
     return "This is string";
   }
}

BACKUP LOG cannot be performed because there is no current database backup

  1. Make sure there is a new database.
  2. Make sure you have access to your database (user, password etc).
  3. Make sure there is a backup file with no error in it.

Hope this can help you.

When to use %r instead of %s in Python?

Use the %r for debugging, since it displays the "raw" data of the variable, but the others are used for displaying to users.

That's how %r formatting works; it prints it the way you wrote it (or close to it). It's the "raw" format for debugging. Here \n used to display to users doesn't work. %r shows the representation if the raw data of the variable.

months = "\nJan\nFeb\nMar\nApr\nMay\nJun\nJul\nAug"
print "Here are the months: %r" % months

Output:

Here are the months: '\nJan\nFeb\nMar\nApr\nMay\nJun\nJul\nAug'

Check this example from Learn Python the Hard Way.

HTTP Status 404 - The requested resource (/) is not available

In my case, I've had to click on my project, then go to File > Properties > *servlet name* and click Restart servlet.

How to find out what type of a Mat object is with Mat::type() in OpenCV

I've added some usability to the function from the answer by @Octopus, for debugging purposes.

void MatType( Mat inputMat )
{
    int inttype = inputMat.type();

    string r, a;
    uchar depth = inttype & CV_MAT_DEPTH_MASK;
    uchar chans = 1 + (inttype >> CV_CN_SHIFT);
    switch ( depth ) {
        case CV_8U:  r = "8U";   a = "Mat.at<uchar>(y,x)"; break;  
        case CV_8S:  r = "8S";   a = "Mat.at<schar>(y,x)"; break;  
        case CV_16U: r = "16U";  a = "Mat.at<ushort>(y,x)"; break; 
        case CV_16S: r = "16S";  a = "Mat.at<short>(y,x)"; break; 
        case CV_32S: r = "32S";  a = "Mat.at<int>(y,x)"; break; 
        case CV_32F: r = "32F";  a = "Mat.at<float>(y,x)"; break; 
        case CV_64F: r = "64F";  a = "Mat.at<double>(y,x)"; break; 
        default:     r = "User"; a = "Mat.at<UKNOWN>(y,x)"; break; 
    }   
    r += "C";
    r += (chans+'0');
    cout << "Mat is of type " << r << " and should be accessed with " << a << endl;

}

Can Flask have optional URL parameters?

Since Flask 0.10 you can`t add multiple routes to one endpoint. But you can add fake endpoint

@user.route('/<userId>')
def show(userId):
   return show_with_username(userId)

@user.route('/<userId>/<username>')
def show_with_username(userId,username=None):
   pass

Spring security CORS Filter

Ok, after over 2 days of searching we finally fixed the problem. We deleted all our filter and configurations and instead used this 5 lines of code in the application class.

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        final ApplicationContext ctx = SpringApplication.run(Application.class, args);
    }

    @Bean
    public WebMvcConfigurer corsConfigurer() {
        return new WebMvcConfigurerAdapter() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
                registry.addMapping("/**").allowedOrigins("http://localhost:3000");
            }
        };
    }
}

What does an exclamation mark before a cell reference mean?

When entered as the reference of a Named range, it refers to range on the sheet the named range is used on.

For example, create a named range MyName refering to =SUM(!B1:!K1)

Place a formula on Sheet1 =MyName. This will sum Sheet1!B1:K1

Now place the same formula (=MyName) on Sheet2. That formula will sum Sheet2!B1:K1

Note: (as pnuts commented) this and the regular SheetName!B1:K1 format are relative, so reference different cells as the =MyName formula is entered into different cells.

Show popup after page load

When the DOM is finished loading you can add your code in the $(document).ready() function.

Remove the onclick from here:

<input type="submit" name="submit" value="Submit" onClick="PopUp()" />

Try this:

$(document).ready(function(){
   setTimeout(function(){
      PopUp();
   },5000); // 5000 to load it after 5 seconds from page load
});

Format an Integer using Java String Format

String.format("%03d", 1)  // => "001"
//              ¦¦¦   +-- print the number one
//              ¦¦+------ ... as a decimal integer
//              ¦+------- ... minimum of 3 characters wide
//              +-------- ... pad with zeroes instead of spaces

See java.util.Formatter for more information.

How to get POSTed JSON in Flask?

Try to use force parameter...

request.get_json(force = True)

File URL "Not allowed to load local resource" in the Internet Browser

For people do not like to modify chrome's security options, we can simply start a python http server from directory which contains your local file:

python -m SimpleHTTPServer

and for python 3:

python3 -m http.server

Now you can reach any local file directly from your js code or externally with http://127.0.0.1:8000/some_file.txt

Maven: How to rename the war file for the project?

You can follow the below step to modify the .war file name if you are using maven project.

Open pom.xml file of your maven project and go to the tag <build></build>,

  1. In that give your desired name between this tag : <finalName></finalName>.

    ex. : <finalName>krutik</finalName>

    After deploying this .war you will be able to access url with:
    http://localhost:8080/krutik/

  2. If you want to access the url with slash '/' then you will have to specify then name as below:

    e.x. : <finalName>krutik#maheta</finalName>

    After deploying this .war you will be able to access url with:
    http://localhost:8080/krutik/maheta

HTTP post XML data in C#

In General:

An example of an easy way to post XML data and get the response (as a string) would be the following function:

public string postXMLData(string destinationUrl, string requestXml)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(destinationUrl);
    byte[] bytes;
    bytes = System.Text.Encoding.ASCII.GetBytes(requestXml);
    request.ContentType = "text/xml; encoding='utf-8'";
    request.ContentLength = bytes.Length;
    request.Method = "POST";
    Stream requestStream = request.GetRequestStream();
    requestStream.Write(bytes, 0, bytes.Length);
    requestStream.Close();
    HttpWebResponse response;
    response = (HttpWebResponse)request.GetResponse();
    if (response.StatusCode == HttpStatusCode.OK)
    {
        Stream responseStream = response.GetResponseStream();
        string responseStr = new StreamReader(responseStream).ReadToEnd();
        return responseStr;
    }
    return null;
}

In your specific situation:

Instead of:

request.ContentType = "application/x-www-form-urlencoded";

use:

request.ContentType = "text/xml; encoding='utf-8'";

Also, remove:

string postData = "XMLData=" + Sendingxml;

And replace:

byte[] byteArray = Encoding.UTF8.GetBytes(postData);

with:

byte[] byteArray = Encoding.UTF8.GetBytes(Sendingxml.ToString());

How to get the date and time values in a C program?

One liner to get local time information: struct tm *tinfo = localtime(&(time_t){time(NULL)});

Switch android x86 screen resolution

Based on my experience, it's enough to use the following additional boot options:

UVESA_MODE=320x480 DPI=160

No need to add vga definition. Watch out for DPI value! As bigger one makes your icons bigger.

To add the previous boot options, go to debug mode (during grub menu selection)

mount -o remount,rw /mnt
vi /mnt/grub/menu.lst

Now edit on this line:

kernel /android-2.3-RC1/kernel quiet root=/dev/ram0 androidboot_hardware=eeepc acpi_sleep=s3_bios,s3_mode SRC=/android-2.3-RC1 SDCARD=/data/sdcard.img UVESA_MODE=320x480 DPI=160

Reboot

onclick on a image to navigate to another page using Javascript

I'd set up your HTML like so:

<img src="../images/bottle.jpg" alt="bottle" class="thumbnails" id="bottle" />

Then use the following code:

<script>
var images = document.getElementsByTagName("img");
for(var i = 0; i < images.length; i++) {
    var image = images[i];
    image.onclick = function(event) {
         window.location.href = this.id + '.html';
    };
}
</script>

That assigns an onclick event handler to every image on the page (this may not be what you want, you can limit it further if necessary) that changes the current page to the value of the images id attribute plus the .html extension. It's essentially the pure Javascript implementation of @JanPöschko's jQuery answer.

bootstrap 4 file input doesn't show the file name

If you want you can use the recommended Bootstrap plugin to dynamize your custom file input: https://www.npmjs.com/package/bs-custom-file-input

This plugin can be use with or without jQuery and works with React an Angular

What's a quick way to comment/uncomment lines in Vim?

I have the following in my .vimrc:

" Commenting blocks of code.
augroup commenting_blocks_of_code
  autocmd!
  autocmd FileType c,cpp,java,scala let b:comment_leader = '// '
  autocmd FileType sh,ruby,python   let b:comment_leader = '# '
  autocmd FileType conf,fstab       let b:comment_leader = '# '
  autocmd FileType tex              let b:comment_leader = '% '
  autocmd FileType mail             let b:comment_leader = '> '
  autocmd FileType vim              let b:comment_leader = '" '
augroup END
noremap <silent> ,cc :<C-B>silent <C-E>s/^/<C-R>=escape(b:comment_leader,'\/')<CR>/<CR>:nohlsearch<CR>
noremap <silent> ,cu :<C-B>silent <C-E>s/^\V<C-R>=escape(b:comment_leader,'\/')<CR>//e<CR>:nohlsearch<CR>

Now you can type ,cc to comment a line and ,cu to uncomment a line (works both in normal and visual mode).

(I stole it from some website many years ago so I can't completely explain how it works anymore :). There is a comment where it is explained.)

Java program to connect to Sql Server and running the sample query From Eclipse

Refer the below link.

There are two important changes that you should make

driver name as "com.microsoft.sqlserver.jdbc.SQLServerDriver"

& in URL "jdbc:sqlserver://localhost:1433"+";databaseName=AdventureWorks2008R2"

http://www.programcreek.com/2010/05/java-code-for-connecting-ms-sql-server-by-using-sql-server-authentication/

How to return multiple values?

You can return an object of a Class in Java.

If you are returning more than 1 value that are related, then it makes sense to encapsulate them into a class and then return an object of that class.

If you want to return unrelated values, then you can use Java's built-in container classes like Map, List, Set etc. Check the java.util package's JavaDoc for more details.

In HTML I can make a checkmark with &#x2713; . Is there a corresponding X-mark?

Personally, I like to use named entities when they are available, because they make my HTML more readable. Because of that, I like to use &check; for ✓ and &cross; for ✗. If you're not sure whether a named entity exists for the character you want, try the &what search site. It includes the name for each entity, if there is one.

As mentioned in the comments, &check; and &cross; are not supported in HTML4, so you may be better off using the more cryptic &#x2713; and &#x2717; if you want to target the most browsers. The most definitive references I could find were on the W3C site: HTML4 and HTML5.

Best way to parse RSS/Atom feeds with PHP

If feed isn't well-formed XML, you're supposed to reject it, no exceptions. You're entitled to call feed creator a bozo.

Otherwise you're paving way to mess that HTML ended up in.

Unzipping files

I found jszip quite useful. I've used so far only for reading, but they have create/edit capabilities as well.

Code wise it looks something like this

var new_zip = new JSZip();
new_zip.load(file);
new_zip.files["doc.xml"].asText() // this give you the text in the file

One thing I noticed is that it seems the file has to be in binary stream format (read using the .readAsArrayBuffer of FileReader(), otherwise I was getting errors saying I might have a corrupt zip file

Edit: Note from the 2.x to 3.0.0 upgrade guide:

The load() method and the constructor with data (new JSZip(data)) have been replaced by loadAsync().

Thanks user2677034

Determine if $.ajax error is a timeout

If your error event handler takes the three arguments (xmlhttprequest, textstatus, and message) when a timeout happens, the status arg will be 'timeout'.

Per the jQuery documentation:

Possible values for the second argument (besides null) are "timeout", "error", "notmodified" and "parsererror".

You can handle your error accordingly then.

I created this fiddle that demonstrates this.

$.ajax({
    url: "/ajax_json_echo/",
    type: "GET",
    dataType: "json",
    timeout: 1000,
    success: function(response) { alert(response); },
    error: function(xmlhttprequest, textstatus, message) {
        if(textstatus==="timeout") {
            alert("got timeout");
        } else {
            alert(textstatus);
        }
    }
});?

With jsFiddle, you can test ajax calls -- it will wait 2 seconds before responding. I put the timeout setting at 1 second, so it should error out and pass back a textstatus of 'timeout' to the error handler.

Hope this helps!

Easiest way to read from and write to files

FileStream fs = new FileStream(txtSourcePath.Text,FileMode.Open, FileAccess.Read);
using(StreamReader sr = new StreamReader(fs))
{
   using (StreamWriter sw = new StreamWriter(Destination))
   {
            sw.writeline("Your text");
    }
}

Python Key Error=0 - Can't find Dict error in code

The error you're getting is that self.adj doesn't already have a key 0. You're trying to append to a list that doesn't exist yet.

Consider using a defaultdict instead, replacing this line (in __init__):

self.adj = {}

with this:

self.adj = defaultdict(list)

You'll need to import at the top:

from collections import defaultdict

Now rather than raise a KeyError, self.adj[0].append(edge) will create a list automatically to append to.

How can I check if a MySQL table exists with PHP?

You can use many different queries to check if a table exists. Below is a comparison between several:

mysql_query('select 1 from `table_name` group by 1'); or  
mysql_query('select count(*) from `table_name`');

mysql_query("DESCRIBE `table_name`");  
70000   rows: 24ms  
1000000 rows: 24ms  
5000000 rows: 24ms

mysql_query('select 1 from `table_name`');  
70000   rows: 19ms  
1000000 rows: 23ms  
5000000 rows: 29ms

mysql_query('select 1 from `table_name` group by 1'); or  
mysql_query('select count(*) from `table_name`');  
70000   rows: 18ms  
1000000 rows: 18ms  
5000000 rows: 18ms  

These benchmarks are only averages:

How can I create a war file of my project in NetBeans?

Right click your project, hit "Clean and Build". Netbeans does the rest.

under the dist directory of your app, you should find a pretty looking .war all ready for deployment.

What is a blob URL and why it is used?

Blob URLs (ref W3C, official name) or Object-URLs (ref. MDN and method name) are used with a Blob or a File object.

src="blob:https://crap.crap" I opened the blob url that was in src of video it gave a error and i can't open but was working with the src tag how it is possible?

Blob URLs can only be generated internally by the browser. URL.createObjectURL() will create a special reference to the Blob or File object which later can be released using URL.revokeObjectURL(). These URLs can only be used locally in the single instance of the browser and in the same session (ie. the life of the page/document).

What is blob url?
Why it is used?

Blob URL/Object URL is a pseudo protocol to allow Blob and File objects to be used as URL source for things like images, download links for binary data and so forth.

For example, you can not hand an Image object raw byte-data as it would not know what to do with it. It requires for example images (which are binary data) to be loaded via URLs. This applies to anything that require an URL as source. Instead of uploading the binary data, then serve it back via an URL it is better to use an extra local step to be able to access the data directly without going via a server.

It is also a better alternative to Data-URI which are strings encoded as Base-64. The problem with Data-URI is that each char takes two bytes in JavaScript. On top of that a 33% is added due to the Base-64 encoding. Blobs are pure binary byte-arrays which does not have any significant overhead as Data-URI does, which makes them faster and smaller to handle.

Can i make my own blob url on a server?

No, Blob URLs/Object URLs can only be made internally in the browser. You can make Blobs and get File object via the File Reader API, although BLOB just means Binary Large OBject and is stored as byte-arrays. A client can request the data to be sent as either ArrayBuffer or as a Blob. The server should send the data as pure binary data. Databases often uses Blob to describe binary objects as well, and in essence we are talking basically about byte-arrays.

if you have then Additional detail

You need to encapsulate the binary data as a BLOB object, then use URL.createObjectURL() to generate a local URL for it:

var blob = new Blob([arrayBufferWithPNG], {type: "image/png"}),
    url = URL.createObjectURL(blob),
    img = new Image();

img.onload = function() {
    URL.revokeObjectURL(this.src);     // clean-up memory
    document.body.appendChild(this);   // add image to DOM
}

img.src = url;                         // can now "stream" the bytes

Note that URL may be prefixed in webkit-browsers, so use:

var url = (URL || webkitURL).createObjectURL(...);

"Debug certificate expired" error in Eclipse Android plugins

On a Mac, open the Terminal (current user's directory should open), cd ".android" ("ls" to validate debug.keystore is there). Finally "rm debug.keystore" to remove the file.

How to search for a file in the CentOS command line

CentOS is Linux, so as in just about all other Unix/Linux systems, you have the find command. To search for files within the current directory:

find -name "filename"

You can also have wildcards inside the quotes, and not just a strict filename. You can also explicitly specify a directory to start searching from as the first argument to find:

find / -name "filename"

will look for "filename" or all the files that match the regex expression in between the quotes, starting from the root directory. You can also use single quotes instead of double quotes, but in most cases you don't need either one, so the above commands will work without any quotes as well. Also, for example, if you're searching for java files and you know they are somewhere in your /home/username, do:

find /home/username -name *.java

There are many more options to the find command and you should do a:

man find

to learn more about it.

One more thing: if you start searching from / and are not root or are not sudo running the command, you might get warnings that you don't have permission to read certain directories. To ignore/remove those, do:

find / -name 'filename' 2>/dev/null

That just redirects the stderr to /dev/null.

How to write console output to a txt file

To write console output to a txt file

public static void main(String[] args) {
    int i;
    List<String> ls = new ArrayList<String>();
    for (i = 1; i <= 100; i++) {
        String str = null;
        str = +i + ":-  HOW TO WRITE A CONSOLE OUTPUT IN A TEXT FILE";
        ls.add(str);
    }
    String listString = "";
    for (String s : ls) {
        listString += s + "\n";
    }
    FileWriter writer = null;
    try {
        writer = new FileWriter("final.txt");
        writer.write(listString);
        writer.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

If you want to generate the PDF rather then the text file, you use the dependency given below:

<dependency>
        <groupId>com.itextpdf</groupId>
        <artifactId>itextpdf</artifactId>
        <version>5.0.6</version>
</dependency>

To generate a PDF, use this code:

public static void main(String[] args) {
    int i;
    List<String> ls = new ArrayList<String>();
    for (i = 1; i <= 100; i++) {
        String str = null;
        str = +i + ":- HOW TO WRITE A CONSOLE OUTPUT IN A PDF";
        ls.add(str);
    }
    String listString = "";

    for (String s : ls) {
        listString += s + "\n";
    }
    Document document = new Document();
    try {
        PdfWriter writer1 = PdfWriter
                .getInstance(
                        document,
                        new FileOutputStream(
                                "final_pdf.pdf"));
        document.open();
        document.add(new Paragraph(listString));
        document.close();
        writer1.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (DocumentException e) {
        e.printStackTrace();
    }
}

How to scroll table's "tbody" independent of "thead"?

thead {
  position: fixed;
  height: 10px; /* This is whatever height you want */
}
  tbody {
  position: fixed;
  margin-top: 10px; /* This has to match the height of thead */
  height: 300px; /* This is whatever height you want */
}

What does "request for member '*******' in something not a structure or union" mean?

I have enumerated possibly all cases where this error may occur in code and its comments below. Please add to it, if you come across more cases.

#include<stdio.h>
#include<malloc.h>

typedef struct AStruct TypedefedStruct;

struct AStruct
{
    int member;
};

void main()
{
    /*  Case 1
        ============================================================================
        Use (->) operator to access structure member with structure pointer, instead
        of dot (.) operator. 
    */
    struct AStruct *aStructObjPtr = (struct AStruct *)malloc(sizeof(struct AStruct));
    //aStructObjPtr.member = 1;      //Error: request for member ‘member’ in something not 
                                      //a structure or union. 
                                      //It should be as below.
    aStructObjPtr->member = 1;
    printf("%d",aStructObjPtr->member); //1


    /*  Case 2
        ============================================================================
        We can use dot (.) operator with struct variable to access its members, but 
        not with with struct pointer. But we have to ensure we dont forget to wrap 
        pointer variable inside brackets.
    */
    //*aStructObjPtr.member = 2;     //Error, should be as below.
    (*aStructObjPtr).member = 2;
    printf("%d",(*aStructObjPtr).member); //2


    /* Case 3
       =============================================================================
       Use (->) operator to access structure member with typedefed structure pointer, 
       instead of dot (.) operator. 
    */
    TypedefedStruct *typedefStructObjPtr = (TypedefedStruct *)malloc(sizeof(TypedefedStruct));
    //typedefStructObjPtr.member=3;  //Error, should be as below.
    typedefStructObjPtr->member=3;
    printf("%d",typedefStructObjPtr->member);  //3


    /*  Case 4
        ============================================================================
        We can use dot (.) operator with struct variable to access its members, but 
        not with with struct pointer. But we have to ensure we dont forget to wrap 
        pointer variable inside brackets.
    */
    //*typedefStructObjPtr.member = 4;  //Error, should be as below.    
    (*typedefStructObjPtr).member=4;
    printf("%d",(*typedefStructObjPtr).member);  //4


    /* Case 5
       ============================================================================
       We have to be extra carefull when dealing with pointer to pointers to 
       ensure that we follow all above rules.
       We need to be double carefull while putting brackets around pointers.
    */

    //5.1. Access via struct_ptrptr and  ->
    struct AStruct **aStructObjPtrPtr = &aStructObjPtr;
    //*aStructObjPtrPtr->member = 5;  //Error, should be as below.
    (*aStructObjPtrPtr)->member = 5;
    printf("%d",(*aStructObjPtrPtr)->member); //5

    //5.2. Access via struct_ptrptr and .
    //**aStructObjPtrPtr.member = 6;  //Error, should be as below.
    (**aStructObjPtrPtr).member = 6;
    printf("%d",(**aStructObjPtrPtr).member); //6

    //5.3. Access via typedefed_strct_ptrptr and ->
    TypedefedStruct **typedefStructObjPtrPtr = &typedefStructObjPtr;
    //*typedefStructObjPtrPtr->member = 7;  //Error, should be as below.
    (*typedefStructObjPtrPtr)->member = 7;
    printf("%d",(*typedefStructObjPtrPtr)->member); //7

    //5.4. Access via typedefed_strct_ptrptr and .
    //**typedefStructObjPtrPtr->member = 8;  //Error, should be as below.
    (**typedefStructObjPtrPtr).member = 8;
    printf("%d",(**typedefStructObjPtrPtr).member); //8

    //5.5. All cases 5.1 to 5.4 will fail if you include incorrect number of *
    //     Below are examples of such usage of incorrect number *, correspnding
    //     to int values assigned to them

    //(aStructObjPtrPtr)->member = 5; //Error
    //(*aStructObjPtrPtr).member = 6; //Error 
    //(typedefStructObjPtrPtr)->member = 7; //Error 
    //(*typedefStructObjPtrPtr).member = 8; //Error
}

The underlying ideas are straight:

  • Use . with structure variable. (Cases 2 and 4)
  • Use -> with pointer to structure. (Cases 1 and 3)
  • If you reach structure variable or pointer to structure variable by following pointer, then wrap the pointer inside bracket: (*ptr). and (*ptr)-> vs *ptr. and *ptr-> (All cases except case 1)
  • If you are reaching by following pointers, ensure you have correctly reached pointer to struct or struct whichever is desired. (Case 5, especially 5.5)

How can we generate getters and setters in Visual Studio?

I don't have Visual Studio installed on my machine anymore (and I'm using Linux), but I do remember that there was an wizard hidden somewhere inside one of the menus that gave access to a class builder.

With this wizard, you could define all your classes' details, including methods and attributes. If I remember well, there was an option through which you could ask Visual Studio to create the setters and getters automatically for you.

I know it's quite vague, but check it out and you might find it.

Modify table: How to change 'Allow Nulls' attribute from not null to allow null

This is the approach to do this: -

  1. Check whether the table or column exists or not.
  2. If yes, then alter the column. e.g:-
IF EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.COLUMNS WHERE 
            TABLE_CATALOG = 'DBName' AND 
            TABLE_SCHEMA = 'SchemaName' AND
            TABLE_NAME = 'TableName' AND
            COLUMN_NAME = 'ColumnName')
BEGIN
    ALTER TABLE DBName.SchemaName.TableName ALTER COLUMN ColumnName [data type] NULL
END  

If you don't have any schema then delete the schema line because you don't need to give the default schema.

Server.MapPath - Physical path given, virtual path expected

var files = Directory.GetFiles(@"E:\ftproot\sales");

Removing elements from array Ruby

A simple solution I frequently use:

arr = ['remove me',3,4,2,45]

arr[1..-1]

=> [3,4,2,45]

HTML favicon won't show on google chrome

A common issue where the favicon will not show up when expected is cache, if your .htaccess for example reads: ExpiresByType image/x-icon "access plus 1 month"

Then simply add a random value to your favicon reference: <link rel="shortcut icon" href="https://example.com/favicon.ico?r=31241" type="image/x-icon" />

Works every time for me even with heavy caching.

Reading/parsing Excel (xls) files with Python

For xlsx I like the solution posted earlier as https://web.archive.org/web/20180216070531/https://stackoverflow.com/questions/4371163/reading-xlsx-files-using-python. I uses modules from the standard library only.

def xlsx(fname):
    import zipfile
    from xml.etree.ElementTree import iterparse
    z = zipfile.ZipFile(fname)
    strings = [el.text for e, el in iterparse(z.open('xl/sharedStrings.xml')) if el.tag.endswith('}t')]
    rows = []
    row = {}
    value = ''
    for e, el in iterparse(z.open('xl/worksheets/sheet1.xml')):
        if el.tag.endswith('}v'):  # Example: <v>84</v>                            
            value = el.text
        if el.tag.endswith('}c'):  # Example: <c r="A3" t="s"><v>84</v></c>                                 
            if el.attrib.get('t') == 's':
                value = strings[int(value)]
            letter = el.attrib['r']  # Example: AZ22                         
            while letter[-1].isdigit():
                letter = letter[:-1]
            row[letter] = value
            value = ''
        if el.tag.endswith('}row'):
            rows.append(row)
            row = {}
    return rows

Improvements added are fetching content by sheet name, using re to get the column and checking if sharedstrings are used.

def xlsx(fname,sheet):
    import zipfile
    from xml.etree.ElementTree import iterparse
    import re
    z = zipfile.ZipFile(fname)
    if 'xl/sharedStrings.xml' in z.namelist():
        # Get shared strings
        strings = [element.text for event, element
                   in iterparse(z.open('xl/sharedStrings.xml')) 
                   if element.tag.endswith('}t')]
    sheetdict = { element.attrib['name']:element.attrib['sheetId'] for event,element in iterparse(z.open('xl/workbook.xml'))
                                      if element.tag.endswith('}sheet') }
    rows = []
    row = {}
    value = ''

    if sheet in sheets:
    sheetfile = 'xl/worksheets/sheet'+sheets[sheet]+'.xml'
    #print(sheet,sheetfile)
    for event, element in iterparse(z.open(sheetfile)):
        # get value or index to shared strings
        if element.tag.endswith('}v') or element.tag.endswith('}t'):
            value = element.text
        # If value is a shared string, use value as an index
        if element.tag.endswith('}c'):
            if element.attrib.get('t') == 's':
                value = strings[int(value)]
            # split the row/col information so that the row leter(s) can be separate
            letter = re.sub('\d','',element.attrib['r'])
            row[letter] = value
            value = ''
        if element.tag.endswith('}row'):
            rows.append(row)
            row = {}

    return rows

Persistent invalid graphics state error when using ggplot2

try to get out grafics with x11() or win.graph() and solve this trouble.

How to install OpenJDK 11 on Windows?

  1. Extract the zip file into a folder, e.g. C:\Program Files\Java\ and it will create a jdk-11 folder (where the bin folder is a direct sub-folder). You may need Administrator privileges to extract the zip file to this location.

  2. Set a PATH:

    • Select Control Panel and then System.
    • Click Advanced and then Environment Variables.
    • Add the location of the bin folder of the JDK installation to the PATH variable in System Variables.
    • The following is a typical value for the PATH variable: C:\WINDOWS\system32;C:\WINDOWS;"C:\Program Files\Java\jdk-11\bin"
  3. Set JAVA_HOME:

    • Under System Variables, click New.
    • Enter the variable name as JAVA_HOME.
    • Enter the variable value as the installation path of the JDK (without the bin sub-folder).
    • Click OK.
    • Click Apply Changes.
  4. Configure the JDK in your IDE (e.g. IntelliJ or Eclipse).

You are set.

To see if it worked, open up the Command Prompt and type java -version and see if it prints your newly installed JDK.

If you want to uninstall - just undo the above steps.

Note: You can also point JAVA_HOME to the folder of your JDK installations and then set the PATH variable to %JAVA_HOME%\bin. So when you want to change the JDK you change only the JAVA_HOME variable and leave PATH as it is.

How to declare a variable in SQL Server and use it in the same Stored Procedure

What's going wrong with what you have? What error do you get, or what result do or don't you get that doesn't match your expectations?

I can see the following issues with that SP, which may or may not relate to your problem:

  • You have an extraneous ) after @BrandName in your SELECT (at the end)
  • You're not setting @CategoryID or @BrandName to anything anywhere (they're local variables, but you don't assign values to them)

Edit Responding to your comment: The error is telling you that you haven't declared any parameters for the SP (and you haven't), but you called it with parameters. Based on your reply about @CategoryID, I'm guessing you wanted it to be a parameter rather than a local variable. Try this:

CREATE PROCEDURE AddBrand
   @BrandName nvarchar(50),
   @CategoryID int
AS
BEGIN
   DECLARE @BrandID int

   SELECT @BrandID = BrandID FROM tblBrand WHERE BrandName = @BrandName

   INSERT INTO tblBrandinCategory (CategoryID, BrandID) VALUES (@CategoryID, @BrandID)
END

You would then call this like this:

EXEC AddBrand 'Gucci', 23

...assuming the brand name was 'Gucci' and category ID was 23.

Making a mocked method return an argument that was passed to it

This is a bit old, but I came here because I had the same issue. I'm using JUnit but this time in a Kotlin app with mockk. I'm posting a sample here for reference and comparison with the Java counterpart:

@Test
fun demo() {
  // mock a sample function
  val aMock: (String) -> (String) = mockk()

  // make it return the same as the argument on every invocation
  every {
    aMock.invoke(any())
  } answers {
    firstArg()
  }

  // test it
  assertEquals("senko", aMock.invoke("senko"))
  assertEquals("senko1", aMock.invoke("senko1"))
  assertNotEquals("not a senko", aMock.invoke("senko"))
}

Linq to Sql: Multiple left outer joins

This may be cleaner (you dont need all the into statements):

var query = 
    from order in dc.Orders
    from vendor 
    in dc.Vendors
        .Where(v => v.Id == order.VendorId)
        .DefaultIfEmpty()
    from status 
    in dc.Status
        .Where(s => s.Id == order.StatusId)
        .DefaultIfEmpty()
    select new { Order = order, Vendor = vendor, Status = status } 
    //Vendor and Status properties will be null if the left join is null

Here is another left join example

var results = 
    from expense in expenseDataContext.ExpenseDtos
    where expense.Id == expenseId //some expense id that was passed in
    from category 
    // left join on categories table if exists
    in expenseDataContext.CategoryDtos
                         .Where(c => c.Id == expense.CategoryId)
                         .DefaultIfEmpty() 
    // left join on expense type table if exists
    from expenseType 
    in expenseDataContext.ExpenseTypeDtos
                         .Where(e => e.Id == expense.ExpenseTypeId)
                         .DefaultIfEmpty()
    // left join on currency table if exists
    from currency 
    in expenseDataContext.CurrencyDtos
                         .Where(c => c.CurrencyID == expense.FKCurrencyID)
                         .DefaultIfEmpty() 
    select new 
    { 
        Expense = expense,
        // category will be null if join doesn't exist
        Category = category,
        // expensetype will be null if join doesn't exist
        ExpenseType = expenseType,
        // currency will be null if join doesn't exist
        Currency = currency  
    }

Iterating Through a Dictionary in Swift

Here is an alternative for that experiment (Swift 3.0). This tells you exactly which kind of number was the largest.

let interestingNumbers = [
"Prime": [2, 3, 5, 7, 11, 13],
"Fibonacci": [1, 1, 2, 3, 5, 8],
"Square": [1, 4, 9, 16, 25],
]

var largest = 0
var whichKind: String? = nil

for (kind, numbers) in interestingNumbers {
    for number in numbers {
    if number > largest {
        whichKind = kind
        largest = number
    }
  }
}

print(whichKind)
print(largest)

OUTPUT:
Optional("Square")
25

How can I show an element that has display: none in a CSS rule?

I can see that you want to write you own short javascript for this, but have you considered to use Frameworks for HTML manipulation instead? jQuery is my prefered tool for such a task, eventhough its an overkill for your current question as it has SO many extra functionalities.

Have a look at jQuery here

How to allow only integers in a textbox?

Try this:

Note:This is using Ajax Toolkit

First add Ajax Script Manager and use the below Code

<asp:FilteredTextBoxExtender ID="TextBox1_FilteredTextBoxExtender" runat="server"
Enabled="True" TargetControlID="TextBox1" FilterType="Numbers">
</asp:FilteredTextBoxExtender>

Running a shell script through Cygwin on Windows

If you have access to the Notepad++ editor on Windows there is a feature that allows you to easily get around this problem:

  1. Open the file that's giving the error in Notepad++.
  2. Go under the "Edit" Menu and choose "EOL Conversion"
  3. There is an option there for "UNIX/OSX Format." Choose that option.
  4. Re-save the file.

I did this and it solved my problems.

Hope this helps!

Read more at http://danieladeniji.wordpress.com/2013/03/07/microsoft-windows-cygwin-error-r-command-not-found/

How to style icon color, size, and shadow of Font Awesome Icons

For Size : fa-lg, fa-2x, fa-3x, fa-4x, fa-5x.

For Color : <i class="fa fa-link fa-lg" aria-hidden="true"style="color:indianred"></i>

For Shadow : .fa-linkedin-square{text-shadow: 3px 6px #272634;}

How can I get a value from a map?

map.at("key") throws exception if missing key

If k does not match the key of any element in the container, the function throws an out_of_range exception.

http://www.cplusplus.com/reference/map/map/at/

estimating of testing effort as a percentage of development time

Are you talking about automated unit/integration tests or manual tests?

For the former, my rule of thumb (based on measurements) is 40-50% added to development time i.e. if developing a use case takes 10 days (before an QA and serious bugfixing happens), writing good tests takes another 4 to 5 days - though this should best happen before and during development, not afterwards.

System has not been booted with systemd as init system (PID 1). Can't operate

I had this problem running WSL 2

the solution was the command

 $ sudo dockerd

if after that you still have a problem with permission, run the command:

 $ sudo usermod -aG docker your-user

expected assignment or function call: no-unused-expressions ReactJS

In my case, I got the error on the setState line:

increment(){
  this.setState(state => {
    count: state.count + 1
  });
}

I changed it to this, now it works

increment(){
  this.setState(state => {
    const count = state.count + 1

    return {
      count
    };
  });
}

How to upload (FTP) files to server in a bash script?

if you want to use it inside a 'for' to copy the last generated files for a every-day bacakup...

j=0  
var="`find /backup/path/ -name 'something*' -type f -mtime -1`"  
#we have in $var some files with last day change date

for i in $var  
  do  
  j=$(( $j + 1 ))  
  dirname="`dirname $i`"  
  filename="`basename $i`"  
  /usr/bin/ftp -in >> /tmp/ftp.good 2>> /tmp/ftp.bad << EOF  
    open 123.456.789.012  
    user user_name passwd  
    bin  
    lcd $dirname  
    put $filename  
    quit  
  EOF      #end of ftp  
done       #end of for iteration

SQL Server date format yyyymmdd

You can do as follows:

Select Format(test.Time, 'yyyyMMdd')
From TableTest test

How to disable compiler optimizations in gcc?

The gcc option -O enables different levels of optimization. Use -O0 to disable them and use -S to output assembly. -O3 is the highest level of optimization.

Starting with gcc 4.8 the optimization level -Og is available. It enables optimizations that do not interfere with debugging and is the recommended default for the standard edit-compile-debug cycle.

To change the dialect of the assembly to either intel or att use -masm=intel or -masm=att.

You can also enable certain optimizations manually with -fname.

Have a look at the gcc manual for much more.

From an array of objects, extract value of a property as array

Easily extracting multiple properties from array of objects:

let arrayOfObjects = [
  {id:1, name:'one', desc:'something'},
  {id:2, name:'two', desc:'something else'}
];

//below will extract just the id and name
let result = arrayOfObjects.map(({id, name}) => ({id, name}));

result will be [{id:1, name:'one'},{id:2, name:'two'}]

Add or remove properties as needed in the map function

PHP: Convert any string to UTF-8 without knowing the original character set, or at least try

There is no way to identify the charset of a string that is completely accurate. There are ways to try to guess the charset. One of these ways, and probably/currently the best in PHP, is mb_detect_encoding(). This will scan your string and look for occurrences of stuff unique to certain charsets. Depending on your string, there may not be such distinguishable occurrences.

Take the ISO-8859-1 charset vs ISO-8859-15 ( http://en.wikipedia.org/wiki/ISO/IEC_8859-15#Changes_from_ISO-8859-1 )

There's only a handful of different characters, and to make it worse, they're represented by the same bytes. There is no way to detect, being given a string without knowing it's encoding, whether byte 0xA4 is supposed to signify ¤ or € in your string, so there is no way to know it's exact charset.

(Note: you could add a human factor, or an even more advanced scanning technique (e.g. what Oroboros102 suggests), to try to figure out based upon the surrounding context, if the character should be ¤ or €, though this seems like a bridge too far)

There are more distinguishable differences between e.g. UTF-8 and ISO-8859-1, so it's still worth trying to figure it out when you're unsure, though you can and should never rely on it being correct.

Interesting read: http://kore-nordmann.de/blog/php_charset_encoding_FAQ.html#how-do-i-determine-the-charset-encoding-of-a-string

There are other ways of ensuring the correct charset though. Concerning forms, try to enforce UTF-8 as much as possible (check out snowman to make sure yout submission will be UTF-8 in every browser: http://intertwingly.net/blog/2010/07/29/Rails-and-Snowmen ) That being done, at least you're can be sure that every text submitted through your forms is utf_8. Concerning uploaded files, try running the unix 'file -i' command on it through e.g. exec() (if possible on your server) to aid the detection (using the document's BOM.) Concerning scraping data, you could read the HTTP headers, that usually specify the charset. When parsing XML files, see if the XML meta-data contain a charset definition.

Rather than trying to automagically guess the charset, you should first try to ensure a certain charset yourself where possible, or trying to grab a definition from the source you're getting it from (if applicable) before resorting to detection.

replace String with another in java

The replace method is what you're looking for.

For example:

String replacedString = someString.replace("HelloBrother", "Brother");

What is the SSIS package and what does it do?

For Latest Info About SSIS > https://docs.microsoft.com/en-us/sql/integration-services/sql-server-integration-services

From the above referenced site:

Microsoft Integration Services is a platform for building enterprise-level data integration and data transformations solutions. Use Integration Services to solve complex business problems by copying or downloading files, loading data warehouses, cleansing and mining data, and managing SQL Server objects and data.

Integration Services can extract and transform data from a wide variety of sources such as XML data files, flat files, and relational data sources, and then load the data into one or more destinations.

Integration Services includes a rich set of built-in tasks and transformations, graphical tools for building packages, and the Integration Services Catalog database, where you store, run, and manage packages.

You can use the graphical Integration Services tools to create solutions without writing a single line of code. You can also program the extensive Integration Services object model to create packages programmatically and code custom tasks and other package objects.

Getting Started with SSIS - http://msdn.microsoft.com/en-us/sqlserver/bb671393.aspx

If you are Integration Services Information Worker - http://msdn.microsoft.com/en-us/library/ms141667.aspx

If you are Integration Services Administrator - http://msdn.microsoft.com/en-us/library/ms137815.aspx

If you are Integration Services Developer - http://msdn.microsoft.com/en-us/library/ms137709.aspx

If you are Integration Services Architect - http://msdn.microsoft.com/en-us/library/ms142161.aspx

Overview of SSIS - http://msdn.microsoft.com/en-us/library/ms141263.aspx

Integration Services How-to Topics - http://msdn.microsoft.com/en-us/library/ms141767.aspx

What is a callback?

A callback is a function pointer that you pass in to another function. The function you are calling will 'callback' (execute) the other function when it has completed.

Check out this link.

Is there a difference between `continue` and `pass` in a for loop in python?

There is a difference between them,
continue skips the loop's current iteration and executes the next iteration.
pass does nothing. It’s an empty statement placeholder.
I would rather give you an example, which will clarify this more better.

>>> for element in some_list:
...     if element == 1:
...         print "Pass executed"
...         pass
...     print element
... 
0
Pass executed
1
2

>>> for element in some_list:
...     if element == 1:
...         print "Continue executed"
...         continue
...     print element
... 
0
Continue executed
2

mongodb service is not starting up

Nianliang's solution turned out so useful from my Vagrant ubunuto, thart I ended up adding these 2 commands to my /etc/init.d/mongodb file:

.
.
.    
start|stop|restart)
        rm /var/lib/mongodb/mongod.lock
        mongod --repair
.
.
.

Why can't I enter a string in Scanner(System.in), when calling nextLine()-method?

Scanner's buffer full when we take a input string through scan.nextLine(); so it skips the input next time . So solution is that we can create a new object of Scanner , the name of the object can be same as previous object......

How to make a local variable (inside a function) global

You could use module scope. Say you have a module called utils:

f_value = 'foo'

def f():
    return f_value

f_value is a module attribute that can be modified by any other module that imports it. As modules are singletons, any change to utils from one module will be accessible to all other modules that have it imported:

>> import utils
>> utils.f()
'foo'
>> utils.f_value = 'bar'
>> utils.f()
'bar'

Note that you can import the function by name:

>> import utils
>> from utils import f
>> utils.f_value = 'bar'
>> f()
'bar'

But not the attribute:

>> from utils import f, f_value
>> f_value = 'bar'
>> f()
'foo'

This is because you're labeling the object referenced by the module attribute as f_value in the local scope, but then rebinding it to the string bar, while the function f is still referring to the module attribute.

pass **kwargs argument to another function with **kwargs

For #2 args will be only a formal parameter with dict value, but not a keyword type parameter.

If you want to pass a keyword type parameter into a keyword argument You need to specific ** before your dictionary, which means **args

check this out for more detail on using **kw

http://www.saltycrane.com/blog/2008/01/how-to-use-args-and-kwargs-in-python/

Use the auto keyword in C++ STL

The auto keyword is simply asking the compiler to deduce the type of the variable from the initialization.

Even a pre-C++0x compiler knows what the type of an (initialization) expression is, and more often than not, you can see that type in error messages.

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

int main()
{
    vector<int>s;
    s.push_back(11);
    s.push_back(22);
    s.push_back(33);
    s.push_back(55);
    for (int it=s.begin();it!=s.end();it++){
        cout<<*it<<endl;
    }
}

Line 12: error: cannot convert '__gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<int*, __gnu_norm::vector<int, std::allocator<int> > >, __gnu_debug_def::vector<int, std::allocator<int> > >' to 'int' in initialization

The auto keyword simply allows you to take advantage of this knowledge - if you (compiler) know the right type, just choose for me!

Converting a JS object to an array using jQuery

Fiddle Demo

Extension to answer of bjornd .

var myObj = {
    1: [1, [2], 3],
    2: [4, 5, [6]]
}, count = 0,
    i;
//count the JavaScript object length supporting IE < 9 also
for (i in myObj) {
    if (myObj.hasOwnProperty(i)) {
        count++;
    }
}
//count = Object.keys(myObj).length;// but not support IE < 9
myObj.length = count + 1; //max index + 1
myArr = Array.prototype.slice.apply(myObj);
console.log(myArr);


Reference

Array.prototype.slice()

Function.prototype.apply()

Object.prototype.hasOwnProperty()

Object.keys()

How do I make a new line in swift

You can use the following code;

var example: String = "Hello World \r\n This is a new line"

How to rename a directory/folder on GitHub website?

Go to that directory/folder and then click on the setting. In the section of "Repository name" simply rename it.

round() for float in C++

You could round to n digits precision with:

double round( double x )
{
const double sd = 1000; //for accuracy to 3 decimal places
return int(x*sd + (x<0? -0.5 : 0.5))/sd;
}

How do I check if a string contains a specific word?

Maybe you could use something like this:

<?php
    findWord('Test all OK');

    function findWord($text) {
        if (strstr($text, 'ok')) {
            echo 'Found a word';
        }
        else
        {
            echo 'Did not find a word';
        }
    }
?>

How to delete Certain Characters in a excel 2010 cell

Replace [ with nothing, then ] with nothing.

How to convert string to integer in UNIX

The standard solution:

 expr $d1 - $d2

You can also do:

echo $(( d1 - d2 ))

but beware that this will treat 07 as an octal number! (so 07 is the same as 7, but 010 is different than 10).

Java constructor/method with optional parameters?

Java doesn't have the concept of optional parameters with default values either in constructors or in methods. You're basically stuck with overloading. However, you chain constructors easily so you don't need to repeat the code:

public Foo(int param1, int param2)
{
    this.param1 = param1;
    this.param2 = param2;
}

public Foo(int param1)
{
    this(param1, 2);
}

How to set width of a div in percent in JavaScript?

The question is what do you want the div's height/width to be a percent of?

By default, if you assign a percentage value to a height/width it will be relative to it's direct parent dimensions. If the parent doesn't have a defined height, then it won't work.

So simply, remember to set the height of the parent, then a percentage height will work via the css attribute:

obj.style.width = '50%';

How to remove all MySQL tables from the command-line without DROP database permissions?

You can drop the database and then recreate it with the below:-

mysql> drop database [database name];
mysql> create database [database name];

Delete from a table based on date

delete from YOUR_TABLE where your_date_column < '2009-01-01';

This will delete rows from YOUR_TABLE where the date in your_date_column is older than January 1st, 2009. i.e. a date with 2008-12-31 would be deleted.

Reset IntelliJ UI to Default

Recent Versions

Window -> Restore Default Layout

(Thanks to Seven4X's answer)

Older Versions

You can simply delete the whole configuration folder ${user.home}/.IntelliJIdea60/config while IntelliJ IDEA is not running. Next time it restarts, everything is restored from the default settings.

It depends on the OS:

https://intellij-support.jetbrains.com/entries/23358108

How to get my activity context?

You can create a constructor using parameter Context of class A then you can use this context.

Context c;

A(Context context){ this.c=context }

From B activity you create a object of class A using this constructor and passing getApplicationContext().

Populating a database in a Laravel migration file

I know this is an old post but since it comes up in a google search I thought I'd share some knowledge here. @erin-geyer pointed out that mixing migrations and seeders can create headaches and @justamartin countered that sometimes you want/need data to be populated as part of your deployment.

I'd go one step further and say that sometimes it is desirable to be able to roll out data changes consistently so that you can for example deploy to staging, see that all is well, and then deploy to production with confidence of the same results (and not have to remember to run some manual step).

However, there is still value in separating out the seed and the migration as those are two related but distinct concerns. Our team has compromised by creating migrations which call seeders. This looks like:

public function up()
{
    Artisan::call( 'db:seed', [
        '--class' => 'SomeSeeder',
        '--force' => true ]
    );
}

This allows you to execute a seed one time just like a migration. You can also implement logic that prevents or augments behavior. For example:

public function up()
{
    if ( SomeModel::count() < 10 )
    {
        Artisan::call( 'db:seed', [
            '--class' => 'SomeSeeder',
            '--force' => true ]
        );
    }
}

This would obviously conditionally execute your seeder if there are less than 10 SomeModels. This is useful if you want to include the seeder as a standard seeder that executed when you call artisan db:seed as well as when you migrate so that you don't "double up". You may also create a reverse seeder so that rollbacks works as expected, e.g.

public function down()
{
    Artisan::call( 'db:seed', [
        '--class' => 'ReverseSomeSeeder',
        '--force' => true ]
    );
}

The second parameter --force is required to enable to seeder to run in a production environment.

Maven error in eclipse (pom.xml) : Failure to transfer org.apache.maven.plugins:maven-surefire-plugin:pom:2.12.4

In my case it was a failed import to eclipse. I had to delete the project from eclipse (without deleting form the filesystem of course) and reimport it. After that the error was gone immediately.

JQuery post JSON object to a server

To send json to the server, you first have to create json

function sendData() {
    $.ajax({
        url: '/helloworld',
        type: 'POST',
        contentType: 'application/json',
        data: JSON.stringify({
            name:"Bob",
            ...
        }),
        dataType: 'json'
    });
}

This is how you would structure the ajax request to send the json as a post var.

function sendData() {
    $.ajax({
        url: '/helloworld',
        type: 'POST',
        data: { json: JSON.stringify({
            name:"Bob",
            ...
        })},
        dataType: 'json'
    });
}

The json will now be in the json post var.

What is this: [Ljava.lang.Object;?

If you are here because of the Liquibase error saying:

Caused By: Precondition Error
...
Can't detect type of array [Ljava.lang.Short

and you are using

not {
  indexExists()
}

precondition multiple times, then you are facing an old bug: https://liquibase.jira.com/browse/CORE-1342

We can try to execute an above check using bare sqlCheck(Postgres):

SELECT COUNT(i.relname)
FROM
    pg_class t,
    pg_class i,
    pg_index ix
WHERE
    t.oid = ix.indrelid
    and i.oid = ix.indexrelid
    and t.relkind = 'r'
    and t.relname = 'tableName'
    and i.relname = 'indexName';

where tableName - is an index table name and indexName - is an index name

Selenium WebDriver: I want to overwrite value in field instead of appending to it with sendKeys using Java

This is something easy to do and it worked for me:

//Create a Javascript executor

JavascriptExecutor jst= (JavascriptExecutor) driver;
jst.executeScript("arguments[1].value = arguments[0]; ", 55, driver.findElement(By.id("id")));

55 = value assigned

What are the differences between NP, NP-Complete and NP-Hard?

In addition to the other great answers, here is the typical schema people use to show the difference between NP, NP-Complete, and NP-Hard:

enter image description here

Copy files to network computers on windows command line

check Robocopy:

ROBOCOPY \\server-source\c$\VMExports\ C:\VMExports\ /E /COPY:DAT

make sure you check what robocopy parameter you want. this is just an example. type robocopy /? in a comandline/powershell on your windows system.

The ORDER BY clause is invalid in views, inline functions, derived tables, subqueries, and common table expressions

ORDER BY column OFFSET 0 ROWS

Surprisingly makes it work, what a strange feature.

A bigger example with a CTE as a way to temporarily "store" a long query to re-order it later:

;WITH cte AS (
    SELECT .....long select statement here....
)

SELECT * FROM 
(
    SELECT * FROM 
    ( -- necessary to nest selects for union to work with where & order clauses
        SELECT * FROM cte WHERE cte.MainCol= 1 ORDER BY cte.ColX asc OFFSET 0 ROWS 
    ) first
    UNION ALL
    SELECT * FROM 
    (  
        SELECT * FROM cte WHERE cte.MainCol = 0 ORDER BY cte.ColY desc OFFSET 0 ROWS 
    ) last
) as unionized
ORDER BY unionized.MainCol desc -- all rows ordered by this one
OFFSET @pPageSize * @pPageOffset ROWS -- params from stored procedure for pagination, not relevant to example
FETCH FIRST @pPageSize ROWS ONLY -- params from stored procedure for pagination, not relevant to example

So we get all results ordered by MainCol

But the results with MainCol = 1 get ordered by ColX

And the results with MainCol = 0 get ordered by ColY

Linux find and grep command together

Now that the question is clearer, you can just do this in one

grep -R --include "*bills*" "put" .

With relevant flags

   -R, -r, --recursive
          Read  all  files  under  each  directory,  recursively;  this is
          equivalent to the -d recurse option.
   --include=GLOB
          Search only files whose base name matches GLOB  (using  wildcard
          matching as described under --exclude).

gnuplot : plotting data from multiple input files in a single graph

replot

This is another way to get multiple plots at once:

plot file1.data
replot file2.data

How do I test if a recordSet is empty? isNull?

A simple way is to write it:

Dim rs As Object
Set rs = Me.Recordset.Clone
If Me.Recordset.RecordCount = 0 then 'checks for number of records
   msgbox "There is no records" 
End if

Permanently adding a file path to sys.path in Python

This way worked for me:

adding the path that you like:

export PYTHONPATH=$PYTHONPATH:/path/you/want/to/add

checking: you can run 'export' cmd and check the output or you can check it using this cmd:

python -c "import sys; print(sys.path)"

How to initialise a string from NSData in Swift

This is how you should initialize the NSString:

Swift 2.X or older

let datastring = NSString(data: fooData, encoding: NSUTF8StringEncoding)

Swift 3 or newer:

let datastring = NSString(data: fooData, encoding: String.Encoding.utf8.rawValue)

This doc explains the syntax.

How can I make a weak protocol reference in 'pure' Swift (without @objc)

AnyObject is the official way to use a weak reference in Swift.

class MyClass {
    weak var delegate: MyClassDelegate?
}

protocol MyClassDelegate: AnyObject {
}

From Apple:

To prevent strong reference cycles, delegates should be declared as weak references. For more information about weak references, see Strong Reference Cycles Between Class Instances. Marking the protocol as class-only will later allow you to declare that the delegate must use a weak reference. You mark a protocol as being class-only by inheriting from AnyObject, as discussed in Class-Only Protocols.

https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/Protocols.html#//apple_ref/doc/uid/TP40014097-CH25-ID276

Best approach to real time http streaming to HTML5 video client

This is a very common misconception. There is no live HTML5 video support (except for HLS on iOS and Mac Safari). You may be able to 'hack' it using a webm container, but I would not expect that to be universally supported. What you are looking for is included in the Media Source Extensions, where you can feed the fragments to the browser one at a time. but you will need to write some client side javascript.

Creating a batch file, for simple javac and java command execution

Create a plain text file (using notepad) and type the exact line you would use to run your Java file with the command prompt. Then change the extension to .bat and you're done.

Double clicking on this file would run your java program.

I reccommend one file for javac, one for java so you can troubleshoot if anything is wrong.

  • Make sure java is in your path, too.. IE typing java in a Dos windows when in your java workspace should bring up the java version message. If java is not in your path the batch file won't work unless you use absolut path to the java binary.

How do I import a .dmp file into Oracle?

i got solution what you are getting as per imp help=y it is mentioned that imp is only valid for TRANSPORT_TABLESPACE as below:

Keyword  Description (Default)       Keyword      Description (Default)
--------------------------------------------------------------------------
USERID   username/password           FULL         import entire file (N)
BUFFER   size of data buffer         FROMUSER     list of owner usernames
FILE     input files (EXPDAT.DMP)    TOUSER       list of usernames
SHOW     just list file contents (N) TABLES       list of table names
IGNORE   ignore create errors (N)    RECORDLENGTH length of IO record
GRANTS   import grants (Y)           INCTYPE      incremental import type
INDEXES  import indexes (Y)          COMMIT       commit array insert (N)
ROWS     import data rows (Y)        PARFILE      parameter filename
LOG      log file of screen output   CONSTRAINTS  import constraints (Y)
DESTROY                overwrite tablespace data file (N)
INDEXFILE              write table/index info to specified file
SKIP_UNUSABLE_INDEXES  skip maintenance of unusable indexes (N)
FEEDBACK               display progress every x rows(0)
TOID_NOVALIDATE        skip validation of specified type ids
FILESIZE               maximum size of each dump file
STATISTICS             import precomputed statistics (always)
RESUMABLE              suspend when a space related error is encountered(N)
RESUMABLE_NAME         text string used to identify resumable statement
RESUMABLE_TIMEOUT      wait time for RESUMABLE
COMPILE                compile procedures, packages, and functions (Y)
STREAMS_CONFIGURATION  import streams general metadata (Y)
STREAMS_INSTANTIATION  import streams instantiation metadata (N)
DATA_ONLY              import only data (N)

The following keywords only apply to transportable tablespaces
TRANSPORT_TABLESPACE import transportable tablespace metadata (N)
TABLESPACES tablespaces to be transported into database
DATAFILES datafiles to be transported into database
TTS_OWNERS users that own data in the transportable tablespace set

So, Please create table space for your user:

CREATE TABLESPACE <tablespace name> DATAFILE <path to save, example: 'C:\ORACLEXE\APP\ORACLE\ORADATA\XE\ABC.dbf'> SIZE 100M AUTOEXTEND ON NEXT 100M MAXSIZE 10G EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M;

Simple 'if' or logic statement in Python

If key isn't an int or float but a string, you need to convert it to an int first by doing

key = int(key)

or to a float by doing

key = float(key)

Otherwise, what you have in your question should work, but

if (key < 1) or (key > 34):

or

if not (1 <= key <= 34):

would be a bit clearer.

Getting Serial Port Information

I combined previous answers and used structure of Win32_PnPEntity class which can be found found here. Got solution like this:

using System.Management;
public static void Main()
{
     GetPortInformation();
}

public string GetPortInformation()
    {
        ManagementClass processClass = new ManagementClass("Win32_PnPEntity");
        ManagementObjectCollection Ports = processClass.GetInstances();           
        foreach (ManagementObject property in Ports)
        {
            var name = property.GetPropertyValue("Name");               
            if (name != null && name.ToString().Contains("USB") && name.ToString().Contains("COM"))
            {
                var portInfo = new SerialPortInfo(property);
                //Thats all information i got from port.
                //Do whatever you want with this information
            }
        }
        return string.Empty;
    }

SerialPortInfo class:

public class SerialPortInfo
{
    public SerialPortInfo(ManagementObject property)
    {
        this.Availability = property.GetPropertyValue("Availability") as int? ?? 0;
        this.Caption = property.GetPropertyValue("Caption") as string ?? string.Empty;
        this.ClassGuid = property.GetPropertyValue("ClassGuid") as string ?? string.Empty;
        this.CompatibleID = property.GetPropertyValue("CompatibleID") as string[] ?? new string[] {};
        this.ConfigManagerErrorCode = property.GetPropertyValue("ConfigManagerErrorCode") as int? ?? 0;
        this.ConfigManagerUserConfig = property.GetPropertyValue("ConfigManagerUserConfig") as bool? ?? false;
        this.CreationClassName = property.GetPropertyValue("CreationClassName") as string ?? string.Empty;
        this.Description = property.GetPropertyValue("Description") as string ?? string.Empty;
        this.DeviceID = property.GetPropertyValue("DeviceID") as string ?? string.Empty;
        this.ErrorCleared = property.GetPropertyValue("ErrorCleared") as bool? ?? false;
        this.ErrorDescription = property.GetPropertyValue("ErrorDescription") as string ?? string.Empty;
        this.HardwareID = property.GetPropertyValue("HardwareID") as string[] ?? new string[] { };
        this.InstallDate = property.GetPropertyValue("InstallDate") as DateTime? ?? DateTime.MinValue;
        this.LastErrorCode = property.GetPropertyValue("LastErrorCode") as int? ?? 0;
        this.Manufacturer = property.GetPropertyValue("Manufacturer") as string ?? string.Empty;
        this.Name = property.GetPropertyValue("Name") as string ?? string.Empty;
        this.PNPClass = property.GetPropertyValue("PNPClass") as string ?? string.Empty;
        this.PNPDeviceID = property.GetPropertyValue("PNPDeviceID") as string ?? string.Empty;
        this.PowerManagementCapabilities = property.GetPropertyValue("PowerManagementCapabilities") as int[] ?? new int[] { };
        this.PowerManagementSupported = property.GetPropertyValue("PowerManagementSupported") as bool? ?? false;
        this.Present = property.GetPropertyValue("Present") as bool? ?? false;
        this.Service = property.GetPropertyValue("Service") as string ?? string.Empty;
        this.Status = property.GetPropertyValue("Status") as string ?? string.Empty;
        this.StatusInfo = property.GetPropertyValue("StatusInfo") as int? ?? 0;
        this.SystemCreationClassName = property.GetPropertyValue("SystemCreationClassName") as string ?? string.Empty;
        this.SystemName = property.GetPropertyValue("SystemName") as string ?? string.Empty;
    }

    int Availability;
    string Caption;
    string ClassGuid;
    string[] CompatibleID;
    int ConfigManagerErrorCode;
    bool ConfigManagerUserConfig;
    string CreationClassName;
    string Description;
    string DeviceID;
    bool ErrorCleared;
    string ErrorDescription;
    string[] HardwareID;
    DateTime InstallDate;
    int LastErrorCode;
    string Manufacturer;
    string Name;
    string PNPClass;
    string PNPDeviceID;
    int[] PowerManagementCapabilities;
    bool PowerManagementSupported;
    bool Present;
    string Service;
    string Status;
    int StatusInfo;
    string SystemCreationClassName;
    string SystemName;       

}

Permutations in JavaScript?

My first contribution to the site. Also, according to the tests that I have done, this code runs faster than all the other methods mentioned here before this date, of course it is minimal if there are few values, but the time increases exponentially when adding too many.

_x000D_
_x000D_
var result = permutations([1,2,3,4]);

var output = window.document.getElementById('output');
output.innerHTML = JSON.stringify(result);

function permutations(arr) {
    var finalArr = [];
    function iterator(arrayTaken, tree) {
        var temp;
        for (var i = 0; i < tree; i++) {
            temp = arrayTaken.slice();
            temp.splice(tree - 1 - i, 0, temp.splice(tree - 1, 1)[0]);
            if (tree >= arr.length) {
                finalArr.push(temp);
            } else {
                iterator(temp, tree + 1);
            }
        }
    }
    iterator(arr, 1);
    return finalArr;
};
_x000D_
<div id="output"></div>
_x000D_
_x000D_
_x000D_

CSS :selected pseudo class similar to :checked, but for <select> elements

This worked for me :

select option {
   color: black;
}
select:not(:checked) {
   color: gray;
}

Controlling a USB power supply (on/off) with Linux

USB 5v power is always on (even when the computer is turned off, on some computers and on some ports.) You will probably need to program an Arduino with some sort of switch, and control it via Serial library from USB plugged in to the computer.

In other words, a combination of this switch tutorial and this tutorial on communicating via Serial libary to Arduino plugged in via USB.

How to get method parameter names?

Take a look at the inspect module - this will do the inspection of the various code object properties for you.

>>> inspect.getfullargspec(a_method)
(['arg1', 'arg2'], None, None, None)

The other results are the name of the *args and **kwargs variables, and the defaults provided. ie.

>>> def foo(a, b, c=4, *arglist, **keywords): pass
>>> inspect.getfullargspec(foo)
(['a', 'b', 'c'], 'arglist', 'keywords', (4,))

Note that some callables may not be introspectable in certain implementations of Python. For Example, in CPython, some built-in functions defined in C provide no metadata about their arguments. As a result, you will get a ValueError if you use inspect.getfullargspec() on a built-in function.

Since Python 3.3, you can use inspect.signature() to see the call signature of a callable object:

>>> inspect.signature(foo)
<Signature (a, b, c=4, *arglist, **keywords)>

How do you change the server header returned by nginx?

According to nginx documentation it supports custom values or even the exclusion:

Syntax: server_tokens on | off | build | string;

but sadly only with a commercial subscription:

Additionally, as part of our commercial subscription, starting from version 1.9.13 the signature on error pages and the “Server” response header field value can be set explicitly using the string with variables. An empty string disables the emission of the “Server” field.

How to use store and use session variables across pages?

Try this:

<!-- first page -->
<?php
  session_start(); 
  session_register('myvar');
  $_SESSION['myvar'] == 'myvalue';
?>

<!-- second page -->
<?php
    session_start();
    echo("1");
    if(session_is_registered('myvar'))
    {
        echo("2");
       if($_SESSION['myvar'] == 'myvalue')
       {
           echo("3");
           exit;
       }
    }
    ?>

Bootstrap 3 unable to display glyphicon properly

First of all, I try to install the glyphicons fonts by the "oficial" way, with the zip file. I could not do it.

This is my step-by-step solution:

  1. Go to the web page of Bootstrap and then to the "Components" section.
  2. Open the browser console. In Chrome, Ctrl+Shift+C.
  3. In section Resources, inside Frames/getbootstrap.com/Fonts you will find the font that actually is running the glyphicons. It's recommended to use the private mode to evade cache.
  4. With URL of the font file (right-click on the file showed on resources list), copy it in a new tab, and press ENTER. This will download the font file.
  5. Copy another time the URL in a tab and change the font extension to eot, ttf, svg or woff, ass you like.

However, for a more easy acces, this is the link of the woff file.

http://getbootstrap.com/dist/fonts/glyphicons-halflings-regular.woff

Angular 5 ngHide ngShow [hidden] not working

If you want to just toggle visibility and still keep the input in DOM:

<input class="txt" type="password" [(ngModel)]="input_pw" 
 [style.visibility]="isHidden? 'hidden': 'visible'">

The other way around is as per answer by rrd, which is to use HTML hidden attribute. In an HTML element if hidden attribute is set to true browsers are supposed to hide the element from display, but the problem is that this behavior is overridden if the element has an explicit display style mentioned.

_x000D_
_x000D_
.hasDisplay {_x000D_
  display: block;_x000D_
}
_x000D_
<input class="hasDisplay" hidden value="shown" />_x000D_
<input hidden value="not shown">
_x000D_
_x000D_
_x000D_

To overcome this you can opt to use an explicit css for [hidden] that overrides the display;

[hidden] {
  display: none !important;
}

Yet another way is to have a is-hidden class and do:

<input [class.is-hidden]="isHidden"/>

.is-hidden {
      display: none;
 }

If you use display: none the element will be skipped from the static flow and no space will be allocated for the element, if you use visibility: hidden it will be included in the flow and a space will be allocated but it will be blank space.

The important thing is to use one way across an application rather than mixing different ways thereby making the code less maintainable.

If you want to remove it from DOM

<input class="txt" type="password" [(ngModel)]="input_pw" *ngIf="!isHidden">

How can I truncate a double to only two decimal places in Java?

Formating as a string and converting back to double i think will give you the result you want.

The double value will not be round(), floor() or ceil().

A quick fix for it could be:

 String sValue = (String) String.format("%.2f", oldValue);
 Double newValue = Double.parseDouble(sValue);

You can use the sValue for display purposes or the newValue for calculation.

How to get absolute path to file in /resources folder of your project

To return a file or filepath

URL resource = YourClass.class.getResource("abc");
File file = Paths.get(resource.toURI()).toFile(); // return a file
String filepath = Paths.get(resource.toURI()).toFile().getAbsolutePath();  // return file path

Is it possible to change the radio button icon in an android radio button group

yes....` from Xml

android:button="@drawable/yourdrawable" 

and from Java

myRadioButton.setButtonDrawable(resourceId or Drawable);

`

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

I had this on Ubuntu and as I've figured out, there was more than one instance of mysqld.

It looked like the previous one had not been completely stopped, while the new one has already started. Running '/etc/init.d/mysql stop' didn't help, it was always returning 'OK' and a new instance has been launched automatically immediately after that:

        $ sudo /etc/init.d/mysql stop
         * Stopping MySQL database server mysqld        [ OK ] 
        $ pgrep mysql
        28315
        $ sudo /etc/init.d/mysql stop
         * Stopping MySQL database server mysqld        [ OK ] 
        $ pgrep mysql
        28570
        $ sudo /etc/init.d/mysql stop
         * Stopping MySQL database server mysqld        [ OK ] 
        $ pgrep mysql
        28763
        ..... etc ...

Fortunately, the following command has fixed the problem:

    $ sudo service mysql stop
    mysql stop/waiting

    $ ps -ef | grep mysql
    29841 26858  0 10:59 pts/8    00:00:00 grep --color=auto mysql <--- IT's gone ! 

After that I was able to start mysql again and see that mysql.sock has been successfully created.

PHP function overloading

PHP doesn't support traditional method overloading, however one way you might be able to achieve what you want, would be to make use of the __call magic method:

class MyClass {
    public function __call($name, $args) {

        switch ($name) {
            case 'funcOne':
                switch (count($args)) {
                    case 1:
                        return call_user_func_array(array($this, 'funcOneWithOneArg'), $args);
                    case 3:
                        return call_user_func_array(array($this, 'funcOneWithThreeArgs'), $args);
                 }
            case 'anotherFunc':
                switch (count($args)) {
                    case 0:
                        return $this->anotherFuncWithNoArgs();
                    case 5:
                        return call_user_func_array(array($this, 'anotherFuncWithMoreArgs'), $args);
                }
        }
    }

    protected function funcOneWithOneArg($a) {

    }

    protected function funcOneWithThreeArgs($a, $b, $c) {

    }

    protected function anotherFuncWithNoArgs() {

    }

    protected function anotherFuncWithMoreArgs($a, $b, $c, $d, $e) {

    }

}

invalid_client in google oauth2

Another thing to check:

When you install the GoogleAPIs into a .Net app with NuGet, it will inject a new set of dummy values in your *.config file.

Check that any original values are still in place, and remove dummy entries.

What does "for" attribute do in HTML <label> tag?

It labels whatever input is the parameter for the for attribute.

_x000D_
_x000D_
<input id='myInput' type='radio'>_x000D_
<label for='myInput'>My 1st Radio Label</label>_x000D_
<br>_x000D_
<input id='input2' type='radio'>_x000D_
<label for='input2'>My 2nd Radio Label</label>_x000D_
<br>_x000D_
<input id='input3' type='radio'>_x000D_
<label for='input3'>My 3rd Radio Label</label>
_x000D_
_x000D_
_x000D_

Get list of filenames in folder with Javascript

For client side files, you cannot get a list of files in a user's local directory.

If the user has provided uploaded files, you can access them via their input element.

<input type="file" name="client-file" id="get-files" multiple />


<script>
var inp = document.getElementById("get-files");
// Access and handle the files 

for (i = 0; i < inp.files.length; i++) {
    let file = inp.files[i];
    // do things with file
}
</script>

How to deploy a war file in JBoss AS 7?

Just copy war file to standalone/deployments/ folder, it should deploy it automatically. It'll also create your_app_name.deployed file, when your application is deployed. Also be sure that you start server with bin/standalone.sh script.

What exactly does the .join() method do?

To append a string, just concatenate it with the + sign.

E.g.

>>> a = "Hello, "
>>> b = "world"
>>> str = a + b
>>> print str
Hello, world

join connects strings together with a separator. The separator is what you place right before the join. E.g.

>>> "-".join([a,b])
'Hello, -world'

Join takes a list of strings as a parameter.

How do I center text vertically and horizontally in Flutter?

maybe u want to provide the same width and height for 2 container

Container(
            width: size.width * 0.30, height: size.height * 0.4,
            alignment: Alignment.center,
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(6)
            ),
            child: Center(
              child: Text(categoryName, textAlign: TextAlign.center, style: TextStyle(
                fontWeight: FontWeight.bold,
                fontSize: 17,
                color: Colors.white,
              ),),
            ),

rails generate model

The code is okay but you are in the wrong directory. You must run these commands inside your rails project-directory.

The normal way to get there from scratch is:

$ rails new PROJECT_NAME
$ cd PROJECT_NAME
$ rails generate model ad \
    name:string \ 
    description:text \
    price:decimal \
    seller_id:integer \
    email:string img_url:string

How to run Visual Studio post-build events for debug build only

Like any project setting, the buildevents can be configured per Configuration. Just select the configuration you want to change in the dropdown of the Property Pages dialog and edit the post build step.

If...Then...Else with multiple statements after Then

Multiple statements are to be separated by a new line:

If SkyIsBlue Then
  StartEngines
  Pollute
ElseIf SkyIsRed Then
  StopAttack
  Vent
ElseIf SkyIsYellow Then
  If Sunset Then
    Sleep
  ElseIf Sunrise or IsMorning Then
    Smoke
    GetCoffee
  Else
    Error
  End If
Else
  Joke
  Laugh
End If

Installing NumPy via Anaconda in Windows

Yep you should start anaconda's python in order to use python libs which come with anaconda. Or otherwise you have to manually add anaconda\lib to pythonpath which is less trivial. You can start anaconda's python by a full path:

path\to\anaconda\python.exe

or you can run the following two commands as an admin in cmd to make windows pipe every .py file to anaconda's python:

assoc .py=Python.File
ftype Python.File=C:\path\to\Anaconda\python.exe "%1" %*

after this you'll be able just to call python scripts without specifying the python executable at all.

ISO C90 forbids mixed declarations and code in C

I think you should move the variable declaration to top of block. I.e.

{
    foo();
    int i = 0;
    bar();
}

to

{
    int i = 0;
    foo();
    bar();
}

Where should I put the CSS and Javascript code in an HTML webpage?

CSS includes should go in the head before any js script includes. Javascript can go anywhere, but really the function of the file could determine the location. If it builds page content put it on the head. If its used for events or tracking, you can put it before the </body>

Jquery UI tooltip does not support html content

add html = true to the tooltip options

$({selector}).tooltip({html: true});

Update
it's not relevant for jQuery ui tooltip property - it's true in bootstrap ui tooltip - my bad!

How to show live preview in a small popup of linked page on mouse over on link?

HTML structure

<div id="app">
<div class="box">
    <div class="title">How to preview link with iframe and javascript?</div>
    <div class="note"><small>Note: Click to every link on content below to preview</small></div>
    <div id="content">
        We'll first attach all the events to all the links for which we want to <a href="https://htmlcssdownload.com/">preview</a> with the addEventListener method. In this method we will create elements including the floating frame containing the preview pane, the preview pane off button, the iframe button to load the preview content.
    </div>
    <h3>Preview the link</h3>
    <div id="result"></div>
</div>

We'll first attach all the events to all the links for which we want to preview with the addEventListener method. In this method we will create elements including the floating frame containing the preview pane, the preview pane off button, the iframe button to load the preview content.

<script type="text/javascript">
(()=>{
    let content = document.getElementById('content');
    let links = content.getElementsByTagName('a');
    for (let index = 0; index < links.length; index++) {
        const element = links[index];
        element.addEventListener('click',(e)=>{
            e.preventDefault();
            openDemoLink(e.target.href);
        })
    }

    function openDemoLink(link){

        let div = document.createElement('div');
        div.classList.add('preview_frame');
        
        let frame = document.createElement('iframe');
        frame.src = link;
        
        let close = document.createElement('a');
        close.classList.add('close-btn');
        close.innerHTML = "Click here to close the example";
        close.addEventListener('click', function(e){
            div.remove();
        })
        
        div.appendChild(frame);
        div.appendChild(close);
        
        document.getElementById('result').appendChild(div);
    }
})()

To see detail at How to live preview link

Setting size for icon in CSS

Funnily enough, adjusting the padding seems to do it.

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_x000D_
.arrow {
  border: solid rgb(2, 0, 0);
  border-width: 0 3px 3px 0;
  display: inline-block;
}

.first{
  padding: 2vh;
}

.second{
  padding: 4vh;
}

.left {
    transform: rotate(135deg);
    -webkit-transform: rotate(135deg);
 }
_x000D_
<i class="arrow first left"></i>
<i class="arrow second left"></i>
_x000D_
_x000D_
_x000D_

Manifest Merger failed with multiple errors in Android Studio

In my case it was showing an error because there was a redundancy in <uses-permission> element. So, please check in your AndroidManifest.xml file for the same.

Android Studio version is 3.0.1

Operating System is Windows 7

Here is the screenshot for reference.

Screen-shot which shows redundancy in manifest file.

jQuery event for images loaded

As per this answer, you can use the jQuery load event on the window object instead of the document:

jQuery(window).load(function() {
    console.log("page finished loading now.");
});

This will be triggered after all content on the page has been loaded. This differs from jQuery(document).load(...) which is triggered after the DOM has finished loading.

How can I extract a number from a string in JavaScript?

please check below javaScripts, there you can get only number

_x000D_
_x000D_
var txt = "abc1234char5678#!9";_x000D_
var str = txt.match(/\d+/g, "")+'';_x000D_
var s = str.split(',').join('');_x000D_
alert(Number(s));
_x000D_
_x000D_
_x000D_

output : 1234567789

sqlplus how to find details of the currently connected database session

select * from v$session
where sid = to_number(substr(dbms_session.unique_session_id,1,4),'XXXX')

What is a StackOverflowError?

Like you say, you need to show some code. :-)

A stack overflow error usually happens when your function calls nest too deeply. See the Stack Overflow Code Golf thread for some examples of how this happens (though in the case of that question, the answers intentionally cause stack overflow).

How do I make a newline after a twitter bootstrap element?

You're using span6 and span2. Both of these classes are "float:left" meaning, if possible they will always try to sit next to each other. Twitter bootstrap is based on a 12 grid system. So you should generally always get the span**#** to add up to 12.

E.g.: span4 + span4 + span4 OR span6 + span6 OR span4 + span3 + span5.

To force a span down though, without listening to the previous float you can use twitter bootstraps clearfix class. To do this, your code should look like this:

<ul class="nav nav-tabs span2">
  <li><a href="./index.html"><i class="icon-black icon-music"></i></a></li>
  <li><a href="./about.html"><i class="icon-black icon-eye-open"></i></a></li>
  <li><a href="./team.html"><i class="icon-black icon-user"></i></a></li>
  <li><a href="./contact.html"><i class="icon-black icon-envelope"></i></a></li>
</ul>
<!-- Notice this following line -->
<div class="clearfix"></div>
<div class="well span6">
  <h3>I wish this appeared on the next line without having to gratuitously use BR!</h3>
</div>

MVC Razor Hidden input and passing values

First of all ASP.NET MVC does not work the same way WebForms does. You don't have the whole runat="server" thing. MVC does not offer the abstraction layer that WebForms offered. Probabaly you should try to understand what controllers and actions are and then you should look at model binding. Any beginner level tutorial about MVC shows how you can pass data between the client and the server.

How to write PNG image to string with the PIL?

With modern (as of mid-2017 Python 3.5 and Pillow 4.0):

StringIO no longer seems to work as it used to. The BytesIO class is the proper way to handle this. Pillow's save function expects a string as the first argument, and surprisingly doesn't see StringIO as such. The following is similar to older StringIO solutions, but with BytesIO in its place.

from io import BytesIO
from PIL import Image

image = Image.open("a_file.png")
faux_file = BytesIO()
image.save(faux_file, 'png')

Gaussian filter in MATLAB

In MATLAB R2015a or newer, it is no longer necessary (or advisable from a performance standpoint) to use fspecial followed by imfilter since there is a new function called imgaussfilt that performs this operation in one step and more efficiently.

The basic syntax:

B = imgaussfilt(A,sigma) filters image A with a 2-D Gaussian smoothing kernel with standard deviation specified by sigma.

The size of the filter for a given Gaussian standard deviation (sigam) is chosen automatically, but can also be specified manually:

B = imgaussfilt(A,sigma,'FilterSize',[3 3]);

The default is 2*ceil(2*sigma)+1.

Additional features of imgaussfilter are ability to operate on gpuArrays, filtering in frequency or spacial domain, and advanced image padding options. It looks a lot like IPP... hmmm. Plus, there's a 3D version called imgaussfilt3.

How do I validate a date in this format (yyyy-mm-dd) using jquery?

You could also just use regular expressions to accomplish a slightly simpler job if this is enough for you (e.g. as seen in [1]).

They are build in into javascript so you can use them without any libraries.

function isValidDate(dateString) {
  var regEx = /^\d{4}-\d{2}-\d{2}$/;
  return dateString.match(regEx) != null;
}

would be a function to check if the given string is four numbers - two numbers - two numbers (almost yyyy-mm-dd). But you can do even more with more complex expressions, e.g. check [2].

isValidDate("23-03-2012") // false
isValidDate("1987-12-24") // true
isValidDate("22-03-1981") // false
isValidDate("0000-00-00") // true

How to get a responsive button in bootstrap 3

<a href="#"><button type="button" class="btn btn-info btn-block regular-link"> <span class="text">Create New Board</span></button></a>

We can use btn-block for automatic responsive.

Android Studio with Google Play Services

I've got this working after doing the following:

  • Have the google-play-services-lib as a module (note difference between module and project), then add the google-play-services.jar to your models "libs" directory.
  • After that add the jar to your build path through making a library or add the jar to another library. I generally have a single IDEA library which I add all my /libs/*.jar files to.
  • Add the library to your modules build path through Module Settings (F4).
  • Add the google-play-services-lib as a module dependency to your project.
  • Done!

Note: This doesn't give me the runtime exceptions either, it works.

Request Permission for Camera and Library in iOS 10 - Info.plist

I wrote an extension that takes into account all possible cases:

  • If access is allowed, then the code onAccessHasBeenGranted will be run.
  • If access is not determined, then requestAuthorization(_:) will be called.
  • If the user has denied your app photo library access, then the user will be shown a window offering to go to settings and allow access. In this window, the "Cancel" and "Settings" buttons will be available to him. When he presses the "settings" button, your application settings will open.

Usage example:

PHPhotoLibrary.execute(controller: self, onAccessHasBeenGranted: {
    // access granted... 
})

Extension code:

import Photos
import UIKit

public extension PHPhotoLibrary {

   static func execute(controller: UIViewController,
                       onAccessHasBeenGranted: @escaping () -> Void,
                       onAccessHasBeenDenied: (() -> Void)? = nil) {

      let onDeniedOrRestricted = onAccessHasBeenDenied ?? {
         let alert = UIAlertController(
            title: "We were unable to load your album groups. Sorry!",
            message: "You can enable access in Privacy Settings",
            preferredStyle: .alert)
         alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
         alert.addAction(UIAlertAction(title: "Settings", style: .default, handler: { _ in
            if let settingsURL = URL(string: UIApplication.openSettingsURLString) {
               UIApplication.shared.open(settingsURL)
            }
         }))
         controller.present(alert, animated: true)
      }

      let status = PHPhotoLibrary.authorizationStatus()
      switch status {
      case .notDetermined:
         onNotDetermined(onDeniedOrRestricted, onAccessHasBeenGranted)
      case .denied, .restricted:
         onDeniedOrRestricted()
      case .authorized:
         onAccessHasBeenGranted()
      @unknown default:
         fatalError("PHPhotoLibrary::execute - \"Unknown case\"")
      }
   }

}

private func onNotDetermined(_ onDeniedOrRestricted: @escaping (()->Void), _ onAuthorized: @escaping (()->Void)) {
   PHPhotoLibrary.requestAuthorization({ status in
      switch status {
      case .notDetermined:
         onNotDetermined(onDeniedOrRestricted, onAuthorized)
      case .denied, .restricted:
         onDeniedOrRestricted()
      case .authorized:
         onAuthorized()
      @unknown default:
         fatalError("PHPhotoLibrary::execute - \"Unknown case\"")
      }
   })
}

<SELECT multiple> - how to allow only one item selected?

You want only one option by default, but the user can select multiple options by pressing the CTRL key. This is (already) exactly how the SELECT multiple is meant to behave.

See this: http://www.w3schools.com/tags/tryit.asp?filename=tryhtml_select_multiple

Can you please clarify your question?

Excel formula to search if all cells in a range read "True", if not, then show "False"

You can just AND the results together if they are stored as TRUE / FALSE values:

=AND(A1:D2)

Or if stored as text, use an array formula - enter the below and press Ctrl+Shift+Enter instead of Enter.

=AND(EXACT(A1:D2,"TRUE"))

How to import module when module name has a '-' dash or hyphen in it?

If you can't rename the module to match Python naming conventions, create a new module to act as an intermediary:

 ---- foo_proxy.py ----
 tmp = __import__('foo-bar')
 globals().update(vars(tmp))

 ---- main.py ----
 from foo_proxy import * 

Adding days to a date in Java

Simple, without any other API:

To add 8 days:

Date today=new Date();
long ltime=today.getTime()+8*24*60*60*1000;
Date today8=new Date(ltime);

How to highlight a selected row in ngRepeat?

You probably want to have LI rather than the UL have the background-color:

.selected li {
  background-color: red;
}

Then you want to have a dynamic class for the UL:

<ul ng-repeat="vote in votes" ng-click="setSelected()" class="{{selected}}">

Now you need to update the $scope.selected when clicking the row:

$scope.setSelected = function() {
   console.log("show", arguments, this);
   this.selected = 'selected';
}

and then un-select the previously highlighted row:

$scope.setSelected = function() {
   // console.log("show", arguments, this);
   if ($scope.lastSelected) {
     $scope.lastSelected.selected = '';
   }
   this.selected = 'selected';
   $scope.lastSelected = this;
}

Working solution:

http://plnkr.co/edit/wq6nxc?p=preview

How do you calculate log base 2 in Java for integers?

you can use the identity

            log[a]x
 log[b]x = ---------
            log[a]b

so this would be applicable for log2.

            log[10]x
 log[2]x = ----------
            log[10]2

just plug this into the java Math log10 method....

http://mathforum.org/library/drmath/view/55565.html

HTML combo box with option to type an entry

    <html>
<head>
    <title></title>
    <script src="jquery-3.1.0.js"></script>
    <script>
        $(function () {
            $('#selectnumber').change(function(){
                alert('.val() = ' + $('#selectnumber').val() + '  AND  html() = ' + $('#selectnumber option:selected').html() + '  AND .text() = ' + $('#selectnumber option:selected').text());
            })
        });
    </script>
</head>
<body>
       <div>
        <select id="selectnumber">
            <option value="1">one</option>
            <option value="2">two</option>
            <option value="3">three</option>
            <option value="4">four</option>
        </select>

    </div>
   </body>
</html>

Click to see OutPut Screen

Thanks...:)

XMLHttpRequest cannot load XXX No 'Access-Control-Allow-Origin' header

Target server must allowed cross-origin request. In order to allow it through express, simply handle http options request :

app.options('/url...', function(req, res, next){
   res.header('Access-Control-Allow-Origin', "*");
   res.header('Access-Control-Allow-Methods', 'POST');
   res.header("Access-Control-Allow-Headers", "accept, content-type");
   res.header("Access-Control-Max-Age", "1728000");
   return res.sendStatus(200);
});

How to make <a href=""> link look like a button?

A simple as that :

<a href="#" class="btn btn-success" role="button">link</a>

Just add "class="btn btn-success" & role=button

Create a new RGB OpenCV image using Python?

The new cv2 interface for Python integrates numpy arrays into the OpenCV framework, which makes operations much simpler as they are represented with simple multidimensional arrays. For example, your question would be answered with:

import cv2  # Not actually necessary if you just want to create an image.
import numpy as np
blank_image = np.zeros((height,width,3), np.uint8)

This initialises an RGB-image that is just black. Now, for example, if you wanted to set the left half of the image to blue and the right half to green , you could do so easily:

blank_image[:,0:width//2] = (255,0,0)      # (B, G, R)
blank_image[:,width//2:width] = (0,255,0)

If you want to save yourself a lot of trouble in future, as well as having to ask questions such as this one, I would strongly recommend using the cv2 interface rather than the older cv one. I made the change recently and have never looked back. You can read more about cv2 at the OpenCV Change Logs.

How do I uniquely identify computers visiting my web site?

Really, what you want to do cannot be done because the protocols do not allow for this. If static IPs were universally used then you might be able to do it. They are not, so you cannot.

If you really want to identify people, have them log in.

Since they will probably be moving around to different pages on your web site, you need a way to keep track of them as they move about.

So long as they are logged in, and you are tracking their session within your site via cookies/link-parameters/beacons/whatever, you can be pretty sure that they are using the same computer during that time.

Ultimately, it is incorrect to say this tells you which computer they are using if your users are not using your own local network and do not have static IP addresses.

If what you want to do is being done with the cooperation of the users and there is only one user per cookie and they use a single web browser, just use a cookie.

Reset git proxy to default configuration

On my Linux machine :

git config --system --get https.proxy (returns nothing)
git config --global --get https.proxy (returns nothing)

git config --system --get http.proxy (returns nothing)
git config --global --get http.proxy (returns nothing)

I found out my https_proxy and http_proxy are set, so I just unset them.

unset https_proxy
unset http_proxy

On my Windows machine :

set https_proxy=""
set http_proxy=""

Optionally use setx to set environment variables permanently on Windows and set system environment using "/m"

setx https_proxy=""
setx http_proxy=""

How to set timeout on python's socket recv method?

#! /usr/bin/python3.6

# -*- coding: utf-8 -*-
import socket
import time
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
s.settimeout(5)
PORT = 10801

s.bind(('', PORT))
print('Listening for broadcast at ', s.getsockname())
BUFFER_SIZE = 4096
while True:
    try:
        data, address = s.recvfrom(BUFFER_SIZE)
    except socket.timeout:
        print("Didn't receive data! [Timeout 5s]")
        continue

C# windows application Event: CLR20r3 on application start

Have been fighting this all morning and now have it solved and why it happened. Posting with the hope it helps others

I installed the Krypton.Toolkit which added the tools to the Visual studio toolbox automatically. I then added the tools to the designer, which automatically added the dll to the projrect references, however the toolkit was marked as CopyLocal=false

I built an installer, using all dlls in the release build folder (of course the above dll wasn't there).

Setting copylocal=true, then rebuilding the installer, everything worked fine.

C++ cast to derived class

You can't cast a base object to a derived type - it isn't of that type.

If you have a base type pointer to a derived object, then you can cast that pointer around using dynamic_cast. For instance:

DerivedType D;
BaseType B;

BaseType *B_ptr=&B
BaseType *D_ptr=&D;// get a base pointer to derived type

DerivedType *derived_ptr1=dynamic_cast<DerivedType*>(D_ptr);// works fine
DerivedType *derived_ptr2=dynamic_cast<DerivedType*>(B_ptr);// returns NULL

Including a css file in a blade template?

<link rel="stylesheet" href="{{ URL::asset('css/styles.css') }}">

It will search for the file in your project public folder

Pie chart with jQuery

Chart.js is quite useful, supporting numerous other types of charts as well.

It can be used both with jQuery and without.

How to make link not change color after visited?

(Header CSS:)

<style>

a  {   
   color: #ccc;   /* original colour state*/
}

a:active {
   color: #F66;  
}


a[tabindex]:focus {
    color: #F66;
    outline: none;
}

</style>


(Body HTML:)

<a href="javascript:;" style="font-size:36px; text-decoration:none;"  tabindex="1">click me &#9829;</a>

Drop all the tables, stored procedures, triggers, constraints and all the dependencies in one sql statement

Here I found new query to delete all sp,functions and triggers

declare @procName varchar(500)
declare cur cursor 

for select [name] from sys.objects where type = 'p'
open cur
fetch next from cur into @procName
while @@fetch_status = 0
begin
    exec('drop procedure ' + @procName)
    fetch next from cur into @procName
end
close cur
deallocate cur

Pandas dataframe fillna() only some columns in place

You can using dict , fillna with different value for different column

df.fillna({'a':0,'b':0})
Out[829]: 
     a    b    c
0  1.0  4.0  NaN
1  2.0  5.0  NaN
2  3.0  0.0  7.0
3  0.0  6.0  8.0

After assign it back

df=df.fillna({'a':0,'b':0})
df
Out[831]: 
     a    b    c
0  1.0  4.0  NaN
1  2.0  5.0  NaN
2  3.0  0.0  7.0
3  0.0  6.0  8.0

Detecting when a div's height changes using jQuery

You can use MutationObserver class.

MutationObserver provides developers a way to react to changes in a DOM. It is designed as a replacement for Mutation Events defined in the DOM3 Events specification.

Example (source)

// select the target node
var target = document.querySelector('#some-id');

// create an observer instance
var observer = new MutationObserver(function(mutations) {
  mutations.forEach(function(mutation) {
    console.log(mutation.type);
  });    
});

// configuration of the observer:
var config = { attributes: true, childList: true, characterData: true };

// pass in the target node, as well as the observer options
observer.observe(target, config);

// later, you can stop observing
observer.disconnect();

How to install APK from PC?

Just connect the device to the PC with a USB cable, then copy the .apk file to the device. On the device, touch the APK file in the file explorer to install it.

You could also offer the .apk on your website. People can download it, then touch it to install.

How do I use vim registers?

One overlooked register is the '.' dot register which contains the last inserted text no matter how it was inserted eg ct] (change till ]). Then you realise you need to insert it elsewhere but can't use the dot repeat method.

 :reg .
 :%s/fred/<C-R>./

Modify a Column's Type in sqlite3

If you prefer a GUI, DB Browser for SQLite will do this with a few clicks.

  1. "File" - "Open Database"
  2. In the "Database Structure" tab, click on the table content (not table name), then "Edit" menu, "Modify table", and now you can change the data type of any column with a drop down menu. I changed a 'text' field to 'numeric' in order to retrieve data in a number range.

DB Browser for SQLite is open source and free. For Linux it is available from the repository.

Nested routes with react router v4 / v5

In react-router-v4 you don't nest <Routes />. Instead, you put them inside another <Component />.


For instance

<Route path='/topics' component={Topics}>
  <Route path='/topics/:topicId' component={Topic} />
</Route>

should become

<Route path='/topics' component={Topics} />

with

const Topics = ({ match }) => (
  <div>
    <h2>Topics</h2>
    <Link to={`${match.url}/exampleTopicId`}>
      Example topic
    </Link>
    <Route path={`${match.path}/:topicId`} component={Topic}/>
  </div>
) 

Here is a basic example straight from the react-router documentation.

How to disable anchor "jump" when loading a page?

See my answer here: Stackoverflow Answer

The trick is to just remove the hashtag ASAP and store its value for your own use:

It is important that you do not put that part of the code in the $() or $(window).load() functions as it would be too late and the browser already has moved to the tag.

// store the hash (DON'T put this code inside the $() function, it has to be executed 
// right away before the browser can start scrolling!
var target = window.location.hash,
    target = target.replace('#', '');

// delete hash so the page won't scroll to it
window.location.hash = "";

// now whenever you are ready do whatever you want
// (in this case I use jQuery to scroll to the tag after the page has loaded)
$(window).on('load', function() {
    if (target) {
        $('html, body').animate({
            scrollTop: $("#" + target).offset().top
        }, 700, 'swing', function () {});
    }
});

Function to Calculate a CRC16 Checksum

for (pos = 0; pos < len; pos++) {
    crc ^= (uint16_t)buf[pos];     // XOR byte into least sig. byte of crc

    for (i = 8; i != 0; i--) {     // Loop over each bit
        if ((crc & 0x0001) != 0) { // If the LSB is set
            crc >>= 1;             // Shift right and XOR 0xA001
            crc ^= CRC16;
        } else {                   // Else LSB is not set
            crc >>= 1;             // Just shift right
        }
     }
}

return crc;

Storing Data in MySQL as JSON

Everybody commenting seems to be coming at this from the wrong angle, it is fine to store JSON code via PHP in a relational DB and it will in fact be faster to load and display complex data like this, however you will have design considerations such as searching, indexing etc.

The best way of doing this is to use hybrid data, for example if you need to search based upon datetime MySQL (performance tuned) is going to be a lot faster than PHP and for something like searching distance of venues MySQL should also be a lot faster (notice searching not accessing). Data you do not need to search on can then be stored in JSON, BLOB or any other format you really deem necessary.

Data you need to access is very easily stored as JSON for example a basic per-case invoice system. They do not benefit very much at all from RDBMS, and could be stored in JSON just by json_encoding($_POST['entires']) if you have the correct HTML form structure.

I am glad you are happy using MongoDB and I hope that it continues to serve you well, but don't think that MySQL is always going to be off your radar, as your app increases in complexity you may well end up needing an RDBMS for some functionality and features (even if it is just for retiring archived data or business reporting)

What is the ideal data type to use when storing latitude / longitude in a MySQL database?

  1. Latitudes range from -90 to +90 (degrees), so DECIMAL(10, 8) is ok for that

  2. longitudes range from -180 to +180 (degrees) so you need DECIMAL(11, 8).

Note: The first number is the total number of digits stored, and the second is the number after the decimal point.

In short: lat DECIMAL(10, 8) NOT NULL, lng DECIMAL(11, 8) NOT NULL

Format date to MM/dd/yyyy in JavaScript

ISO compliant dateString

If your dateString is RFC282 and ISO8601 compliant:
pass your string into the Date Constructor:

const dateString = "2020-10-30T12:52:27+05:30"; // ISO8601 compliant dateString
const D = new Date(dateString);                 // {object Date}

from here you can extract the desired values by using Date Getters:

D.getMonth() + 1  // 10 (PS: +1 since Month is 0-based)
D.getDate()       // 30
D.getFullYear()   // 2020

Non-standard date string

If you use a non standard date string:
destructure the string into known parts, and than pass the variables to the Date Constructor:

new Date(year, monthIndex [, day [, hours [, minutes [, seconds [, milliseconds]]]]])

const dateString = "30/10/2020 12:52:27";
const [d, M, y, h, m, s] = dateString.match(/\d+/g);

// PS: M-1 since Month is 0-based
const D = new Date(y, M-1, d, h, m, s);  // {object Date}


D.getMonth() + 1  // 10 (PS: +1 since Month is 0-based)
D.getDate()       // 30
D.getFullYear()   // 2020

How do I script a "yes" response for installing programs?

Although this may be more complicated/heavier-weight than you want, one very flexible way to do it is using something like Expect (or one of the derivatives in another programming language).

Expect is a language designed specifically to control text-based applications, which is exactly what you are looking to do. If you end up needing to do something more complicated (like with logic to actually decide what to do/answer next), Expect is the way to go.

clearing select using jquery

For most of my select options, I start off with an option that simply says 'Please Select' or something similar and that option is always disabled. Then whenever you want to clear your select/option's you can do just do something like this.

Example

<select id="mySelectOption">
   <option value="" selected disabled>Please select</option>
</select>

Answer

$('#mySelectOption').val('Please Select');

Capture the screen shot using .NET

It's certainly possible to grab a screenshot using the .NET Framework. The simplest way is to create a new Bitmap object and draw into that using the Graphics.CopyFromScreen method.

Sample code:

using (Bitmap bmpScreenCapture = new Bitmap(Screen.PrimaryScreen.Bounds.Width, 
                                            Screen.PrimaryScreen.Bounds.Height))
using (Graphics g = Graphics.FromImage(bmpScreenCapture))
{
    g.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
                     Screen.PrimaryScreen.Bounds.Y,
                     0, 0,
                     bmpScreenCapture.Size,
                     CopyPixelOperation.SourceCopy);
}

Caveat: This method doesn't work properly for layered windows. Hans Passant's answer here explains the more complicated method required to get those in your screen shots.

json_encode function: special characters

To fix the special character issue you just have to do 2 things

1.mysql_set_charset('utf8'); // set this line on top of your page in which you are using json.

  1. If you are saving json data in database make sure that the particular column collation is set to "latin1_swedish_ci".

scroll image with continuous scrolling using marquee tag

You cannot scroll images continuously using the HTML marquee tag - it must have JavaScript added for the continuous scrolling functionality.

There is a JavaScript plugin called crawler.js available on the dynamic drive forum for achieving this functionality. This plugin was created by John Davenport Scheuer and has been modified over time to suit new browsers.

I have also implemented this plugin into my blog to document all the steps to use this plugin. Here is the sample code:

<head>
    <script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>
    <script src="assets/js/crawler.js" type="text/javascript" ></script>
</head>

<div id="mycrawler2" style="margin-top: -3px; " class="productswesupport">
    <img src="assets/images/products/ie.png" />
    <img src="assets/images/products/browser.png" />
    <img src="assets/images/products/chrome.png" />
    <img src="assets/images/products/safari.png" />
</div>

Here is the plugin configration:

marqueeInit({
    uniqueid: 'mycrawler2',
    style: {
    },
    inc: 5, //speed - pixel increment for each iteration of this marquee's movement
    mouse: 'cursor driven', //mouseover behavior ('pause' 'cursor driven' or false)
    moveatleast: 2,
    neutral: 150,
    savedirection: true,
    random: true
});

Kotlin's List missing "add", "remove", Map missing "put", etc?

https://kotlinlang.org/docs/reference/collections.html

According to above link List<E> is immutable in Kotlin. However this would work:

var list2 = ArrayList<String>()
list2.removeAt(1)

How to iterate a table rows with JQuery and access some cell values?

try this

var value = iterate('tr.item span.value');
var quantity = iterate('tr.item span.quantity');

function iterate(selector)
{
  var result = '';
  if ($(selector))
  {
    $(selector).each(function ()
    {
      if (result == '')
      {
        result = $(this).html();
      }
      else
      {
        result = result + "," + $(this).html();
      }
    });
  }
}

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

After some messing around this is how I got the desired look (at least in the emulator) and it keeps the ripple effect.

tab layout with tab selector with color argument

<com.google.android.material.tabs.TabLayout
    android:id="@+id/tabs"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:tabBackground="@drawable/tab_selector"
    app:tabIconTint="@drawable/tab_selector"
    app:tabIconTintMode="src_atop"
    app:tabTextColor="@drawable/tab_selector" />

And the @drawable/tab_selector:

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:color="@color/colorPrimary" android:drawable="@color/colorPrimaryDark" android:state_selected="true" />
    <item android:color="@color/colorPrimaryDark" android:drawable="@color/colorPrimary" />
</selector>

FYI: This is what the emulator showed before I added the color argument to @drawable/tab_selector:

tab layout with tab selector without color argument

JSON date to Java date?

Note that SimpleDateFormat format pattern Z is for RFC 822 time zone and pattern X is for ISO 8601 (this standard supports single letter time zone names like Z for Zulu).

So new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSX") produces a format that can parse both "2013-03-11T01:38:18.309Z" and "2013-03-11T01:38:18.309+0000" and will give you the same result.

Unfortunately, as far as I can tell, you can't get this format to generate the Z for Zulu version, which is annoying.

I actually have more trouble on the JavaScript side to deal with both formats.

make iframe height dynamic based on content inside- JQUERY/Javascript

Other answers were not working for me so i did some changes. Hope this will help

$('#iframe').on("load", function() {
    var iframe = $(window.top.document).find("#iframe");
    iframe.height(iframe[0].ownerDocument.body.scrollHeight+'px' );
});

How to remove Firefox's dotted outline on BUTTONS as well as links?

Remove dotted outline from links, button and input element.

a:focus, a:active,
button::-moz-focus-inner,
input[type="reset"]::-moz-focus-inner,
input[type="button"]::-moz-focus-inner,
input[type="submit"]::-moz-focus-inner {
    border: 0;
    outline : 0;
}

How do I get current URL in Selenium Webdriver 2 Python?

Use current_url element for Python 2:

print browser.current_url

For Python 3 and later versions of selenium:

print(driver.current_url)

Live video streaming using Java?

You can do this today in Java with the Red5 media server from Flash. If you want to also decode and encode video in Java, you can use the Xuggler project.

Saving image to file

You can try with this code

Image.Save("myfile.png", ImageFormat.Png)

Link : http://msdn.microsoft.com/en-us/library/ms142147.aspx

Clear an input field with Reactjs?

I have a similar solution to @Satheesh using React hooks:

State initialization:

const [enteredText, setEnteredText] = useState(''); 

Input tag:

<input type="text" value={enteredText}  (event handler, classNames, etc.) />

Inside the event handler function, after updating the object with data from input form, call:

setEnteredText('');

Note: This is described as 'two-way binding'

How to get records randomly from the oracle database?

SELECT * FROM table SAMPLE(10) WHERE ROWNUM <= 20;

This is more efficient as it doesn't need to sort the Table.

Identifying and solving javax.el.PropertyNotFoundException: Target Unreachable

EL interprets ${bean.propretyName} as described - the propertyName becomes getPropertyName() on the assumption you are using explicit or implicit methods of generating getter/setters

You can override this behavior by explicitly identifying the name as a function: ${bean.methodName()} This calls the function method Name() directly without modification.

It isn't always true that your accessors are named "get...".

Clear the form field after successful submission of php form

You can use .reset() on your form.

$(".myform")[0].reset();

I do not want to inherit the child opacity from the parent in CSS

On mac you can use Preview editor to apply opacity to a white rectangle laid over your .png image before you put it in your .css.

1) Image
Logo

2) Create a rectangle around the image
Rectanle around logo

3) Change background color to white
rectangle turned white

4) Adjust rectangle opacity
opaque image

C# DateTime to UTC Time without changing the time

Use the DateTime.ToUniversalTime method.

JAVA Unsupported major.minor version 51.0

This is because of a higher JDK during compile time and lower JDK during runtime. So you just need to update your JDK version, possible to JDK 7

You may also check Unsupported major.minor version 51.0