Programs & Examples On #Revenue

Beginner Python: AttributeError: 'list' object has no attribute

You need to pass the values of the dict into the Bike constructor before using like that. Or, see the namedtuple -- seems more in line with what you're trying to do.

Filter rows which contain a certain string

This answer similar to others, but using preferred stringr::str_detect and dplyr rownames_to_column.

library(tidyverse)

mtcars %>% 
  rownames_to_column("type") %>% 
  filter(stringr::str_detect(type, 'Toyota|Mazda') )

#>             type  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
#> 1      Mazda RX4 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
#> 2  Mazda RX4 Wag 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
#> 3 Toyota Corolla 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
#> 4  Toyota Corona 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1

Created on 2018-06-26 by the reprex package (v0.2.0).

How to calculate percentage when old value is ZERO

When both values are zero, then the change is zero.

If one of the values is zero, it's infinite (ambiguous), but I would set it to 100%.

Here is a C++ code (where v1 is the previous value (old), and v2 is new):

double result = 0;
if (v1 != 0 && v2 != 0) {
  // If values are non-zero, use the standard formula.
  result = (v2 / v1) - 1;
} else if (v1 == 0 || v2 == 0) {
  // Change is zero when both values are zeros, otherwise it's 100%.
  result = v1 == 0 && v2 == 0 ? 0 : 1;
}
result = v2 > v1 ? abs(result) : -abs(result);
// Note: To have format in hundreds, multiply the result by 100.

jquery how to use multiple ajax calls one after the end of the other

Wrap each ajax call in a named function and just add them to the success callbacks of the previous call:

function callA() {
    $.ajax({
    ...
    success: function() {
      //do stuff
      callB();
    }
    });
}

function callB() {
    $.ajax({
    ...
    success: function() {
        //do stuff
        callC();
    }
    });
}

function callC() {
    $.ajax({
    ...
    });
}


callA();

Adding to a vector of pair

Read the following documentation:

http://cplusplus.com/reference/std/utility/make_pair/

or

http://en.cppreference.com/w/cpp/utility/pair/make_pair

I think that will help. Those sites are good resources for C++, though the latter seems to be the preferred reference these days.

XPath using starts-with function

Try this

//ITEM/*[starts-with(text(),'2552')]/following-sibling::*

SQL grouping by month and year

If I understand correctly. In order to group your results as requested, your Group By clause needs to have the same expression as your select statement.

GROUP BY MONTH(date) + '.' + YEAR(date)

To display the date as "month-date" format change the '.' to '-' The full syntax would be something like this.

SELECT MONTH(date) + '-' + YEAR(date) AS Mjesec, SUM(marketingExpense) AS
SumaMarketing, SUM(revenue) AS SumaZarada 
FROM [Order]
WHERE (idCustomer = 1) AND (date BETWEEN '2001-11-3' AND '2011-11-3')
GROUP BY MONTH(date) + '.' + YEAR(date)

How to detect Adblock on my website?

All of the answers above are valid, however most will not work for DNS-level ad blocking.

DNS-level ad blockers(like pi-hole) basically return NXDOMAIN(domain does not exist) for a list of ad blocking domains (e.g. telemetry.microsoft.com will "not exist" when it does).

There are a few ways to circumvent this:

Method A: Request for ads by ip address, not domain.

This method is a bit annoying as you would have to keep track of ip addresses. This will be problematic if your code isn't well maintained or updated regularly.

Method B: Block all requests that fail- even if the client reports NXDOMAIN.

This will be very annoying for users if it is a "legitimate" NXDOMAIN.

Can't access 127.0.0.1

In windows first check under services if world wide web publishing services is running. If not start it.

If you cannot find it switch on IIS features of windows: In 7,8,10 it is under control panel , "turn windows features on or off". Internet Information Services World Wide web services and Internet information Services Hostable Core are required. Not sure if there is another way to get it going on windows, but this worked for me for all browsers. You might need to add localhost or http:/127.0.0.1 to the trusted websites also under IE settings.

Unmarshaling nested JSON objects

Like what Volker mentioned, nested structs is the way to go. But if you really do not want nested structs, you can override the UnmarshalJSON func.

https://play.golang.org/p/dqn5UdqFfJt

type A struct {
    FooBar string // takes foo.bar
    FooBaz string // takes foo.baz
    More   string 
}

func (a *A) UnmarshalJSON(b []byte) error {

    var f interface{}
    json.Unmarshal(b, &f)

    m := f.(map[string]interface{})

    foomap := m["foo"]
    v := foomap.(map[string]interface{})

    a.FooBar = v["bar"].(string)
    a.FooBaz = v["baz"].(string)
    a.More = m["more"].(string)

    return nil
}

Please ignore the fact that I'm not returning a proper error. I left that out for simplicity.

UPDATE: Correctly retrieving "more" value.

node.js: cannot find module 'request'

if some module you cant find, try with Static URI, for example:

var Mustache = require("/media/fabio/Datos/Express/2_required_a_module/node_modules/mustache/mustache.js");

This example, run on Ubuntu Gnome 16.04 of 64 bits, node -v: v4.2.6, npm: 3.5.2 Refer to: Blog of Ben Nadel

C# - What does the Assert() method do? Is it still useful?

In a debug compilation, Assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true.

If you compile in Release, all Debug.Assert's are automatically left out.

How can I find non-ASCII characters in MySQL?

MySQL provides comprehensive character set management that can help with this kind of problem.

SELECT whatever
  FROM tableName 
 WHERE columnToCheck <> CONVERT(columnToCheck USING ASCII)

The CONVERT(col USING charset) function turns the unconvertable characters into replacement characters. Then, the converted and unconverted text will be unequal.

See this for more discussion. https://dev.mysql.com/doc/refman/8.0/en/charset-repertoire.html

You can use any character set name you wish in place of ASCII. For example, if you want to find out which characters won't render correctly in code page 1257 (Lithuanian, Latvian, Estonian) use CONVERT(columnToCheck USING cp1257)

how do I initialize a float to its max/min value?

You can use std::numeric_limits which is defined in <limits> to find the minimum or maximum value of types (As long as a specialization exists for the type). You can also use it to retrieve infinity (and put a - in front for negative infinity).

#include <limits>

//...

std::numeric_limits<float>::max();
std::numeric_limits<float>::min();
std::numeric_limits<float>::infinity();

As noted in the comments, min() returns the lowest possible positive value. In other words the positive value closest to 0 that can be represented. The lowest possible value is the negative of the maximum possible value.

There is of course the std::max_element and min_element functions (defined in <algorithm>) which may be a better choice for finding the largest or smallest value in an array.

Get table name by constraint name

ALL_CONSTRAINTS describes constraint definitions on tables accessible to the current user.

DBA_CONSTRAINTS describes all constraint definitions in the database.

USER_CONSTRAINTS describes constraint definitions on tables in the current user's schema

Select CONSTRAINT_NAME,CONSTRAINT_TYPE ,TABLE_NAME ,STATUS from 
USER_CONSTRAINTS;

C++ undefined reference to defined function

You need to compile and link all your source files together:

g++ main.c function_file.c

Method to get all files within folder and subfolders that will return a list

This is for anyone that is trying to get a list of all files in a folder and its sub-folders and save it in a text document. Below is the full code including the “using” statements, “namespace”, “class”, “methods” etc. I tried commenting as much as possible throughout the code so you could understand what each part is doing. This will create a text document that contains a list of all files in all folders and sub-folders of any given root folder. After all, what good is a list (like in Console.WriteLine) if you can’t do something with it. Here I have created a folder on the C drive called “Folder1” and created a folder inside that one called “Folder2”. Next I filled folder2 with a bunch of files, folders and files and folders within those folders. This example code will get all the files and create a list in a text document and place that text document in Folder1. Caution: you shouldn’t save the text document to Folder2 (the folder you are reading from), that would be just bad practice. Always save it to another folder.
I hope this helps someone down the line.

using System;
using System.IO;

namespace ConsoleApplication4
{
    class Program
    {
        public static void Main(string[] args)
        {
            // Create a header for your text file
            string[] HeaderA = { "****** List of Files ******" };
            System.IO.File.WriteAllLines(@"c:\Folder1\ListOfFiles.txt", HeaderA);

            // Get all files from a folder and all its sub-folders. Here we are getting all files in the folder
            // named "Folder2" that is in "Folder1" on the C: drive. Notice the use of the 'forward and back slash'.
            string[] arrayA = Directory.GetFiles(@"c:\Folder1/Folder2", "*.*", SearchOption.AllDirectories);
            {
                //Now that we have a list of files, write them to a text file.
                WriteAllLines(@"c:\Folder1\ListOfFiles.txt", arrayA);
            }

            // Now, append the header and list to the text file.
            using (System.IO.StreamWriter file =
                new System.IO.StreamWriter(@"c:\Folder1\ListOfFiles.txt"))
            {
                // First - call the header 
                foreach (string line in HeaderA)
                {
                    file.WriteLine(line);
                }

                file.WriteLine(); // This line just puts a blank space between the header and list of files. 


                // Now, call teh list of files.
                foreach (string name in arrayA)
                {
                    file.WriteLine(name);
                }

            }
          }


        // These are just the "throw new exception" calls that are needed when converting the array's to strings. 

        // This one is for the Header.
        private static void WriteAllLines(string v, string file)
        {
            //throw new NotImplementedException();
        }

        // And this one is for the list of files. 
        private static void WriteAllLines(string v, string[] arrayA)
        {
            //throw new NotImplementedException();
        }



    }
}

How can I pass parameters to a partial view in mvc 4

For Asp.Net core you better use

<partial name="_MyPartialView" model="MyModel" />

So for example

@foreach (var item in Model)
{
   <partial name="_MyItemView" model="item" />
}

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

I have done a little plugin to show a iframe window to preview a link. Still in beta version. Maybe it fits your case: https://github.com/Fischer-L/previewbox.

using favicon with css

You can't set a favicon from CSS - if you want to do this explicitly you have to do it in the markup as you described.

Most browsers will, however, look for a favicon.ico file on the root of the web site - so if you access http://example.com most browsers will look for http://example.com/favicon.ico automatically.

How long do browsers cache HTTP 301s?

To solve the issue for a localhost address I changed the port number the site ran under. This worked on Chrome version 73.0.3683.86.

Definition of a Balanced Tree

There's no difference between these two things. Think about it.

Let's take a simpler definition, "A positive number is even if it is zero or that number minus two is even." Does this say 8 is even if 6 is even? Or does this say 8 is even if 6, 4, 2, and 0 are even?

There's no difference. If it says 8 is even if 6 is even, it also says 6 is even if 4 is even. And thus it also says 4 is even if 2 is even. And thus it says 2 is even if 0 is even. So if it says 8 is even if 6 is even, it (indirectly) says 8 is even if 6, 4, 2, and 0 are even.

It's the same thing here. Any indirect sub-tree can be found by a chain of direct sub-trees. So even if it only applies directly to direct sub-trees, it still applies indirectly to all sub-trees (and thus all nodes).

How to convert string to XML using C#

// using System.Xml;

String rawXml =
      @"<root>
          <person firstname=""Riley"" lastname=""Scott"" />
          <person firstname=""Thomas"" lastname=""Scott"" />
      </root>";

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.LoadXml(rawXml);

I think this should work.

Oracle pl-sql escape character (for a " ' ")

To escape it, double the quotes:

INSERT INTO TABLE_A VALUES ( 'Alex''s Tea Factory' );

Converting pixels to dp

If you want Integer values then using Math.round() will round the float to the nearest integer.

public static int pxFromDp(final float dp) {
        return Math.round(dp * Resources.getSystem().getDisplayMetrics().density);
    }

Pretty printing JSON from Jackson 2.2's ObjectMapper

You can enable pretty-printing by setting the SerializationFeature.INDENT_OUTPUT on your ObjectMapper like so:

mapper.enable(SerializationFeature.INDENT_OUTPUT);

Remove last 3 characters of string or number in javascript

Remove last 3 characters of a string

var str = '1437203995000';
str = str.substring(0, str.length-3);
// '1437203995'

Remove last 3 digits of a number

var a = 1437203995000;
a = (a-(a%1000))/1000;
// a = 1437203995

How to change PHP version used by composer

Old question I know, but just to add some additional information:

  • WAMP is used only on Microsoft Windows Operating Systems.
  • Changing the version of PHP used through the left-click -> PHP -> Version menu changes the version used by Apache to server your site.
  • Changing the version of PHP used through the right-click -> Tools -> Change PHP CLI Version menu changes the version used by WAMP's PHP CLI.

Note: It is important to understand that the "PHP CLI Version" is used by WAMP's own internal PHP scripts. This "PHP CLI Version" has nothing to do with the version you wish to use for your scripts, Composer or anything else.

For your scripts to work with the version you require, you need to add it's path to the Users Environmental Path. You could add it to the Systems environmental Path but the Users Path is the recommended option.

From WAMP v3.1.2, it would display an error when it detect reference to a PHP path in the System or User Environmental Path. This was to stop confusion such as you were experiencing. Since v3.1.7 the display of this error can now be optionally displayed through a selection in the WampSettings menu.

As indicated in previous answers, adding an installed PHP path (such as "C:\wamp64\bin\php\php7.2.30") to the Users Environmental Path is the correct approach. PS: As the value of the Users Environmental Path is a string, all paths added must be separated with a semi-colon (;)

After experiencing the exact same problem (IE: Choosing which version of PHP I wanted Composer to use), I created a script which could easily and rapidly switch between PHP CLI Versions depending on what project I was working on.

The Windows batch script "WampServer-PHP-CLI-Version-Changer" can be found at https://github.com/custom-dev-tools/WampServer-PHP-CLI-Version-Changer

I hope this helps others.

Good luck.

Use <Image> with a local file

ES6 solution:

import DefaultImage from '../assets/image.png';

const DEFAULT_IMAGE = Image.resolveAssetSource(DefaultImage).uri;

and then:

<Image source={{uri: DEFAULT_IMAGE}} />

How can I create a "Please Wait, Loading..." animation using jQuery?

It is very simple.

HTML

<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">

<body>

  <div id="cover"> <span class="glyphicon glyphicon-refresh w3-spin preloader-Icon"></span>Please Wait, Loading…</div>

  <h1>Dom Loaded</h1>
</body>

CSS

#cover {
  position: fixed;
  height: 100%;
  width: 100%;
  top: 0;
  left: 0;
  background: #141526;
  z-index: 9999;
  font-size: 65px;
  text-align: center;
  padding-top: 200px;
  color: #fff;
  font-family:tahoma;
}

JS - JQuery

$(window).on('load', function () {
  $("#cover").fadeOut(1750);
});

Excel formula to get ranking position

Type this to B3, and then pull it to the rest of the rows:

=IF(C3=C2,B2,B2+COUNTIF($C$1:$C3,C2))

What it does is:

  • If my points equals the previous points, I have the same position.
  • Othewise count the players with the same score as the previous one, and add their numbers to the previous player's position.

Determine the line of code that causes a segmentation fault?

There are a number of tools available which help debugging segmentation faults and I would like to add my favorite tool to the list: Address Sanitizers (often abbreviated ASAN).

Modern¹ compilers come with the handy -fsanitize=address flag, adding some compile time and run time overhead which does more error checking.

According to the documentation these checks include catching segmentation faults by default. The advantage here is that you get a stack trace similar to gdb's output, but without running the program inside a debugger. An example:

int main() {
  volatile int *ptr = (int*)0;
  *ptr = 0;
}
$ gcc -g -fsanitize=address main.c
$ ./a.out
AddressSanitizer:DEADLYSIGNAL
=================================================================
==4848==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x5654348db1a0 bp 0x7ffc05e39240 sp 0x7ffc05e39230 T0)
==4848==The signal is caused by a WRITE memory access.
==4848==Hint: address points to the zero page.
    #0 0x5654348db19f in main /tmp/tmp.s3gwjqb8zT/main.c:3
    #1 0x7f0e5a052b6a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x26b6a)
    #2 0x5654348db099 in _start (/tmp/tmp.s3gwjqb8zT/a.out+0x1099)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /tmp/tmp.s3gwjqb8zT/main.c:3 in main
==4848==ABORTING

The output is slightly more complicated than what gdb would output but there are upsides:

  • There is no need to reproduce the problem to receive a stack trace. Simply enabling the flag during development is enough.

  • ASANs catch a lot more than just segmentation faults. Many out of bounds accesses will be caught even if that memory area was accessible to the process.


¹ That is Clang 3.1+ and GCC 4.8+.

Empty set literal?

It depends on if you want the literal for a comparison, or for assignment.

If you want to make an existing set empty, you can use the .clear() metod, especially if you want to avoid creating a new object. If you want to do a comparison, use set() or check if the length is 0.

example:

#create a new set    
a=set([1,2,3,'foo','bar'])
#or, using a literal:
a={1,2,3,'foo','bar'}

#create an empty set
a=set()
#or, use the clear method
a.clear()

#comparison to a new blank set
if a==set():
    #do something

#length-checking comparison
if len(a)==0:
    #do something

Regular Expression for alphanumeric and underscores

For those of you looking for unicode alphanumeric matching, you might want to do something like:

^[\p{L} \p{Nd}_]+$

Further reading at http://unicode.org/reports/tr18/ and at http://www.regular-expressions.info/unicode.html

How to encode Doctrine entities to JSON in Symfony 2.0 AJAX application?

To complete the answer: Symfony2 comes with a wrapper around json_encode: Symfony/Component/HttpFoundation/JsonResponse

Typical usage in your Controllers:

...
use Symfony\Component\HttpFoundation\JsonResponse;
...
public function acmeAction() {
...
return new JsonResponse($array);
}

How to select all checkboxes with jQuery?

$("#select_all").change(function () {

    $('input[type="checkbox"]').prop("checked", $(this).prop("checked"));

});  

How to ISO 8601 format a Date with Timezone Offset in JavaScript?

The below should work properly, and for all browsers (thanks to @MattJohnson for the tip)

_x000D_
_x000D_
Date.prototype.toIsoString = function() {_x000D_
    var tzo = -this.getTimezoneOffset(),_x000D_
        dif = tzo >= 0 ? '+' : '-',_x000D_
        pad = function(num) {_x000D_
            var norm = Math.floor(Math.abs(num));_x000D_
            return (norm < 10 ? '0' : '') + norm;_x000D_
        };_x000D_
    return this.getFullYear() +_x000D_
        '-' + pad(this.getMonth() + 1) +_x000D_
        '-' + pad(this.getDate()) +_x000D_
        'T' + pad(this.getHours()) +_x000D_
        ':' + pad(this.getMinutes()) +_x000D_
        ':' + pad(this.getSeconds()) +_x000D_
        dif + pad(tzo / 60) +_x000D_
        ':' + pad(tzo % 60);_x000D_
}_x000D_
_x000D_
var dt = new Date();_x000D_
console.log(dt.toIsoString());
_x000D_
_x000D_
_x000D_

How do I separate an integer into separate digits in an array in JavaScript?

You can get a list of string from your number, by converting it to a string, and then splitting it with an empty string. The result will be an array of strings, each containing a digit:

const num = 124124124
const strArr = `${num}`.split("")

OR to build on this, map each string digit and convert them to a Number:

const intArr = `${num}`.split("").map(x => Number(x))

Equivalent VB keyword for 'break'

Exit [construct], and intelisense will tell you which one(s) are valid in a particular place.

MessageBodyWriter not found for media type=application/json

You've to create empty constructor because JAX-RS initializes the classes... Your constructor must have no arguments:

@XmlRootElement
public class Student implements Serializable {

    public String first_name;
    public String last_name;

    public String getFirst_name() {
        return first_name;
    }

    public void setFirst_name(String first_name) {
        this.first_name = first_name;
    }

    public String getLast_name() {
        return last_name;
    }

    public void setLast_name(String last_name) {
        this.last_name = last_name;
    }

    public Student()
    {
        first_name = "Fahad";
        last_name = "Mullaji";
    }


 public Student()
    {
    }
}

Can I access a form in the controller?

Yes, you can access a form in the controller (as stated in the docs).

Except when your form is not defined in the controller scope and is defined in a child scope instead.

Basically, some angular directives, such as ng-if, ng-repeat or ng-include, will create an isolated child scope. So will any custom directives with a scope: {} property defined. Probably, your foundation components are also in your way.

I had the same problem when introducing a simple ng-if around the <form> tag.

See these for more info:

Note: I suggest you re-write your question. The answer to your question is yes but your problem is slightly different:

Can I access a form in a child scope from the controller?

To which the answer would simply be: no.

Loop over html table and get checked checkboxes (JQuery)

Use this instead:

$('#save').click(function () {
    $('#mytable').find('input[type="checkbox"]:checked') //...
});

Let me explain you what the selector does: input[type="checkbox"] means that this will match each <input /> with type attribute type equals to checkbox After that: :checked will match all checked checkboxes.

You can loop over these checkboxes with:

$('#save').click(function () {
    $('#mytable').find('input[type="checkbox"]:checked').each(function () {
       //this is the current checkbox
    });
});

Here is demo in JSFiddle.


And here is a demo which solves exactly your problem http://jsfiddle.net/DuE8K/1/.

$('#save').click(function () {
    $('#mytable').find('tr').each(function () {
        var row = $(this);
        if (row.find('input[type="checkbox"]').is(':checked') &&
            row.find('textarea').val().length <= 0) {
            alert('You must fill the text area!');
        }
    });
});

How to set ANDROID_HOME path in ubuntu?

In the terminal just type these 3 commands to set the ANDROID_HOME Variable :

$ export ANDROID_HOME=~/Android/Sdk 

/Android/Sdk is the location of Sdk, this might get change in your case

$ PATH=$PATH:$ANDROID_HOME/tools
$ PATH=$PATH:$ANDROID_HOME/platform-tools `   

Note : This will set the path temporarily so what ever action you have to perform, perform on the same terminal.

What is the difference between max-device-width and max-width for mobile web?

Don't use device-width/height anymore.

device-width, device-height and device-aspect-ratio are deprecated in Media Queries Level 4: https://developer.mozilla.org/en-US/docs/Web/CSS/@media#Media_features

Just use width/height (without min/max) in combination with orientation & (min/max-)resolution to target specific devices. On mobile width/height should be the same as device-width/height.

SQL Server using wildcard within IN

As Jeremy Smith posted it, i'll recap, since I couldn't answer to that particular question of his.

select *
from jobdetails
where job_no like '071[1-2]%'

If you just need 0711% and 0712% you can also place a ranges within the brackets. For the NOT keyword you could also use [^1-2]%

Passing ArrayList from servlet to JSP

public class myActorServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;
    private String name;
    private String user;
    private String pass;
    private String given_table;
    private String tid;
    private String firstname;
    private String lastname;
    private String action;

    @Override
    public void doPost(HttpServletRequest request,
            HttpServletResponse response)
            throws IOException, ServletException {

        response.setContentType("text/html");

        // connecting to database
        Connection con = null;
        Statement stmt = null;
        ResultSet rs = null;

        PrintWriter out = response.getWriter();
        name = request.getParameter("screenName");
        user = request.getParameter("username");
        pass = request.getParameter("password");
        tid = request.getParameter("tid");
        firstname = request.getParameter("firstname");
        lastname = request.getParameter("lastname");
        action = request.getParameter("action");
        given_table = request.getParameter("tableName");

        out.println("<html>");
        out.println("<head>");
        out.println("<title>Servlet JDBC</title>");
        out.println("<link rel=\"stylesheet\" type=\"text/css\" href=\"style.css\">");
        out.println("</head>");
        out.println("<body>");
        out.println("<h1>Hello, " + name + " </h1>");
        out.println("<h1>Servlet JDBC</h1>");

        /////////////////////////
        // init connection object
        String sqlSelect = "SELECT * FROM `" + given_table + "`";
        String sqlInsert = "INSERT INTO `" + given_table + "`(`firstName`, `lastName`) VALUES ('" + firstname + "', '" + lastname + "')";
        String sqlUpdate = "UPDATE `" + given_table + "` SET `firstName`='" + firstname + "',`lastName`='" + lastname + "' WHERE `id`=" + tid + "";
        String sqlDelete = "DELETE FROM `" + given_table + "` WHERE `id` = '" + tid + "'";

        //////////////////////////////////////////////////////////
        out.println(
                "<p>Reading Table Data...Pass to JSP File...Okay<p>");

        ArrayList<Actor> list = new ArrayList<Actor>();
        // connecting to database
        try {
            Class.forName("com.mysql.jdbc.Driver");
            con = DriverManager.getConnection("jdbc:mysql://localhost:3306/javabase", user, pass);
            stmt = con.createStatement();
            rs = stmt.executeQuery(sqlSelect);
            // displaying records

            while (rs.next()) {
                Actor actor = new Actor();
                actor.setId(rs.getInt("id"));
                actor.setLastname(rs.getString("lastname"));
                actor.setFirstname(rs.getString("firstname"));
                list.add(actor);
            }
            request.setAttribute("actors", list);
            RequestDispatcher view = request.getRequestDispatcher("myActors_1.jsp");
            view.forward(request, response);

        } catch (SQLException e) {
            throw new ServletException("Servlet Could not display records.", e);
        } catch (ClassNotFoundException e) {
            throw new ServletException("JDBC Driver not found.", e);
        } finally {
            try {
                if (rs != null) {
                    rs.close();
                    rs = null;
                }
                if (stmt != null) {
                    stmt.close();
                    stmt = null;
                }
                if (con != null) {
                    con.close();
                    con = null;
                }
            } catch (SQLException e) {
            }
        }
        out.println("</body></html>");

        out.close();
    }

}

List all column except for one in R

You can index and use a negative sign to drop the 3rd column:

data[,-3]

Or you can list only the first 2 columns:

data[,c("c1", "c2")]
data[,1:2]

Don't forget the comma and referencing data frames works like this: data[row,column]

Code signing is required for product type 'Application' in SDK 'iOS 10.0' - StickerPackExtension requires a development team error

Xcode Version 11.0:

I recently upgraded to Xcode Version 11.0.

Looks like Apple moved the Signing to a new tab from the original General tab.

  1. Navigate to the application
  2. Select "Signing & Capabilities"
  3. Click "Enable Development Signing"

enter image description here

How to set editable true/false EditText in Android programmatically?

Fetch the KeyListener value of EditText by editText.getKeyListener() and store in the KeyListener type variable, which will contain the Editable property value:

KeyListener variable;
variable = editText.getKeyListener(); 

Set the Editable property of EditText to false as:

 edittext.setKeyListener(null);

Now set Editable property of EditText to true as:

editText.setKeyListener(variable);  

Note: In XML the default Editable property of EditText should be true.

The application may be doing too much work on its main thread

I am not an expert, but I got this debug message when I wanted to send data from my android application to a web server. Though I used AsyncTask class and did the data transfer in background, for getting the result data back from server I used get() method of the AsyncTask class which makes the UI synchronous which means that your UI will be waiting for too long. So my advice is to make your app do every network oriented tasks on a separate thread.

Setting ANDROID_HOME enviromental variable on Mac OS X

Where the Android-SDK is installed depends on how you installed it.

  1. If you downloaded the SDK through their website and then dragged/dropped the Application to your Applications folder, it's most likely here:

    /Applications/ADT/sdk (as it is in your case).

  2. If you installed the SDK using Homebrew (brew cask install android-sdk), then it's located here:

    /usr/local/Caskroom/android-sdk/{YOUR_SDK_VERSION_NUMBER}

  3. If the SDK was installed automatically as part of Android Studio then it's located here:

    /Users/{YOUR_USER_NAME}/Library/Android/sdk

Once you know the location, open a terminal window and enter the following (changing out the path to the SDK to be however you installed it):

export ANDROID_HOME={YOUR_PATH}

Once you have this set, you need to add this to the PATH environment variable:

export PATH=$PATH:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools

Lastly apply these changes by re-sourcing .bash_profile:

source ~/.bash_profile

  1. Type - echo $ANDROID_HOME to check if the home is set.

echo $ANDROID_HOME

How to redirect a page using onclick event in php?

you are using onclick which is javascript event. there is two ways

Javascript

<input type="button" value="Home" class="homebutton" id="btnHome" 
onClick="window.location = 'http://google.com'" />

Or PHP

create another page as redirect.php and put

<?php header('location : google.com') ?>

and insert this link on any page within the same directory

<a href="redirect.php">google<a/>

hope this helps its simplest!!

Absolute vs relative URLs

For every system that support relative URI resolution, both relative and absolute URIs do serve the same goal: referencing. And they can be used interchangeably. So you could decide in each case differently. Technically, they provide the same referencing.

To be precise, with each relative URI there already is an absolute URI. And that's the base-URI that relative URI is resolved against. So a relative URI is actually a feature on top of absolute URIs.

And that's also why with relative URIs you can do more as with an absolute URI alone - this is especially important for static websites which otherwise couldn't be as flexible to maintain as compared to absolute URIs.

These positive effects of relative URI resolution can be exploited for dynamic web-application development as well. The inflexibility absolute URIs do introduce are also easier to cope up with, in a dynamic environment, so for some developers that are unsure about URI resolution and how to properly implement and manage it (not that it's always easy) do often opt into using absolute URIs in a dynamic part of a website as they can introduce other dynamic features (e.g. configuration variable containing the URI prefix) so to work around the inflexibility.

So what is the benefit then in using absolute URIs? Technically there ain't, but one I'd say: Relative URIs are more complex because they need to be resolved against the so called absolute base-URI. Even the resolution is strictly define since years, you might run over a client that has a mistake in URI resolution. As absolute URIs do not need any resolution, using absolute URIs have no risk to run into faulty client behaviour with relative URI resolution. So how high is that risk actually? Well, it's very rare. I only know about one Internet browser that had an issue with relative URI resolution. And that was not generally but only in a very (obscure) case.

Next to the HTTP client (browser) it's perhaps more complex for an author of hypertext documents or code as well. Here the absolute URI has the benefit that it is easier to test, as you can just enter it as-is into your browsers address bar. However, if it's not just your one-hour job, it's most often of more benefit to you to actually understand absolute and relative URI handling so that you can actually exploit the benefits of relative linking.

How to group subarrays by a column value?

Consume and cache the column value that you want to group by, then push the remaining data as a new subarray of the group you have created in the the result.

function array_group(array $data, $by_column)
{
    $result = [];
    foreach ($data as $item) {
        $column = $item[$by_column];
        unset($item[$by_column]);
        $result[$column][] = $item;
    }
    return $result;
}

UTF-8 byte[] to String

You could use the methods described in this question (especially since you start off with an InputStream): Read/convert an InputStream to a String

In particular, if you don't want to rely on external libraries, you can try this answer, which reads the InputStream via an InputStreamReader into a char[] buffer and appends it into a StringBuilder.

Encoding conversion in java

I would just like to add that if the String is originally encoded using the wrong encoding it might be impossible to change it to another encoding without errors. The question does not state that the conversion here is made from wrong encoding to correct encoding but I personally stumbled to this question just because of this situation so just a heads up for others as well.

This answer in other question gives an explanation why the conversion does not always yield correct results https://stackoverflow.com/a/2623793/4702806

How to give credentials in a batch script that copies files to a network location?

You can also map the share to a local drive as follows:

net use X: "\\servername\share" /user:morgan password

Eclipse HotKey: how to switch between tabs?

Custom KeyBinding sequence example : CTRL + TAB to switch between visilble Modules or Editors Forward direction using Eclipse RCP.

you press CTRL + TAB second time to open another editor and close previous editor using RCP Eclipse.

package rcp_demo.Toolbar;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.ui.IEditorReference;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.handlers.HandlerUtil;
import rcp_demo.Editor.EmployeeEditor;
import rcp_demo.Editor.EmployeeEditorInput;
import rcp_demo.Editor.ProductEditor;
import rcp_demo.Editor.ProductEditorInput;
import rcp_demo.Editor.UserEditor;
import rcp_demo.Editor.UserEditorInput;

public class Forward_Editor extends AbstractHandler{

    static String Editor_name;  //  Active Editor name store in Temporary 
    static int cnt;             //  close editor count this variable
    @Override
    public Object execute(ExecutionEvent event) throws ExecutionException {

        IWorkbenchWindow window = HandlerUtil.getActiveWorkbenchWindow(event);
        IWorkbenchPage page = window.getActivePage();

        UserEditorInput std_input = new UserEditorInput();
        EmployeeEditorInput emp_input=new EmployeeEditorInput();
        ProductEditorInput product_input=new ProductEditorInput();

        IEditorReference[] editors = page.getEditorReferences();

        //Blank Editor Window to execute..
        if(editors.length==0)
        {
            //First time close editor can open Student_Editor
            if(cnt==1 && Editor_name.equals("Student_Editor"))
            {
                try {
                    page.openEditor(emp_input, EmployeeEditor.Id);
                    cnt=1;
                    Editor_name=page.getActiveEditor().getTitle();
                    System.out.println("EMP>>Len:: "+editors.length+"..EDi::"+Editor_name);
                } catch (PartInitException e) {
                    e.printStackTrace();
                }       
            }
            //First time close editor can open Employee_Editor
            else if(cnt==1 && Editor_name.equals("Employee_Editor"))
            {
                try {
                    page.openEditor(product_input,ProductEditor.ID);
                    cnt=1;
                    Editor_name=page.getActiveEditor().getTitle();
                    System.out.println("PRO>>Len:: "+editors.length+"..EDi::"+Editor_name); 
                } catch (PartInitException e) {e.printStackTrace();
                }
            }
            //First time close editor can open Product_Editor
            else if(cnt==1 && Editor_name.equals("Product_Editor"))
            {
                try {
                    page.openEditor(std_input, UserEditor.ID);
                    System.out.println("student Editor open");
                    cnt=1;
                    Editor_name=page.getActiveEditor().getTitle();
                    System.out.println("Close::"+Editor_name);
                } catch (PartInitException e) {
                    e.printStackTrace();
                }
            }
            //First Time call // empty editors 
            else{
                try {
                    page.openEditor(std_input, UserEditor.ID);
                    System.out.println("student Editor open");
                    Editor_name=page.getActiveEditor().getTitle();
                } catch (PartInitException e) {
                    e.printStackTrace();
                }
            }
        }//End if condition

        //AvtiveEditor(Student_Editor) close to open Employee Editor
        else if(page.getActiveEditor().getTitle().equals("Student_Editor"))
        {
            try {
                //page.closeAllEditors(true);
                page.closeEditor(page.getActiveEditor(), true);
                page.openEditor(emp_input, EmployeeEditor.Id);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("EMP>>Len:: "+editors.length+"..EDi::"+Editor_name);
            } catch (PartInitException e) {
                e.printStackTrace();
            }
        }
        //AvtiveEditor(Employee_Editor) close to open Product Editor
        else if(page.getActiveEditor().getTitle().equals("Employee_Editor"))
        {
            try {
                page.closeAllEditors(true);
                page.openEditor(product_input,ProductEditor.ID);

                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("PRO>>Len:: "+editors.length+"..EDi::"+Editor_name);

            } catch (PartInitException e) {
                e.printStackTrace();
            }
        }
        //AvtiveEditor(Product_Editor) close to open Student Editor
        else if(page.getActiveEditor().getTitle().equals("Product_Editor"))
        {
            try {
                page.closeAllEditors(true);
                page.openEditor(std_input, UserEditor.ID);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("stud>>Len:: "+editors.length+"..EDi::"+Editor_name);
            } catch (PartInitException e) {
                e.printStackTrace();
            }
        }
        //by default open Student Editor
        else 
        {
            try {
                page.closeAllEditors(true);
                page.openEditor(std_input, UserEditor.ID);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("stud_else>>Len:: "+editors.length+"..EDi::"+Editor_name);
            } catch (PartInitException e) {
                e.printStackTrace();
            }
        }
        return null;
    }
}

>Custom KeyBinding sequence example : <kbd> SHIFT + TAB </kbd> to switch between visilble Modules or Editors **Backword** direction using Eclipse RCP.


package rcp_demo.Toolbar;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.ui.IEditorReference;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.handlers.HandlerUtil;
import rcp_demo.Editor.EmployeeEditor;
import rcp_demo.Editor.EmployeeEditorInput;
import rcp_demo.Editor.ProductEditor;
import rcp_demo.Editor.ProductEditorInput;
import rcp_demo.Editor.UserEditor;
import rcp_demo.Editor.UserEditorInput;

public class Backword_Editor extends AbstractHandler{

    static String Editor_name;   // Active Editor name store in Temporary 
    static int cnt;

    @Override
    public Object execute(ExecutionEvent event) throws ExecutionException {

        IWorkbenchWindow window = HandlerUtil.getActiveWorkbenchWindow(event);
        IWorkbenchPage page = window.getActivePage();
        //Three object create in EditorInput 
        UserEditorInput std_input = new UserEditorInput();
        EmployeeEditorInput emp_input=new EmployeeEditorInput();
        ProductEditorInput product_input=new ProductEditorInput();

        IEditorReference[] editors = page.getEditorReferences();
        System.out.println("Length : "+editors.length);

        if(editors.length==0)
        {
            //First time close editor can open Student_Editor
            if(cnt==1 && Editor_name.equals("Product_Editor"))
            {
                try {
                    page.openEditor(emp_input, EmployeeEditor.Id);
                    cnt=1;
                    Editor_name=page.getActiveEditor().getTitle();
                    System.out.println("EMP>>Len:: "+editors.length+"..EDi::"+Editor_name);
                } catch (PartInitException e) {
                    e.printStackTrace();
                }               
            }
            //First time close editor can open Employee_Editor
            else if(cnt==1 && Editor_name.equals("Employee_Editor"))
            {
                try {
                    page.openEditor(std_input, UserEditor.ID);
                    cnt=1;
                    Editor_name=page.getActiveEditor().getTitle();
                    System.out.println("Student>>Len:: "+editors.length+"..student::"+Editor_name);

                } catch (PartInitException e) {
                    e.printStackTrace();
                }
            }
            //First time close editor can open Product_Editor
            else if(cnt==1 && Editor_name.equals("Student_Editor"))
            {
                        try {
                            page.openEditor(product_input,ProductEditor.ID);
                            cnt=1;
                            Editor_name=page.getActiveEditor().getTitle();
                            System.out.println("PRO>>Len:: "+editors.length+"..EDi::"+Editor_name);

                        } catch (PartInitException e) {
                            e.printStackTrace();
                        }
            } 
            //First Time or empty editors to check this condition
            else{
                try {
                    page.openEditor(product_input,ProductEditor.ID);
                    System.out.println("product Editor open");
                } catch (PartInitException e) {
                    e.printStackTrace();
                }
            }
        }
        //AvtiveEditor(Product_Editor) close to open Employee Editor
        else if(page.getActiveEditor().getTitle().equals("Product_Editor"))
        {
            System.out.println("Product:: "+page.getActiveEditor().getTitle());
            try {
                page.closeAllEditors(true);
                page.openEditor(emp_input, EmployeeEditor.Id);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("Employee Editor open");
            } catch (PartInitException e) {
                e.printStackTrace();
            }
        }
        //AvtiveEditor(Employee_Editor) close to open Student Editor
        else if(page.getActiveEditor().getTitle().equals("Employee_Editor"))
        {
            System.out.println("Emp:: "+page.getActiveEditor().getTitle());
            try {
                page.closeAllEditors(true);
                page.openEditor(std_input, UserEditor.ID);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("student Editor open");
            } catch (PartInitException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        //AvtiveEditor(Student_Editor) close to open Product Editor
        else if(page.getActiveEditor().getTitle().equals("Student_Editor"))
        {
            System.out.println("Product:: "+page.getActiveEditor().getTitle());
            try {
                page.closeAllEditors(true);
                page.openEditor(product_input,ProductEditor.ID);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("product Editor open");
            } catch (PartInitException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        //by default open Student Editor
        else 
        {
            try {
                page.closeAllEditors(true);
                page.openEditor(product_input,ProductEditor.ID);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("product Editor open");
            } catch (PartInitException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return null;
    }
}

Custom KeyBinding sequence example : SHIFT + TAB to switch between visilble Modules or Editors Backword direction using Eclipse RCP.

package rcp_demo.Toolbar;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.ui.IEditorReference;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.handlers.HandlerUtil;
import rcp_demo.Editor.EmployeeEditor;
import rcp_demo.Editor.EmployeeEditorInput;
import rcp_demo.Editor.ProductEditor;
import rcp_demo.Editor.ProductEditorInput;
import rcp_demo.Editor.UserEditor;
import rcp_demo.Editor.UserEditorInput;

public class Backword_Editor extends AbstractHandler{

    static String Editor_name;   // Active Editor name store in Temporary 
    static int cnt;

    @Override
    public Object execute(ExecutionEvent event) throws ExecutionException {

        IWorkbenchWindow window = HandlerUtil.getActiveWorkbenchWindow(event);
        IWorkbenchPage page = window.getActivePage();
        //Three object create in EditorInput 
        UserEditorInput std_input = new UserEditorInput();
        EmployeeEditorInput emp_input=new EmployeeEditorInput();
        ProductEditorInput product_input=new ProductEditorInput();

        IEditorReference[] editors = page.getEditorReferences();
        System.out.println("Length : "+editors.length);

        if(editors.length==0)
        {
            //First time close editor can open Student_Editor
            if(cnt==1 && Editor_name.equals("Product_Editor"))
            {
                try {
                    page.openEditor(emp_input, EmployeeEditor.Id);
                    cnt=1;
                    Editor_name=page.getActiveEditor().getTitle();
                    System.out.println("EMP>>Len:: "+editors.length+"..EDi::"+Editor_name);
                } catch (PartInitException e) {
                    e.printStackTrace();
                }               
            }
            //First time close editor can open Employee_Editor
            else if(cnt==1 && Editor_name.equals("Employee_Editor"))
            {
                try {
                    page.openEditor(std_input, UserEditor.ID);
                    cnt=1;
                    Editor_name=page.getActiveEditor().getTitle();
                    System.out.println("Student>>Len:: "+editors.length+"..student::"+Editor_name);

                } catch (PartInitException e) {
                    e.printStackTrace();
                }
            }
            //First time close editor can open Product_Editor
            else if(cnt==1 && Editor_name.equals("Student_Editor"))
            {
                        try {
                            page.openEditor(product_input,ProductEditor.ID);
                            cnt=1;
                            Editor_name=page.getActiveEditor().getTitle();
                            System.out.println("PRO>>Len:: "+editors.length+"..EDi::"+Editor_name);

                        } catch (PartInitException e) {
                            e.printStackTrace();
                        }
            } 
            //First Time or empty editors to check this condition
            else{
                try {
                    page.openEditor(product_input,ProductEditor.ID);
                    System.out.println("product Editor open");
                } catch (PartInitException e) {
                    e.printStackTrace();
                }
            }
        }
        //AvtiveEditor(Product_Editor) close to open Employee Editor
        else if(page.getActiveEditor().getTitle().equals("Product_Editor"))
        {
            System.out.println("Product:: "+page.getActiveEditor().getTitle());
            try {
                page.closeAllEditors(true);
                page.openEditor(emp_input, EmployeeEditor.Id);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("Employee Editor open");
            } catch (PartInitException e) {
                e.printStackTrace();
            }
        }
        //AvtiveEditor(Employee_Editor) close to open Student Editor
        else if(page.getActiveEditor().getTitle().equals("Employee_Editor"))
        {
            System.out.println("Emp:: "+page.getActiveEditor().getTitle());
            try {
                page.closeAllEditors(true);
                page.openEditor(std_input, UserEditor.ID);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("student Editor open");
            } catch (PartInitException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        //AvtiveEditor(Student_Editor) close to open Product Editor
        else if(page.getActiveEditor().getTitle().equals("Student_Editor"))
        {
            System.out.println("Product:: "+page.getActiveEditor().getTitle());
            try {
                page.closeAllEditors(true);
                page.openEditor(product_input,ProductEditor.ID);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("product Editor open");
            } catch (PartInitException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        //by default open Student Editor
        else 
        {
            try {
                page.closeAllEditors(true);
                page.openEditor(product_input,ProductEditor.ID);
                cnt=1;
                Editor_name=page.getActiveEditor().getTitle();
                System.out.println("product Editor open");
            } catch (PartInitException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return null;
    }
}

Key Sequence

M1 means CTRL

M2 means SHIFT

plugin.xml


<extension point="org.eclipse.ui.commands">
        <command
                defaultHandler="rcp_demo.Toolbar.Forward_Editor"
                id="RCP_Demo.Toolbar.Forward_editor_open_cmd"
                name="Forward_Editor">
        </command>
        <command
                defaultHandler="rcp_demo.Toolbar.Backword_Editor"
                id="RCP_Demo.Toolbar.backwards_editor_open_cmd"
                name="Backword_Editor">
        </command>
    </extension>
<extension point="org.eclipse.ui.bindings">
        <key
                commandId="RCP_Demo.Toolbar.Forward_editor_open_cmd"
                schemeId="org.eclipse.ui.defaultAcceleratorConfiguration"
                sequence="M1+TAB">
        </key>  
        <key
                commandId="RCP_Demo.Toolbar.backwards_editor_open_cmd"
                schemeId="org.eclipse.ui.defaultAcceleratorConfiguration"
                sequence="M2+TAB">
        </key>              
</extension>

Jackson overcoming underscores in favor of camel-case

If its a spring boot application, In application.properties file, just use

spring.jackson.property-naming-strategy=SNAKE_CASE

Or Annotate the model class with this annotation.

@JsonNaming(PropertyNamingStrategy.SnakeCaseStrategy.class)

adb remount permission denied, but able to access super user in shell -- android

I rebooted to recovery then

adb root; adb adb remount system; 

worked for me my recovery is twrp v3.5

How do I quickly rename a MySQL database (change schema name)?

When you rename a database in PHPMyAdmin it creates a dump, then drops and recreates the database with the new name.

Python functions call by reference

OK, I'll take a stab at this. Python passes by object reference, which is different from what you'd normally think of as "by reference" or "by value". Take this example:

def foo(x):
    print x

bar = 'some value'
foo(bar)

So you're creating a string object with value 'some value' and "binding" it to a variable named bar. In C, that would be similar to bar being a pointer to 'some value'.

When you call foo(bar), you're not passing in bar itself. You're passing in bar's value: a pointer to 'some value'. At that point, there are two "pointers" to the same string object.

Now compare that to:

def foo(x):
    x = 'another value'
    print x

bar = 'some value'
foo(bar)

Here's where the difference lies. In the line:

x = 'another value'

you're not actually altering the contents of x. In fact, that's not even possible. Instead, you're creating a new string object with value 'another value'. That assignment operator? It isn't saying "overwrite the thing x is pointing at with the new value". It's saying "update x to point at the new object instead". After that line, there are two string objects: 'some value' (with bar pointing at it) and 'another value' (with x pointing at it).

This isn't clumsy. When you understand how it works, it's a beautifully elegant, efficient system.

Are there any worse sorting algorithms than Bogosort (a.k.a Monkey Sort)?

Jingle Sort, as described here.

You give each value in your list to a different child on Christmas. Children, being awful human beings, will compare the value of their gifts and sort themselves accordingly.

Could not find folder 'tools' inside SDK

In my case i was using Ubuntu. Where the was two directories one was /android-sdks and /android-sdk-linux. I used the second one it works for me :)

Is there a color code for transparent in HTML?

Here, instead of making navigation bar transparent, remove any color attributes from the navigation bar to make the background visible.

Strangely, I came across this thinking that I needed a transparent color, but all I needed is to remove the color attributes.

.some-class{
    background-color: #fafafa; 
}

to

.some-class{
}

XmlDocument - load from string?

XmlDocument doc = new XmlDocument();
doc.LoadXml(str);

Where str is your XML string. See the MSDN article for more info.

ERROR 1064 (42000) in MySQL

Making the following changes in query solved this issue:

INSERT INTO table_name (`column1`, `column2`) values ('val1', 'val2');

Note that the column names are enclosed in ` (character above tab) and not in quotes.

OpenCV Error: (-215)size.width>0 && size.height>0 in function imshow

I have also met this issue. In my case, the image path is wrong, so the img read is NoneType. After I correct the image path, I can show it without any issue.

I want to delete all bin and obj folders to force all projects to rebuild everything

For the solution in batch. I am using the following command:

FOR /D /R %%G in (obj,bin) DO @IF EXIST %%G IF %%~aG geq d RMDIR /S /Q "%%G"


The reason not using DIR /S /AD /B xxx
1. DIR /S /AD /B obj will return empty list (at least on my Windows10) enter image description here
2. DIR /S /AD /B *obj will contain the result which is not expected (tobj folder) enter image description here

How to add "required" attribute to mvc razor viewmodel text input editor

On your model class decorate that property with [Required] attribute. I.e.:

[Required]
public string ShortName {get; set;}

How get data from material-ui TextField, DropDownMenu components?

flson's code did not work for me. For those in the similar situation, here is my slightly different code:

<TextField ref='myTextField'/>

get its value using

this.refs.myTextField.input.value

PHP not displaying errors even though display_errors = On

Check the error_reporting flag, must be E_ALL, but in some release of Plesk there are quotes ("E_ALL") instead of (E_ALL)

I solved this issue deleting the quotes (") in php.ini

from this:

error_reporting = "E_ALL"

to this:

error_reporting = E_ALL

Java String new line

System.out.println("I\nam\na\nboy");

This works It will give one space character also along before enter character

Git: "please tell me who you are" error

In my case I was missing "e" on the word "email" as Chad stated above but I see its not the case with you. Please hit the following command to see if everything is pulling as expected.

git config -l

How to Get a Sublist in C#

Reverse the items in a sub-list

int[] l = {0, 1, 2, 3, 4, 5, 6};
var res = new List<int>();
res.AddRange(l.Where((n, i) => i < 2));
res.AddRange(l.Where((n, i) => i >= 2 && i <= 4).Reverse());
res.AddRange(l.Where((n, i) => i > 4));

Gives 0,1,4,3,2,5,6

How to use the addr2line command in Linux?

Try adding the -f option to show the function names :

addr2line -f -e a.out 0x4005BDC

jQuery changing style of HTML element

Use this:

$('#navigation ul li').css('display', 'inline-block');

Also, as others have stated, if you want to make multiple css changes at once, that's when you would add the curly braces (for object notation), and it would look something like this (if you wanted to change, say, 'background-color' and 'position' in addition to 'display'):

$('#navigation ul li').css({'display': 'inline-block', 'background-color': '#fff', 'position': 'relative'}); //The specific CSS changes after the first one, are, of course, just examples.

installing cPickle with python 3.5

cPickle comes with the standard library… in python 2.x. You are on python 3.x, so if you want cPickle, you can do this:

>>> import _pickle as cPickle

However, in 3.x, it's easier just to use pickle.

No need to install anything. If something requires cPickle in python 3.x, then that's probably a bug.

java.sql.SQLException Parameter index out of range (1 > number of parameters, which is 0)

You will get this error when you call any of the setXxx() methods on PreparedStatement, while the SQL query string does not have any placeholders ? for this.

For example this is wrong:

String sql = "INSERT INTO tablename (col1, col2, col3) VALUES (val1, val2, val3)";
// ...

preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1, val1); // Fail.
preparedStatement.setString(2, val2);
preparedStatement.setString(3, val3);

You need to fix the SQL query string accordingly to specify the placeholders.

String sql = "INSERT INTO tablename (col1, col2, col3) VALUES (?, ?, ?)";
// ...

preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1, val1);
preparedStatement.setString(2, val2);
preparedStatement.setString(3, val3);

Note the parameter index starts with 1 and that you do not need to quote those placeholders like so:

String sql = "INSERT INTO tablename (col1, col2, col3) VALUES ('?', '?', '?')";

Otherwise you will still get the same exception, because the SQL parser will then interpret them as the actual string values and thus can't find the placeholders anymore.

See also:

Array copy values to keys in PHP

Be careful, the solution proposed with $a = array_combine($a, $a); will not work for numeric values.

I for example wanted to have a memory array(128,256,512,1024,2048,4096,8192,16384) to be the keys as well as the values however PHP manual states:

If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays contain numeric keys, the later value will not overwrite the original value, but will be appended.

So I solved it like this:

foreach($array as $key => $val) {
    $new_array[$val]=$val;
}

Make Bootstrap Popover Appear/Disappear on Hover instead of Click

After trying a few of these answers and finding they don't scale well with multiple links (for example the accepted answer requires a line of jquery for every link you have), I came across a way that requires minimal code to get working, and it also appears to work perfectly, at least on Chrome.

You add this line to activate it:

$('[data-toggle="popover"]').popover();

And these settings to your anchor links:

data-toggle="popover" data-trigger="hover"

See it in action here, I'm using the same imports as the accepted answer so it should work fine on older projects.

Plotting a python dict in order of key values

Simply pass the sorted items from the dictionary to the plot() function. concentration.items() returns a list of tuples where each tuple contains a key from the dictionary and its corresponding value.

You can take advantage of list unpacking (with *) to pass the sorted data directly to zip, and then again to pass it into plot():

import matplotlib.pyplot as plt

concentration = {
    0: 0.19849878712984576,
    5000: 0.093917341754771386,
    10000: 0.075060643507712022,
    20000: 0.06673074282575861,
    30000: 0.057119318961966224,
    50000: 0.046134834546203485,
    100000: 0.032495766396631424,
    200000: 0.018536317451599615,
    500000: 0.0059499290585381479}

plt.plot(*zip(*sorted(concentration.items())))
plt.show()

sorted() sorts tuples in the order of the tuple's items so you don't need to specify a key function because the tuples returned by dict.item() already begin with the key value.

Loop through JSON in EJS

JSON.stringify(data).length return string length not Object length, you can use Object.keys.

<% for(var i=0; i < Object.keys(data).length ; i++) {%>

https://stackoverflow.com/a/14379528/3224296

How do I generate a stream from a string?

public Stream GenerateStreamFromString(string s)
{
    return new MemoryStream(Encoding.UTF8.GetBytes(s));
}

Correct way to write line to file?

This should be as simple as:

with open('somefile.txt', 'a') as the_file:
    the_file.write('Hello\n')

From The Documentation:

Do not use os.linesep as a line terminator when writing files opened in text mode (the default); use a single '\n' instead, on all platforms.

Some useful reading:

How to set cookie in node js using express framework?

Set Cookie?

res.cookie('cookieName', 'cookieValue')

Read Cookie?

req.cookies

Demo

const express('express')
    , cookieParser = require('cookie-parser'); // in order to read cookie sent from client

app.get('/', (req,res)=>{

    // read cookies
    console.log(req.cookies) 

    let options = {
        maxAge: 1000 * 60 * 15, // would expire after 15 minutes
        httpOnly: true, // The cookie only accessible by the web server
        signed: true // Indicates if the cookie should be signed
    }

    // Set cookie
    res.cookie('cookieName', 'cookieValue', options) // options is optional
    res.send('')

})

python 3.2 UnicodeEncodeError: 'charmap' codec can't encode character '\u2013' in position 9629: character maps to <undefined>

Maybe a little late to reply. I happen to run into the same problem today. I find that on Windows you can change the console encoder to utf-8 or other encoder that can represent your data. Then you can print it to sys.stdout.

First, run following code in the console:

chcp 65001
set PYTHONIOENCODING=utf-8

Then, start python do anything you want.

Minimum 6 characters regex expression

Something along the lines of this?

<asp:TextBox id="txtUsername" runat="server" />

<asp:RegularExpressionValidator
    id="RegularExpressionValidator1"
    runat="server"
    ErrorMessage="Field not valid!"
    ControlToValidate="txtUsername"
    ValidationExpression="[0-9a-zA-Z]{6,}" />

An error occurred while signing: SignTool.exe not found

I did have similar problem. For some reason under project properties -> Signing -> Sign ClickOnce manifests was enabled.

I unchecked it and the problem went away.

How to enable CORS in AngularJs

I encountered a similar problem like this, problem was with the backend . I was using node server(Express). I had a get request from the frontend(angular) as shown below

   onGetUser(){
        return this.http.get("http://localhost:3000/user").pipe(map(
            (response:Response)=>{
                const user =response.json();
                return user;
            }
        )) 
    }

But it gave the following errorThe error

This is the backend code written using express without the headers

app.get('/user',async(req,res)=>{
     const user=await getuser();
     res.send(user);
 })

After adding a header to the method problem was solved

app.get('/user',async(req,res)=>{
    res.header("Access-Control-Allow-Origin", "*");
    const user=await getuser();
    res.send(user);
})

You can get more details about Enabling CORS on Node JS

overlay opaque div over youtube iframe

Hmm... what's different this time? http://jsfiddle.net/fdsaP/2/

Renders in Chrome fine. Do you need it cross-browser? It really helps being specific.

EDIT: Youtube renders the object and embed with no explicit wmode set, meaning it defaults to "window" which means it overlays everything. You need to either:


a) Host the page that contains the object/embed code yourself and add wmode="transparent" param element to object and attribute to embed if you choose to serve both elements

b) Find a way for youtube to specify those.


SQLRecoverableException: I/O Exception: Connection reset

We experienced these errors intermittently after upgraded from 11g to 12c and our java was on 1.6.

The fix for us was to upgrade java and jdbc from 6 to 7

export JAVA_HOME='/usr/java1.7'

export CLASSPATH=/u01/app/oracle/product/12.1.0/dbhome_1/jdbc/libojdbc7.jar:$CLASSPATH 

Several days later, still intermittent connection resets.

We ended up removing all the java 7 above. Java 6 was fine. The problem was fixed by adding this to our user bash_profile.

Our groovy scripts that were experiencing the error were using /dev/random on our batch VM server. Below forced java and groovy to use /dev/urandom.

export JAVA_OPTS=" $JAVA_OPTS -Djava.security.egd=file:///dev/urandom "

angular.js ng-repeat li items with html content

It goes like ng-bind-html-unsafe="opt.text":

<div ng-app ng-controller="MyCtrl">
    <ul>
    <li ng-repeat=" opt in opts" ng-bind-html-unsafe="opt.text" >
        {{ opt.text }}
    </li>
    </ul>

    <p>{{opt}}</p>
</div>

http://jsfiddle.net/gFFBa/3/

Or you can define a function in scope:

 $scope.getContent = function(obj){
     return obj.value + " " + obj.text;
 }

And use it this way:

<li ng-repeat=" opt in opts" ng-bind-html-unsafe="getContent(opt)" >
     {{ opt.value }}
</li>

http://jsfiddle.net/gFFBa/4/

Note that you can not do it with an option tag: Can I use HTML tags in the options for select elements?

Angular 2 two way binding using ngModel is not working

import FormsModule in your AppModule to work with two way binding [(ngModel)] with your

Date difference in years using C#

It's unclear how you want to handle fractional years, but perhaps like this:

DateTime now = DateTime.Now;
DateTime origin = new DateTime(2007, 11, 3);
int calendar_years = now.Year - origin.Year;
int whole_years = calendar_years - ((now.AddYears(-calendar_years) >= origin)? 0: 1);
int another_method = calendar_years - ((now.Month - origin.Month) * 32 >= origin.Day - now.Day)? 0: 1);

Should I call Close() or Dispose() for stream objects?

For what it's worth, the source code for Stream.Close explains why there are two methods:

// Stream used to require that all cleanup logic went into Close(),
// which was thought up before we invented IDisposable.  However, we
// need to follow the IDisposable pattern so that users can write
// sensible subclasses without needing to inspect all their base
// classes, and without worrying about version brittleness, from a
// base class switching to the Dispose pattern.  We're moving
// Stream to the Dispose(bool) pattern - that's where all subclasses
// should put their cleanup now.

In short, Close is only there because it predates Dispose, and it can't be deleted for compatibility reasons.

How to share data between different threads In C# using AOP?

You can't beat the simplicity of a locked message queue. I say don't waste your time with anything more complex.

Read up on the lock statement.

lock

EDIT

Here is an example of the Microsoft Queue object wrapped so all actions against it are thread safe.

public class Queue<T>
{
    /// <summary>Used as a lock target to ensure thread safety.</summary>
    private readonly Locker _Locker = new Locker();

    private readonly System.Collections.Generic.Queue<T> _Queue = new System.Collections.Generic.Queue<T>();

    /// <summary></summary>
    public void Enqueue(T item)
    {
        lock (_Locker)
        {
            _Queue.Enqueue(item);
        }
    }

    /// <summary>Enqueues a collection of items into this queue.</summary>
    public virtual void EnqueueRange(IEnumerable<T> items)
    {
        lock (_Locker)
        {
            if (items == null)
            {
                return;
            }

            foreach (T item in items)
            {
                _Queue.Enqueue(item);
            }
        }
    }

    /// <summary></summary>
    public T Dequeue()
    {
        lock (_Locker)
        {
            return _Queue.Dequeue();
        }
    }

    /// <summary></summary>
    public void Clear()
    {
        lock (_Locker)
        {
            _Queue.Clear();
        }
    }

    /// <summary></summary>
    public Int32 Count
    {
        get
        {
            lock (_Locker)
            {
                return _Queue.Count;
            }
        }
    }

    /// <summary></summary>
    public Boolean TryDequeue(out T item)
    {
        lock (_Locker)
        {
            if (_Queue.Count > 0)
            {
                item = _Queue.Dequeue();
                return true;
            }
            else
            {
                item = default(T);
                return false;
            }
        }
    }
}

EDIT 2

I hope this example helps. Remember this is bare bones. Using these basic ideas you can safely harness the power of threads.

public class WorkState
{
    private readonly Object _Lock = new Object();
    private Int32 _State;

    public Int32 GetState()
    {
        lock (_Lock)
        {
            return _State;
        }
    }

    public void UpdateState()
    {
        lock (_Lock)
        {
            _State++;   
        }   
    }
}

public class Worker
{
    private readonly WorkState _State;
    private readonly Thread _Thread;
    private volatile Boolean _KeepWorking;

    public Worker(WorkState state)
    {
        _State = state;
        _Thread = new Thread(DoWork);
        _KeepWorking = true;                
    }

    public void DoWork()
    {
        while (_KeepWorking)
        {
            _State.UpdateState();                   
        }
    }

    public void StartWorking()
    {
        _Thread.Start();
    }

    public void StopWorking()
    {
        _KeepWorking = false;
    }
}



private void Execute()
{
    WorkState state = new WorkState();
    Worker worker = new Worker(state);

    worker.StartWorking();

    while (true)
    {
        if (state.GetState() > 100)
        {
            worker.StopWorking();
            break;
        }
    }                   
}

JPA: unidirectional many-to-one and cascading delete

If you are using hibernate as your JPA provider you can use the annotation @OnDelete. This annotation will add to the relation the trigger ON DELETE CASCADE, which delegates the deletion of the children to the database.

Example:

public class Parent {
   
        @Id
        private long id;

}


public class Child {
        
        @Id
        private long id;
  
        @ManyToOne
        @OnDelete(action = OnDeleteAction.CASCADE)
        private Parent parent;
}
     

With this solution a unidirectional relationship from the child to the parent is enough to automatically remove all children. This solution does not need any listeners etc. Also a JPQL query like DELETE FROM Parent WHERE id = 1 will remove the children.

How to convert the ^M linebreak to 'normal' linebreak in a file opened in vim?

use dos2unix utility if the file was created on windows, use mac2unix utility if the file was created on mac. :)

How do I make a WinForms app go Full Screen

A tested and simple solution

I've been looking for an answer for this question in SO and some other sites, but one gave an answer was very complex to me and some others answers simply doesn't work correctly, so after a lot code testing I solved this puzzle.

Note: I'm using Windows 8 and my taskbar isn't on auto-hide mode.

I discovered that setting the WindowState to Normal before performing any modifications will stop the error with the not covered taskbar.

The code

I created this class that have two methods, the first enters in the "full screen mode" and the second leaves the "full screen mode". So you just need to create an object of this class and pass the Form you want to set full screen as an argument to the EnterFullScreenMode method or to the LeaveFullScreenMode method:

class FullScreen
{
    public void EnterFullScreenMode(Form targetForm)
    {
        targetForm.WindowState = FormWindowState.Normal;
        targetForm.FormBorderStyle = FormBorderStyle.None;
        targetForm.WindowState = FormWindowState.Maximized;
    }

    public void LeaveFullScreenMode(Form targetForm)
    {
        targetForm.FormBorderStyle = System.Windows.Forms.FormBorderStyle.Sizable;
        targetForm.WindowState = FormWindowState.Normal;
    }
}

Usage example

    private void fullScreenToolStripMenuItem_Click(object sender, EventArgs e)
    {
        FullScreen fullScreen = new FullScreen();

        if (fullScreenMode == FullScreenMode.No)  // FullScreenMode is an enum
        {
            fullScreen.EnterFullScreenMode(this);
            fullScreenMode = FullScreenMode.Yes;
        }
        else
        {
            fullScreen.LeaveFullScreenMode(this);
            fullScreenMode = FullScreenMode.No;
        }
    }

I have placed this same answer on another question that I'm not sure if is a duplicate or not of this one. (Link to the other question: How to display a Windows Form in full screen on top of the taskbar?)

Prompt for user input in PowerShell

Using parameter binding is definitely the way to go here. Not only is it very quick to write (just add [Parameter(Mandatory=$true)] above your mandatory parameters), but it's also the only option that you won't hate yourself for later.

More below:

[Console]::ReadLine is explicitly forbidden by the FxCop rules for PowerShell. Why? Because it only works in PowerShell.exe, not PowerShell ISE, PowerGUI, etc.

Read-Host is, quite simply, bad form. Read-Host uncontrollably stops the script to prompt the user, which means that you can never have another script that includes the script that uses Read-Host.

You're trying to ask for parameters.

You should use the [Parameter(Mandatory=$true)] attribute, and correct typing, to ask for the parameters.

If you use this on a [SecureString], it will prompt for a password field. If you use this on a Credential type, ([Management.Automation.PSCredential]), the credentials dialog will pop up, if the parameter isn't there. A string will just become a plain old text box. If you add a HelpMessage to the parameter attribute (that is, [Parameter(Mandatory = $true, HelpMessage = 'New User Credentials')]) then it will become help text for the prompt.

How to convert View Model into JSON object in ASP.NET MVC?

I found it to be pretty nice to do it like this (usage in the view):

    @Html.HiddenJsonFor(m => m.TrackingTypes)

Here is the according helper method Extension class:

public static class DataHelpers
{
    public static MvcHtmlString HiddenJsonFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression)
    {
        return HiddenJsonFor(htmlHelper, expression, (IDictionary<string, object>) null);
    }

    public static MvcHtmlString HiddenJsonFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, object htmlAttributes)
    {
        return HiddenJsonFor(htmlHelper, expression, HtmlHelper.AnonymousObjectToHtmlAttributes(htmlAttributes));
    }

    public static MvcHtmlString HiddenJsonFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IDictionary<string, object> htmlAttributes)
    {
        var name = ExpressionHelper.GetExpressionText(expression);
        var metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);

        var tagBuilder = new TagBuilder("input");
        tagBuilder.MergeAttributes(htmlAttributes);
        tagBuilder.MergeAttribute("name", name);
        tagBuilder.MergeAttribute("type", "hidden");

        var json = JsonConvert.SerializeObject(metadata.Model);

        tagBuilder.MergeAttribute("value", json);

        return MvcHtmlString.Create(tagBuilder.ToString());
    }
}

It is not super-sofisticated, but it solves the problem of where to put it (in Controller or in view?) The answer is obviously: neither ;)

Python: Importing urllib.quote

If you need to handle both Python 2.x and 3.x you can catch the exception and load the alternative.

try:
    from urllib import quote  # Python 2.X
except ImportError:
    from urllib.parse import quote  # Python 3+

You could also use the python compatibility wrapper six to handle this.

from six.moves.urllib.parse import quote

Show Curl POST Request Headers? Is there a way to do this?

You can make you request headers by yourself using:

// open a socket connection on port 80
$fp = fsockopen($host, 80);

// send the request headers:
fputs($fp, "POST $path HTTP/1.1\r\n");
fputs($fp, "Host: $host\r\n");
fputs($fp, "Referer: $referer\r\n");
fputs($fp, "Content-type: application/x-www-form-urlencoded\r\n");
fputs($fp, "Content-length: ". strlen($data) ."\r\n");
fputs($fp, "Connection: close\r\n\r\n");
fputs($fp, $data);

$result = ''; 
while(!feof($fp)) {
    // receive the results of the request
    $result .= fgets($fp, 128);
}

// close the socket connection:
fclose($fp);

Like writen on how make request

Check whether a string contains a substring

Case Insensitive Substring Example

This is an extension of Eugene's answer, which converts the strings to lower case before checking for the substring:

if (index(lc($str), lc($substr)) != -1) {
    print "$str contains $substr\n";
} 

Bundle ID Suffix? What is it?

If you don't have a company, leave your name, it doesn't matter as long as both bundle id in info.plist file and the one you've submitted in iTunes Connect match.

In Bundle ID Suffix you should write full name of bundle ID.

Example:

Bundle ID suffix = thebestapp (NOT CORRECT!!!!)

Bundle ID suffix = com.awesomeapps.thebestapp (CORRECT!!)

The reason for this is explained in the Developer Portal:

The App ID string contains two parts separated by a period (.) — an App ID Prefix (your Team ID by default, e.g. ABCDE12345), and an App ID Suffix (a Bundle ID search string, e.g. com.mycompany.appname). [emphasis added]

So in this case the suffix is the full string com.awesomeapps.thebestapp.

How to install mod_ssl for Apache httpd?

I used:

sudo yum install mod24_ssl

and it worked in my Amazon Linux AMI.

Tooltip on image

I am set Tooltips On My Working Project That Is 100% Working

_x000D_
_x000D_
<!DOCTYPE html>_x000D_
<html>_x000D_
<style>_x000D_
.tooltip {_x000D_
  position: relative;_x000D_
  display: inline-block;_x000D_
  border-bottom: 1px dotted black;_x000D_
}_x000D_
_x000D_
.tooltip .tooltiptext {_x000D_
  visibility: hidden;_x000D_
  width: 120px;_x000D_
  background-color: black;_x000D_
  color: #fff;_x000D_
  text-align: center;_x000D_
  border-radius: 6px;_x000D_
  padding: 5px 0;_x000D_
_x000D_
  /* Position the tooltip */_x000D_
  position: absolute;_x000D_
  z-index: 1;_x000D_
}_x000D_
_x000D_
.tooltip:hover .tooltiptext {_x000D_
  visibility: visible;_x000D_
}_x000D_
.size_of_img{_x000D_
width:90px}_x000D_
</style>_x000D_
_x000D_
<body style="text-align:center;">_x000D_
_x000D_
<p>Move the mouse over the text below:</p>_x000D_
_x000D_
<div class="tooltip"><img class="size_of_img" src="https://babeltechreviews.com/wp-content/uploads/2018/07/rendition1.img_.jpg" alt="Image 1" /><span class="tooltiptext">grewon.pdf</span></div>_x000D_
_x000D_
<p>Note that the position of the tooltip text isn't very good. Check More Position <a href="https://www.w3schools.com/css/css_tooltip.asp">GO</a></p>_x000D_
_x000D_
</body>_x000D_
</html>
_x000D_
_x000D_
_x000D_

Cannot create cache directory .. or directory is not writable. Proceeding without cache in Laravel

I had a similar problem recently, and needed to change the permissions of my vendor folder

By running following commands :

  1. php artisan cache:clear
  2. chmod -R 777 storage vendor
  3. composer dump-autoload

I need to give all the permissions required to open and write vendor files to solve this issue

Run CRON job everyday at specific time

From cron manual http://man7.org/linux/man-pages/man5/crontab.5.html:

Lists are allowed. A list is a set of numbers (or ranges) separated by commas. Examples: "1,2,5,9", "0-4,8-12".

So in this case it would be:

30 10,14 * * *

sorting integers in order lowest to highest java

if array.sort doesn't have what your looking for you can try this:

package drawFramePackage;
import java.awt.geom.AffineTransform;
import java.util.ArrayList;
import java.util.ListIterator;
import java.util.Random;
public class QuicksortAlgorithm {
    ArrayList<AffineTransform> affs;
    ListIterator<AffineTransform> li;
    Integer count, count2;
    /**
     * @param args
     */
    public static void main(String[] args) {
        new QuicksortAlgorithm();
    }
    public QuicksortAlgorithm(){
        count = new Integer(0);
        count2 = new Integer(1);
        affs = new ArrayList<AffineTransform>();
        for (int i = 0; i <= 128; i++){
            affs.add(new AffineTransform(1, 0, 0, 1, new Random().nextInt(1024), 0));
        }
        affs = arrangeNumbers(affs);
        printNumbers();
    }
    public ArrayList<AffineTransform> arrangeNumbers(ArrayList<AffineTransform> list){
        while (list.size() > 1 && count != list.size() - 1){
            if (list.get(count2).getTranslateX() > list.get(count).getTranslateX()){
                list.add(count, list.get(count2));
                list.remove(count2 + 1);
            }
            if (count2 == list.size() - 1){
                count++;
                count2 = count + 1;
            }
            else{
            count2++;
            }
        }
        return list;
    }
    public void printNumbers(){
        li = affs.listIterator();
        while (li.hasNext()){
            System.out.println(li.next());
        }
    }
}

Git and nasty "error: cannot lock existing info/refs fatal"

This is how it works for me.

  1. look up the Apache DAV lock file on your server (e.g. /var/lock/apache2/DAVlock)
  2. delete it
  3. recreate it with write permissions for the webserver
  4. restart the webserver

Even faster alternative:

  1. look up the Apache DAV lock file on your server (e.g. /var/lock/apache2/DAVlock)
  2. Empty the file: cat /dev/null > /var/lock/apache2/DAVlock
  3. restart the webserver

How do I automatically update a timestamp in PostgreSQL

Using 'now()' as default value automatically generates time-stamp.

Create ArrayList from array

Another Java8 solution (I may have missed the answer among the large set. If so, my apologies). This creates an ArrayList (as opposed to a List) i.e. one can delete elements

package package org.something.util;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class Junk {

    static <T> ArrayList<T>  arrToArrayList(T[] arr){
        return Arrays.asList(arr)
            .stream()
            .collect(Collectors.toCollection(ArrayList::new));
    }

    public static void main(String[] args) {
        String[] sArr = new String[]{"Hello", "cruel", "world"};
        List<String> ret = arrToArrayList(sArr);
        // Verify one can remove an item and print list to verify so
        ret.remove(1);
        ret.stream()
            .forEach(System.out::println);
    }
}

Output is...
Hello
world

Looping through JSON with node.js

If you want to avoid blocking, which is only necessary for very large loops, then wrap the contents of your loop in a function called like this: process.nextTick(function(){<contents of loop>}), which will defer execution until the next tick, giving an opportunity for pending calls from other asynchronous functions to be processed.

How to get the mysql table columns data type?

Most answers are duplicates, it might be useful to group them. Basically two simple options have been proposed.

First option

The first option has 4 different aliases, some of which are quite short :

EXPLAIN db_name.table_name;
DESCRIBE db_name.table_name;
SHOW FIELDS FROM db_name.table_name;
SHOW COLUMNS FROM db_name.table_name;

(NB : as an alternative to db_name.table_name, one can use a second FROM : db_name FROM table_name).

This gives something like :

+------------------+--------------+------+-----+---------+-------+
| Field            | Type         | Null | Key | Default | Extra |
+------------------+--------------+------+-----+---------+-------+
| product_id       | int(11)      | NO   | PRI | NULL    |       |
| name             | varchar(255) | NO   | MUL | NULL    |       |
| description      | text         | NO   |     | NULL    |       |
| meta_title       | varchar(255) | NO   |     | NULL    |       |
+------------------+--------------+------+-----+---------+-------+

Second option

The second option is a bit longer :

SELECT
  COLUMN_NAME, DATA_TYPE 
FROM
  INFORMATION_SCHEMA.COLUMNS 
WHERE
  TABLE_SCHEMA = 'db_name'
AND
  TABLE_NAME = 'table_name';

It is also less talkative :

+------------------+-----------+
| column_name      | DATA_TYPE |
+------------------+-----------+
| product_id       | int       |
| name             | varchar   |
| description      | text      |
| meta_title       | varchar   |
+------------------+-----------+

It has the advantage of allowing selection per column, though, using AND COLUMN_NAME = 'column_name' (or like).

CSS override rules and specificity

The important needs to be inside the ;

td.rule2 div {     background-color: #ffff00 !important; } 

in fact i believe this should override it

td.rule2 { background-color: #ffff00 !important; } 

Is it possible to refresh a single UITableViewCell in a UITableView?

Swift:

func updateCell(path:Int){
    let indexPath = NSIndexPath(forRow: path, inSection: 1)

    tableView.beginUpdates()
    tableView.reloadRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Automatic) //try other animations
    tableView.endUpdates()
}

Run a mySQL query as a cron job?

I personally find it easier use MySQL event scheduler than cron.

Enable it with

SET GLOBAL event_scheduler = ON;

and create an event like this:

CREATE EVENT name_of_event
ON SCHEDULE EVERY 1 DAY
STARTS '2014-01-18 00:00:00'
DO
DELETE FROM tbl_message WHERE DATEDIFF( NOW( ) ,  timestamp ) >=7;

and that's it.

Read more about the syntax here and here is more general information about it.

How do I use InputFilter to limit characters in an EditText in Android?

It's Right, the best way to go about it to fix it in the XML Layout itself using:

<EditText
android:inputType="text"
android:digits="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" />

as rightly pointed by Florian Fröhlich, it works well for text views even.

<TextView
android:inputType="text"
android:digits="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" />

Just a word of caution, the characters mentioned in the android:digits will only be displayed, so just be careful not to miss any set of characters out :)

Password hash function for Excel VBA

Here is the MD5 code inserted in an Excel Module with the name "module_md5":

    Private Const BITS_TO_A_BYTE = 8
    Private Const BYTES_TO_A_WORD = 4
    Private Const BITS_TO_A_WORD = 32

    Private m_lOnBits(30)
    Private m_l2Power(30)

    Sub SetUpArrays()
        m_lOnBits(0) = CLng(1)
        m_lOnBits(1) = CLng(3)
        m_lOnBits(2) = CLng(7)
        m_lOnBits(3) = CLng(15)
        m_lOnBits(4) = CLng(31)
        m_lOnBits(5) = CLng(63)
        m_lOnBits(6) = CLng(127)
        m_lOnBits(7) = CLng(255)
        m_lOnBits(8) = CLng(511)
        m_lOnBits(9) = CLng(1023)
        m_lOnBits(10) = CLng(2047)
        m_lOnBits(11) = CLng(4095)
        m_lOnBits(12) = CLng(8191)
        m_lOnBits(13) = CLng(16383)
        m_lOnBits(14) = CLng(32767)
        m_lOnBits(15) = CLng(65535)
        m_lOnBits(16) = CLng(131071)
        m_lOnBits(17) = CLng(262143)
        m_lOnBits(18) = CLng(524287)
        m_lOnBits(19) = CLng(1048575)
        m_lOnBits(20) = CLng(2097151)
        m_lOnBits(21) = CLng(4194303)
        m_lOnBits(22) = CLng(8388607)
        m_lOnBits(23) = CLng(16777215)
        m_lOnBits(24) = CLng(33554431)
        m_lOnBits(25) = CLng(67108863)
        m_lOnBits(26) = CLng(134217727)
        m_lOnBits(27) = CLng(268435455)
        m_lOnBits(28) = CLng(536870911)
        m_lOnBits(29) = CLng(1073741823)
        m_lOnBits(30) = CLng(2147483647)

        m_l2Power(0) = CLng(1)
        m_l2Power(1) = CLng(2)
        m_l2Power(2) = CLng(4)
        m_l2Power(3) = CLng(8)
        m_l2Power(4) = CLng(16)
        m_l2Power(5) = CLng(32)
        m_l2Power(6) = CLng(64)
        m_l2Power(7) = CLng(128)
        m_l2Power(8) = CLng(256)
        m_l2Power(9) = CLng(512)
        m_l2Power(10) = CLng(1024)
        m_l2Power(11) = CLng(2048)
        m_l2Power(12) = CLng(4096)
        m_l2Power(13) = CLng(8192)
        m_l2Power(14) = CLng(16384)
        m_l2Power(15) = CLng(32768)
        m_l2Power(16) = CLng(65536)
        m_l2Power(17) = CLng(131072)
        m_l2Power(18) = CLng(262144)
        m_l2Power(19) = CLng(524288)
        m_l2Power(20) = CLng(1048576)
        m_l2Power(21) = CLng(2097152)
        m_l2Power(22) = CLng(4194304)
        m_l2Power(23) = CLng(8388608)
        m_l2Power(24) = CLng(16777216)
        m_l2Power(25) = CLng(33554432)
        m_l2Power(26) = CLng(67108864)
        m_l2Power(27) = CLng(134217728)
        m_l2Power(28) = CLng(268435456)
        m_l2Power(29) = CLng(536870912)
        m_l2Power(30) = CLng(1073741824)
    End Sub

    Private Function LShift(lValue, iShiftBits)
        If iShiftBits = 0 Then
            LShift = lValue
            Exit Function
        ElseIf iShiftBits = 31 Then
            If lValue And 1 Then
                LShift = &H80000000
            Else
                LShift = 0
            End If
            Exit Function
        ElseIf iShiftBits < 0 Or iShiftBits > 31 Then
            Err.Raise 6
        End If

        If (lValue And m_l2Power(31 - iShiftBits)) Then
            LShift = ((lValue And m_lOnBits(31 - (iShiftBits + 1))) * m_l2Power(iShiftBits)) Or &H80000000
        Else
            LShift = ((lValue And m_lOnBits(31 - iShiftBits)) * m_l2Power(iShiftBits))
        End If
    End Function

    Private Function RShift(lValue, iShiftBits)
        If iShiftBits = 0 Then
            RShift = lValue
            Exit Function
        ElseIf iShiftBits = 31 Then
            If lValue And &H80000000 Then
                RShift = 1
            Else
                RShift = 0
            End If
            Exit Function
        ElseIf iShiftBits < 0 Or iShiftBits > 31 Then
            Err.Raise 6
        End If

        RShift = (lValue And &H7FFFFFFE) \ m_l2Power(iShiftBits)

        If (lValue And &H80000000) Then
            RShift = (RShift Or (&H40000000 \ m_l2Power(iShiftBits - 1)))
        End If
    End Function

    Private Function RotateLeft(lValue, iShiftBits)
        RotateLeft = LShift(lValue, iShiftBits) Or RShift(lValue, (32 - iShiftBits))
    End Function

    Private Function AddUnsigned(lX, lY)
        Dim lX4
        Dim lY4
        Dim lX8
        Dim lY8
        Dim lResult

        lX8 = lX And &H80000000
        lY8 = lY And &H80000000
        lX4 = lX And &H40000000
        lY4 = lY And &H40000000

        lResult = (lX And &H3FFFFFFF) + (lY And &H3FFFFFFF)

        If lX4 And lY4 Then
            lResult = lResult Xor &H80000000 Xor lX8 Xor lY8
        ElseIf lX4 Or lY4 Then
            If lResult And &H40000000 Then
                lResult = lResult Xor &HC0000000 Xor lX8 Xor lY8
            Else
                lResult = lResult Xor &H40000000 Xor lX8 Xor lY8
            End If
        Else
            lResult = lResult Xor lX8 Xor lY8
        End If

        AddUnsigned = lResult
    End Function

    Private Function F(x, y, z)
        F = (x And y) Or ((Not x) And z)
    End Function

    Private Function G(x, y, z)
        G = (x And z) Or (y And (Not z))
    End Function

    Private Function H(x, y, z)
        H = (x Xor y Xor z)
    End Function

    Private Function I(x, y, z)
        I = (y Xor (x Or (Not z)))
    End Function

    Private Sub FF(a, b, c, d, x, s, ac)
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac))
        a = RotateLeft(a, s)
        a = AddUnsigned(a, b)
    End Sub

    Private Sub GG(a, b, c, d, x, s, ac)
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac))
        a = RotateLeft(a, s)
        a = AddUnsigned(a, b)
    End Sub

    Private Sub HH(a, b, c, d, x, s, ac)
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac))
        a = RotateLeft(a, s)
        a = AddUnsigned(a, b)
    End Sub

    Private Sub II(a, b, c, d, x, s, ac)
        a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac))
        a = RotateLeft(a, s)
        a = AddUnsigned(a, b)
    End Sub

    Private Function ConvertToWordArray(sMessage)
        Dim lMessageLength
        Dim lNumberOfWords
        Dim lWordArray()
        Dim lBytePosition
        Dim lByteCount
        Dim lWordCount

        Const MODULUS_BITS = 512
        Const CONGRUENT_BITS = 448

        lMessageLength = Len(sMessage)

        lNumberOfWords = (((lMessageLength + ((MODULUS_BITS - CONGRUENT_BITS) \ BITS_TO_A_BYTE)) \ (MODULUS_BITS \ BITS_TO_A_BYTE)) + 1) * (MODULUS_BITS \ BITS_TO_A_WORD)
        ReDim lWordArray(lNumberOfWords - 1)

        lBytePosition = 0
        lByteCount = 0
        Do Until lByteCount >= lMessageLength
            lWordCount = lByteCount \ BYTES_TO_A_WORD
            lBytePosition = (lByteCount Mod BYTES_TO_A_WORD) * BITS_TO_A_BYTE
            lWordArray(lWordCount) = lWordArray(lWordCount) Or LShift(Asc(Mid(sMessage, lByteCount + 1, 1)), lBytePosition)
            lByteCount = lByteCount + 1
        Loop

        lWordCount = lByteCount \ BYTES_TO_A_WORD
        lBytePosition = (lByteCount Mod BYTES_TO_A_WORD) * BITS_TO_A_BYTE

        lWordArray(lWordCount) = lWordArray(lWordCount) Or LShift(&H80, lBytePosition)

        lWordArray(lNumberOfWords - 2) = LShift(lMessageLength, 3)
        lWordArray(lNumberOfWords - 1) = RShift(lMessageLength, 29)

        ConvertToWordArray = lWordArray
    End Function

    Private Function WordToHex(lValue)
        Dim lByte
        Dim lCount

        For lCount = 0 To 3
            lByte = RShift(lValue, lCount * BITS_TO_A_BYTE) And m_lOnBits(BITS_TO_A_BYTE - 1)
            WordToHex = WordToHex & Right("0" & Hex(lByte), 2)
        Next
    End Function

    Public Function MD5(sMessage)

        module_md5.SetUpArrays

        Dim x
        Dim k
        Dim AA
        Dim BB
        Dim CC
        Dim DD
        Dim a
        Dim b
        Dim c
        Dim d

        Const S11 = 7
        Const S12 = 12
        Const S13 = 17
        Const S14 = 22
        Const S21 = 5
        Const S22 = 9
        Const S23 = 14
        Const S24 = 20
        Const S31 = 4
        Const S32 = 11
        Const S33 = 16
        Const S34 = 23
        Const S41 = 6
        Const S42 = 10
        Const S43 = 15
        Const S44 = 21

        x = ConvertToWordArray(sMessage)

        a = &H67452301
        b = &HEFCDAB89
        c = &H98BADCFE
        d = &H10325476

        For k = 0 To UBound(x) Step 16
            AA = a
            BB = b
            CC = c
            DD = d

            FF a, b, c, d, x(k + 0), S11, &HD76AA478
            FF d, a, b, c, x(k + 1), S12, &HE8C7B756
            FF c, d, a, b, x(k + 2), S13, &H242070DB
            FF b, c, d, a, x(k + 3), S14, &HC1BDCEEE
            FF a, b, c, d, x(k + 4), S11, &HF57C0FAF
            FF d, a, b, c, x(k + 5), S12, &H4787C62A
            FF c, d, a, b, x(k + 6), S13, &HA8304613
            FF b, c, d, a, x(k + 7), S14, &HFD469501
            FF a, b, c, d, x(k + 8), S11, &H698098D8
            FF d, a, b, c, x(k + 9), S12, &H8B44F7AF
            FF c, d, a, b, x(k + 10), S13, &HFFFF5BB1
            FF b, c, d, a, x(k + 11), S14, &H895CD7BE
            FF a, b, c, d, x(k + 12), S11, &H6B901122
            FF d, a, b, c, x(k + 13), S12, &HFD987193
            FF c, d, a, b, x(k + 14), S13, &HA679438E
            FF b, c, d, a, x(k + 15), S14, &H49B40821

            GG a, b, c, d, x(k + 1), S21, &HF61E2562
            GG d, a, b, c, x(k + 6), S22, &HC040B340
            GG c, d, a, b, x(k + 11), S23, &H265E5A51
            GG b, c, d, a, x(k + 0), S24, &HE9B6C7AA
            GG a, b, c, d, x(k + 5), S21, &HD62F105D
            GG d, a, b, c, x(k + 10), S22, &H2441453
            GG c, d, a, b, x(k + 15), S23, &HD8A1E681
            GG b, c, d, a, x(k + 4), S24, &HE7D3FBC8
            GG a, b, c, d, x(k + 9), S21, &H21E1CDE6
            GG d, a, b, c, x(k + 14), S22, &HC33707D6
            GG c, d, a, b, x(k + 3), S23, &HF4D50D87
            GG b, c, d, a, x(k + 8), S24, &H455A14ED
            GG a, b, c, d, x(k + 13), S21, &HA9E3E905
            GG d, a, b, c, x(k + 2), S22, &HFCEFA3F8
            GG c, d, a, b, x(k + 7), S23, &H676F02D9
            GG b, c, d, a, x(k + 12), S24, &H8D2A4C8A

            HH a, b, c, d, x(k + 5), S31, &HFFFA3942
            HH d, a, b, c, x(k + 8), S32, &H8771F681
            HH c, d, a, b, x(k + 11), S33, &H6D9D6122
            HH b, c, d, a, x(k + 14), S34, &HFDE5380C
            HH a, b, c, d, x(k + 1), S31, &HA4BEEA44
            HH d, a, b, c, x(k + 4), S32, &H4BDECFA9
            HH c, d, a, b, x(k + 7), S33, &HF6BB4B60
            HH b, c, d, a, x(k + 10), S34, &HBEBFBC70
            HH a, b, c, d, x(k + 13), S31, &H289B7EC6
            HH d, a, b, c, x(k + 0), S32, &HEAA127FA
            HH c, d, a, b, x(k + 3), S33, &HD4EF3085
            HH b, c, d, a, x(k + 6), S34, &H4881D05
            HH a, b, c, d, x(k + 9), S31, &HD9D4D039
            HH d, a, b, c, x(k + 12), S32, &HE6DB99E5
            HH c, d, a, b, x(k + 15), S33, &H1FA27CF8
            HH b, c, d, a, x(k + 2), S34, &HC4AC5665

            II a, b, c, d, x(k + 0), S41, &HF4292244
            II d, a, b, c, x(k + 7), S42, &H432AFF97
            II c, d, a, b, x(k + 14), S43, &HAB9423A7
            II b, c, d, a, x(k + 5), S44, &HFC93A039
            II a, b, c, d, x(k + 12), S41, &H655B59C3
            II d, a, b, c, x(k + 3), S42, &H8F0CCC92
            II c, d, a, b, x(k + 10), S43, &HFFEFF47D
            II b, c, d, a, x(k + 1), S44, &H85845DD1
            II a, b, c, d, x(k + 8), S41, &H6FA87E4F
            II d, a, b, c, x(k + 15), S42, &HFE2CE6E0
            II c, d, a, b, x(k + 6), S43, &HA3014314
            II b, c, d, a, x(k + 13), S44, &H4E0811A1
            II a, b, c, d, x(k + 4), S41, &HF7537E82
            II d, a, b, c, x(k + 11), S42, &HBD3AF235
            II c, d, a, b, x(k + 2), S43, &H2AD7D2BB
            II b, c, d, a, x(k + 9), S44, &HEB86D391

            a = AddUnsigned(a, AA)
            b = AddUnsigned(b, BB)
            c = AddUnsigned(c, CC)
            d = AddUnsigned(d, DD)
        Next

        MD5 = LCase(WordToHex(a) & WordToHex(b) & WordToHex(c) & WordToHex(d))
    End Function

How to install and run phpize

For PHP7 Users

7.1

sudo apt install php7.1-dev

7.2

sudo apt install php7.2-dev

7.3

sudo apt install php7.3-dev

7.4

sudo apt install php7.4-dev

If not sure about your PHP version, simply run command php -v

Move a view up only when the keyboard covers an input field

Awesome answers are already given but this is a different way to deal with this situation (using Swift 3x):

First of all call the following method in viewWillAppear()

func registerForKeyboardNotifications() {

NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWasShown), name: NSNotification.Name.UIKeyboardDidShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillBeHidden), name: NSNotification.Name.UIKeyboardWillHide, object: nil)

}

Now take one IBOutlet of UIView's top constraints of your UIViewcontroller like this: (here the UIView is the subview of UIScrollView that means you should have a UIScrollView for all your subViews)

@IBOutlet weak var loginViewTopConstraint: NSLayoutConstraint!

And an another variable like following and add a delegate i.e. UITextFieldDelegate:

var activeTextField = UITextField() //This is to keep the reference of UITextField currently active

After that here is the magical part just paste this below snippet:

func keyboardWasShown(_ notification: Notification) {

let keyboardInfo  = notification.userInfo as NSDictionary?

//print(keyboardInfo!)

let keyboardFrameEnd: NSValue? = (keyboardInfo?.value(forKey: UIKeyboardFrameEndUserInfoKey) as? NSValue)

let keyboardFrameEndRect: CGRect? = keyboardFrameEnd?.cgRectValue


if activeTextField.frame.origin.y + activeTextField.frame.size.height + 10 > (keyboardFrameEndRect?.origin.y)! {

    UIView.animate(withDuration: 0.3, delay: 0, options: .transitionFlipFromTop, animations: {() -> Void in

        //code with animation

        //Print some stuff to know what is actually happening
        //print(self.activeTextField.frame.origin.y)
        //print(self.activeTextField.frame.size.height)
        //print(self.activeTextField.frame.size.height)

        self.loginViewTopConstraint.constant = -(self.activeTextField.frame.origin.y + self.activeTextField.frame.size.height - (keyboardFrameEndRect?.origin.y)!) - 30.0

        self.view.layoutIfNeeded()

    }, completion: {(_ finished: Bool) -> Void in
        //code for completion

    })
}
}

func keyboardWillBeHidden(_ notification: Notification) {

UIView.animate(withDuration: 0.3, animations: {() -> Void in

    self.loginViewTopConstraint.constant = self.view.frame.origin.y
    self.view.layoutIfNeeded()

})
}

//MARK: textfield delegates
func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
    activeTextField = textField
    return true
}

func textFieldShouldReturn(_ textField: UITextField) -> Bool {

           switch textField {
    case YOUR_TEXTFIELD_ONE:
        YOUR_TEXTFIELD_TWO.becomeFirstResponder()
        break
    case YOUR_TEXTFIELD_TWO:
        YOUR_TEXTFIELD_THREE.becomeFirstResponder()
        break
    default:
        textField.resignFirstResponder()
        break
    }
    return true
}

Now the last snippet:

//Remove Keyboard Observers
override func viewWillDisappear(_ animated: Bool) {

NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardDidShow, object: nil)

NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}

Don't forget to assign delegates to all your UITextFields in UIStoryboard

Good luck!

How to get height of <div> in px dimension

There is a built-in method to get the bounding rectangle: Element.getBoundingClientRect.

The result is the smallest rectangle which contains the entire element, with the read-only left, top, right, bottom, x, y, width, and height properties.

See the example below:

_x000D_
_x000D_
let innerBox = document.getElementById("myDiv").getBoundingClientRect().height;_x000D_
document.getElementById("data_box").innerHTML = "height: " + innerBox;
_x000D_
body {_x000D_
  margin: 0;_x000D_
}_x000D_
_x000D_
.relative {_x000D_
  width: 220px;_x000D_
  height: 180px;_x000D_
  position: relative;_x000D_
  background-color: purple;_x000D_
}_x000D_
_x000D_
.absolute {_x000D_
  position: absolute;_x000D_
  top: 30px;_x000D_
  left: 20px;_x000D_
  background-color: orange;_x000D_
  padding: 30px;_x000D_
  overflow: hidden;_x000D_
}_x000D_
_x000D_
#myDiv {_x000D_
  margin: 20px;_x000D_
  padding: 10px;_x000D_
  color: red;_x000D_
  font-weight: bold;_x000D_
  background-color: yellow;_x000D_
}_x000D_
_x000D_
#data_box {_x000D_
  font: 30px arial, sans-serif;_x000D_
}
_x000D_
Get height of <mark>myDiv</mark> in px dimension:_x000D_
<div id="data_box"></div>_x000D_
<div class="relative">_x000D_
  <div class="absolute">_x000D_
    <div id="myDiv">myDiv</div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Scala vs. Groovy vs. Clojure

I never had time to play with clojure. But for scala vs groovy, this is words from James Strachan - Groovy creator

"Though my tip though for the long term replacement of javac is Scala. I'm very impressed with it! I can honestly say if someone had shown me the Programming in Scala book by Martin Odersky, Lex Spoon & Bill Venners back in 2003 I'd probably have never created Groovy."

You can read the whole story here

Python: Is there an equivalent of mid, right, and left from BASIC?

If I remember my QBasic, right, left and mid do something like this:

>>> s = '123456789'
>>> s[-2:]
'89'
>>> s[:2]
'12'
>>> s[4:6]
'56'

http://www.angelfire.com/scifi/nightcode/prglang/qbasic/function/strings/left_right.html

how to remove new lines and returns from php string?

Something a bit more functional (easy to use anywhere):

function replace_carriage_return($replace, $string)
{
    return str_replace(array("\n\r", "\n", "\r"), $replace, $string);
}

Using PHP_EOL as the search replacement parameter is also a good idea! Kudos.

Clip/Crop background-image with CSS

may be you can write like this:

#graphic { 
 background-image: url(image.jpg); 
 background-position: 0 -50px; 
 width: 200px; 
 height: 100px;
}

Turning off eslint rule for a specific file

/* eslint-disable */

//suppress all warnings between comments
alert('foo');

/* eslint-enable */

This will disable all eslint rules within the block.

How to create and add users to a group in Jenkins for authentication?

I installed the Role plugin under Jenkins-3.5, but it does not show the "Manage Roles" option under "Manage Jenkins", and when one follows the security install page from the wiki, all users are locked out instantly. I had to manually shutdown Jenkins on the server, restore the correct configuration settings (/me is happy to do proper backups) and restart Jenkins.

I didn't have high hopes, as that plugin was last updated in 2011

How to convert InputStream to FileInputStream

Long story short: Don't use FileInputStream as a parameter or variable type. Use the abstract base class, in this case InputStream instead.

Android/Java - Date Difference in days

This fragment accounts for daylight savings time and is O(1).

private final static long MILLISECS_PER_DAY = 24 * 60 * 60 * 1000;

private static long getDateToLong(Date date) {
    return Date.UTC(date.getYear(), date.getMonth(), date.getDate(), 0, 0, 0);
}

public static int getSignedDiffInDays(Date beginDate, Date endDate) {
    long beginMS = getDateToLong(beginDate);
    long endMS = getDateToLong(endDate);
    long diff = (endMS - beginMS) / (MILLISECS_PER_DAY);
    return (int)diff;
}

public static int getUnsignedDiffInDays(Date beginDate, Date endDate) {
    return Math.abs(getSignedDiffInDays(beginDate, endDate));
}

Unicode character for "X" cancel / close?

&times; and font-family: Garamond, "Apple Garamond"; make it good enough. Garamond font is thin and web safe

proper close X

Best Way to View Generated Source of Webpage?

This is an old question, and here's an old answer that has once worked flawlessly for me for many years, but doesn't any more, at least not as of January 2016:

The "Generated Source" bookmarklet from SquareFree does exactly what you want -- and, unlike the otherwise fine "old gold" from @Johnny5, displays as source code (rather than being rendered normally by the browser, at least in the case of Google Chrome on Mac):

https://www.squarefree.com/bookmarklets/webdevel.html#generated_source

Unfortunately, it behaves just like the "old gold" from @Johnny5: it does not show up as source code any more. Sorry.

Simple JavaScript login form validation

<form name="loginform" onsubmit="validateForm()">

instead of putting the onsubmit on the actual input button

How to pass multiple parameters in json format to a web service using jquery?

I think the best way is:

data: "{'Ids':['2','2']}"

To read this values Ids[0], Ids[1].

How to use sed to remove the last n lines of a file

To truncate very large files truly in-place we have truncate command. It doesn't know about lines, but tail + wc can convert lines to bytes:

file=bigone.log
lines=3
truncate -s -$(tail -$lines $file | wc -c) $file

There is an obvious race condition if the file is written at the same time. In this case it may be better to use head - it counts bytes from the beginning of file (mind disk IO), so we will always truncate on line boundary (possibly more lines than expected if file is actively written):

truncate -s $(head -n -$lines $file | wc -c) $file

Handy one-liner if you fail login attempt putting password in place of username:

truncate -s $(head -n -5 /var/log/secure | wc -c) /var/log/secure

How do I run Visual Studio as an administrator by default?

There are two ways to Run Visual Studio as Administrator:

1. Only 1 time: For this go to startup search bar, search for Visual studio 2017 or what ever version you have, then Right click on VS and Run as Administrator.

2. Permanent or Always: For this go to startup search bar, search for visual studio, right click to it and go to properties. In the properties click on advanced button and check the Run as Administrator check box and then click on ok.

"Port 4200 is already in use" when running the ng serve command

ng serve --port <YOUR_GIVEN_PORT_NUMBER>

You should try above command to run on your given port.

What's the difference between ".equals" and "=="?

The == operator compares if the objects are the same instance. The equals() oerator compares the state of the objects (e.g. if all attributes are equal). You can even override the equals() method to define yourself when an object is equal to another.

How to populate/instantiate a C# array with a single value?

What about a parallel implementation

public static void InitializeArray<T>(T[] array, T value)
{
    var cores = Environment.ProcessorCount;

    ArraySegment<T>[] segments = new ArraySegment<T>[cores];

    var step = array.Length / cores;
    for (int i = 0; i < cores; i++)
    {
        segments[i] = new ArraySegment<T>(array, i * step, step);
    }
    var remaining = array.Length % cores;
    if (remaining != 0)
    {
        var lastIndex = segments.Length - 1;
        segments[lastIndex] = new ArraySegment<T>(array, lastIndex * step, array.Length - (lastIndex * step));
    }

    var initializers = new Task[cores];
    for (int i = 0; i < cores; i++)
    {
        var index = i;
        var t = new Task(() =>
        {
            var s = segments[index];
            for (int j = 0; j < s.Count; j++)
            {
                array[j + s.Offset] = value;
            }
        });
        initializers[i] = t;
        t.Start();
    }

    Task.WaitAll(initializers);
}

When only initializing an array the power of this code can't be seen but I think you should definitely forget about the "pure" for.

How to quit a java app from within the program

System.exit(ABORT); Quit's the process immediately.

How to add not null constraint to existing column in MySQL

Just use an ALTER TABLE... MODIFY... query and add NOT NULL into your existing column definition. For example:

ALTER TABLE Person MODIFY P_Id INT(11) NOT NULL;

A word of caution: you need to specify the full column definition again when using a MODIFY query. If your column has, for example, a DEFAULT value, or a column comment, you need to specify it in the MODIFY statement along with the data type and the NOT NULL, or it will be lost. The safest practice to guard against such mishaps is to copy the column definition from the output of a SHOW CREATE TABLE YourTable query, modify it to include the NOT NULL constraint, and paste it into your ALTER TABLE... MODIFY... query.

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

None of the above methods worked for me so i'm posting the way i did

DELIMITER $$
CREATE PROCEDURE AddBrand()
BEGIN 

DECLARE BrandName varchar(50);
DECLARE CategoryID,BrandID  int;
SELECT BrandID = BrandID FROM tblBrand 
WHERE BrandName = BrandName;

INSERT INTO tblBrandinCategory (CategoryID, BrandID) 
       VALUES (CategoryID, BrandID);
END$$

Is it possible to create a 'link to a folder' in a SharePoint document library?

The simplest way is to use the following pattern:

http://[server]/[site]/[ListName]/[Folder]/[SubFolder]

To place a shortcut to a document library:

  1. Upload it as *.url file. However, by default, this file type is not allowed.
  2. Go to you Document Library settings > Advanced Settings > Allow management of content types. Add the "Link to document" content type to a document library and paste the link

fileReader.readAsBinaryString to upload files

(Following is a late but complete answer)

FileReader methods support


FileReader.readAsBinaryString() is deprecated. Don't use it! It's no longer in the W3C File API working draft:

void abort();
void readAsArrayBuffer(Blob blob);
void readAsText(Blob blob, optional DOMString encoding);
void readAsDataURL(Blob blob);

NB: Note that File is a kind of extended Blob structure.

Mozilla still implements readAsBinaryString() and describes it in MDN FileApi documentation:

void abort();
void readAsArrayBuffer(in Blob blob); Requires Gecko 7.0
void readAsBinaryString(in Blob blob);
void readAsDataURL(in Blob file);
void readAsText(in Blob blob, [optional] in DOMString encoding);

The reason behind readAsBinaryString() deprecation is in my opinion the following: the standard for JavaScript strings are DOMString which only accept UTF-8 characters, NOT random binary data. So don't use readAsBinaryString(), that's not safe and ECMAScript-compliant at all.

We know that JavaScript strings are not supposed to store binary data but Mozilla in some sort can. That's dangerous in my opinion. Blob and typed arrays (ArrayBuffer and the not-yet-implemented but not necessary StringView) were invented for one purpose: allow the use of pure binary data, without UTF-8 strings restrictions.

XMLHttpRequest upload support


XMLHttpRequest.send() has the following invocations options:

void send();
void send(ArrayBuffer data);
void send(Blob data);
void send(Document data);
void send(DOMString? data);
void send(FormData data);

XMLHttpRequest.sendAsBinary() has the following invocations options:

void sendAsBinary(   in DOMString body );

sendAsBinary() is NOT a standard and may not be supported in Chrome.

Solutions


So you have several options:

  1. send() the FileReader.result of FileReader.readAsArrayBuffer ( fileObject ). It is more complicated to manipulate (you'll have to make a separate send() for it) but it's the RECOMMENDED APPROACH.
  2. send() the FileReader.result of FileReader.readAsDataURL( fileObject ). It generates useless overhead and compression latency, requires a decompression step on the server-side BUT it's easy to manipulate as a string in Javascript.
  3. Being non-standard and sendAsBinary() the FileReader.result of FileReader.readAsBinaryString( fileObject )

MDN states that:

The best way to send binary content (like in files upload) is using ArrayBuffers or Blobs in conjuncton with the send() method. However, if you want to send a stringifiable raw data, use the sendAsBinary() method instead, or the StringView (Non native) typed arrays superclass.

How to select a radio button by default?

Add this attribute:

checked="checked"

jquery/javascript convert date string to date

I would grab date.js or else you will need to roll your own formatting function.

How to detect Adblock on my website?

I know this is already answered, but I looked at the suggested sample site, and I see they do it like this:

<script type="text/javascript">
if(document.getElementsByTagName("iframe").item(0) == null) {
    document.write("<div style="width: 160px; height: 600px; padding-top: 280px; margin-left: 5px; border: 1px solid #666666; color: #FFF; background-color: #666; text-align:center; font-family: Maven Pro, century gothic, arial, helvetica, sans-serif; padding-left: 5px; padding-right: 5px; border-radius: 7px; font-size: 18px;">Advertising seems to be blocked by your browser.<br><br><span style="font-size: 12px;">Please notice that advertising helps us to host the project.<br><br>If you find these ads intrusive or inappropriate, please contact me.</span><br><img src="http://www.playonlinux.com/images/abp.png" alt="Adblock Plus"></div>");
};
</script>

Back to previous page with header( "Location: " ); in PHP

Its so simple just use this

header("location:javascript://history.go(-1)");

Its working fine for me

PowerShell: Format-Table without headers

I know it's 2 years late, but these answers helped me to formulate a filter function to output objects and trim the resulting strings. Since I have to format everything into a string in my final solution I went about things a little differently. Long-hand, my problem is very similar, and looks a bit like this

$verbosepreference="Continue"
write-verbose (ls | ft | out-string) # this generated too many blank lines

Here is my example:

ls | Out-Verbose # out-verbose formats the (pipelined) object(s) and then trims blanks

My Out-Verbose function looks like this:

filter Out-Verbose{
Param([parameter(valuefrompipeline=$true)][PSObject[]]$InputObject,
      [scriptblock]$script={write-verbose "$_"})
  Begin {
    $val=@()
  }
  Process {
    $val += $inputobject
  }
  End {
    $val | ft -autosize -wrap|out-string |%{$_.split("`r`n")} |?{$_.length} |%{$script.Invoke()}
  }
}

Note1: This solution will not scale to like millions of objects(it does not handle the pipeline serially)

Note2: You can still add a -noheaddings option. If you are wondering why I used a scriptblock here, that's to allow overloading like to send to disk-file or other output streams.

HTML5 Video // Completely Hide Controls

There are two ways to hide video tag controls

  1. Remove the controls attribute from the video tag.

  2. Add the css to the video tag

    video::-webkit-media-controls-panel {
    display: none !important;
    opacity: 1 !important;}
    

Installing a dependency with Bower from URL and specify version

I believe that specifying version works only for git-endpoints. And not for folder/zip ones. As when you point bower to a js-file/folder/zip you already specified package and version (except for js indeed). Because a package has bower.json with version in it. Specifying a version in 'bower install' makes sense when you're pointing bower to a repository which can have many versions of a package. It can be only git I think.

How to capture the screenshot of a specific element rather than entire page using Selenium Webdriver?

Surya's answer works great if you don't mind involving disk IO. If you'd rather not, then this method may be better for you

private Image getScreenshot(final WebDriver d, final WebElement e) throws IOException {
    final BufferedImage img;
    final Point topleft;
    final Point bottomright;

    final byte[] screengrab;
    screengrab = ((TakesScreenshot) d).getScreenshotAs(OutputType.BYTES);

    img = ImageIO.read(new ByteArrayInputStream(screengrab));

    //crop the image to focus on e
    //get dimensions (crop points)
    topleft = e.getLocation();
    bottomright = new Point(e.getSize().getWidth(),
                            e.getSize().getHeight());

    return img.getSubimage(topleft.getX(),
                           topleft.getY(),
                           bottomright.getX(),
                           bottomright.getY());
}

If you prefer you can skip declaring screengrab and instead doing

img = ImageIO.read(
    new ByteArrayInputStream(
        ((TakesScreenshot) d).getScreenshotAs(OutputType.BYTES)));

which is cleaner, but I left it in for clarity. You can then save it as a file or put it in a JPanel to your heart's content.

Visual Studio 2012 Web Publish doesn't copy files

The following worked for me:

Simply change from Release>Debug>Release (or vice-versa) and then publish.

No need for deleting, editing, publishing anything you don't need to.

Querying date field in MongoDB with Mongoose

{ "date" : "1000000" } in your Mongo doc seems suspect. Since it's a number, it should be { date : 1000000 }

It's probably a type mismatch. Try post.findOne({date: "1000000"}, callback) and if that works, you have a typing issue.

Debugging in Maven?

If you are using Netbeans, there is a nice shortcut to this. Just define a goal exec:java and add the property jpda.listen=maven Netbeans screenshot

Tested on Netbeans 7.3

How can I use std::maps with user-defined types as key?

You need to define operator < for the Class1.

Map needs to compare the values using operator < and hence you need to provide the same when user defined class are used as key.

class Class1
{
public:
    Class1(int id);

    bool operator <(const Class1& rhs) const
    {
        return id < rhs.id;
    }
private:
    int id;
};

Why can't overriding methods throw exceptions broader than the overridden method?

I provide this answer here to the old question since no answers tell the fact that the overriding method can throw nothing here's again what the overriding method can throw:

1) throw the same exception

public static class A 
{
    public void m1()
       throws IOException
    {
        System.out.println("A m1");
    }

}

public static class B 
    extends A
{
    @Override
    public void m1()
        throws IOException
    {
        System.out.println("B m1");
    }
}

2) throw subclass of the overriden method's thrown exception

public static class A 
{
    public void m2()
       throws Exception
    {
        System.out.println("A m2");
    }

}

public static class B 
    extends A
{
    @Override
    public void m2()
        throws IOException
    {
        System.out.println("B m2");
    }
}

3) throw nothing.

public static class A 
{   
    public void m3()
       throws IOException
    {
        System.out.println("A m3");
    }
}

public static class B 
    extends A
{   
    @Override
    public void m3()
        //throws NOTHING
    {
        System.out.println("B m3");
    }
}

4) Having RuntimeExceptions in throws is not required.

There can be RuntimeExceptions in throws or not, compiler won't complain about it. RuntimeExceptions are not checked exceptions. Only checked exceptions are required to appear in throws if not catched.

asp.net: Invalid postback or callback argument

This error can also be caused by nested <form> tag in the master page which is not allowed.

<form id="someid"></form>

This will likely be the cause if you have picked up a template and copying the code from somewhere as it.

Solution

You have to break the nesting of <form> tag. The following should become

<form method="" name="form1">
  <form method="" name="form2>
  </form>
</form>

should become

<form method="" name="form1">    
</form>

<form method="" name="form2>    
</form>

Strings and character with printf

If you try this:

#include<stdio.h>

void main()
{
 char name[]="siva";
 printf("name = %p\n", name);
 printf("&name[0] = %p\n", &name[0]);
 printf("name printed as %%s is %s\n",name);
 printf("*name = %c\n",*name);
 printf("name[0] = %c\n", name[0]);
}

Output is:

name = 0xbff5391b  
&name[0] = 0xbff5391b
name printed as %s is siva
*name = s
name[0] = s

So 'name' is actually a pointer to the array of characters in memory. If you try reading the first four bytes at 0xbff5391b, you will see 's', 'i', 'v' and 'a'

Location     Data
=========   ======

0xbff5391b    0x73  's'  ---> name[0]
0xbff5391c    0x69  'i'  ---> name[1]
0xbff5391d    0x76  'v'  ---> name[2]
0xbff5391e    0x61  'a'  ---> name[3]
0xbff5391f    0x00  '\0' ---> This is the NULL termination of the string

To print a character you need to pass the value of the character to printf. The value can be referenced as name[0] or *name (since for an array name = &name[0]).

To print a string you need to pass a pointer to the string to printf (in this case 'name' or '&name[0]').

In Node.js, how do I turn a string to a json?

use the JSON function >

JSON.parse(theString)

SQL: capitalize first letter only

Please check the query without using a function:

declare @T table(Insurance varchar(max))

insert into @T values ('wezembeek-oppem')
insert into @T values ('roeselare')
insert into @T values ('BRUGGE')
insert into @T values ('louvain-la-neuve')

select (
       select upper(T.N.value('.', 'char(1)'))+
                lower(stuff(T.N.value('.', 'varchar(max)'), 1, 1, ''))+(CASE WHEN RIGHT(T.N.value('.', 'varchar(max)'), 1)='-' THEN '' ELSE ' ' END)
       from X.InsXML.nodes('/N') as T(N)
       for xml path(''), type
       ).value('.', 'varchar(max)') as Insurance
from 
  (
  select cast('<N>'+replace(
            replace(
                Insurance, 
                ' ', '</N><N>'),
            '-', '-</N><N>')+'</N>' as xml) as InsXML
  from @T
  ) as X

Convert a List<T> into an ObservableCollection<T>

The Observable Collection constructor will take an IList or an IEnumerable.

If you find that you are going to do this a lot you can make a simple extension method:

    public static ObservableCollection<T> ToObservableCollection<T>(this IEnumerable<T> enumerable)
    {
        return new ObservableCollection<T>(enumerable);
    }

Use Awk to extract substring

You don't need awk for this...

echo aaa0.bbb.ccc | cut -d. -f1
cut -d. -f1 <<< aaa0.bbb.ccc

echo aaa0.bbb.ccc | { IFS=. read a _ ; echo $a ; }
{ IFS=. read a _ ; echo $a ; } <<< aaa0.bbb.ccc 

x=aaa0.bbb.ccc; echo ${x/.*/}

Heavier options:

sed:
echo aaa0.bbb.ccc | sed 's/\..*//'
sed 's/\..*//' <<< aaa0.bbb.ccc 
awk:
echo aaa0.bbb.ccc | awk -F. '{print $1}'
awk -F. '{print $1}' <<< aaa0.bbb.ccc 

Installing TensorFlow on Windows (Python 3.6.x)

Windows batch file for installing TensorFlow and Python 3.5 on Windows. The issue is that as of this date, TensorFlow is not updated to support Python 3.6+ and will not install. Additionally, many systems have an incompatible version of Python. This batch file should create a compatible environment without effecting other Python installs. See REM comments for assumptions.

REM download Anaconda3-4.2.0-Windows-x86_64.exe (contains python 3.5) from https://repo.continuum.io/archive/index.html
REM Assumes download is in %USERPROFILE%\Downloads
%USERPROFILE%\Downloads\Anaconda3-4.2.0-Windows-x86_64.exe

REM change path to use Anaconda3 (python 3.5).
PATH %USERPROFILE%\Anaconda3;%USERPROFILE%\Anaconda3\Scripts;%USERPROFILE%\Anaconda3\Library\bin;%PATH%

REM update pip to 9.0 or later (mandatory)
python -m pip install --upgrade pip

REM tell conda where to load tensorflow
conda config --add channels conda-forge

REM elevate command (mandatory) and install tensorflow - use explicit path to conda %USERPROFILE%\Anaconda3\scripts\conda
powershell.exe -Command start-process -verb runas cmd {/K "%USERPROFILE%\Anaconda3\scripts\conda install tensorflow"}

Be sure the above PATH is used when invoking TensorFlow.

Handling very large numbers in Python

The python interpreter will handle it for you, you just have to do your operations (+, -, *, /), and it will work as normal.

The int value is unlimited.

Careful when doing division, by default the quotient is turned into float, but float does not support such large numbers. If you get an error message saying float does not support such large numbers, then it means the quotient is too large to be stored in float you’ll have to use floor division (//).

It ignores any decimal that comes after the decimal point, this way, the result will be int, so you can have a large number result.

>>>10//3
3

>>>10//4
2

How to export query result to csv in Oracle SQL Developer?

Not exactly "exporting," but you can select the rows (or Ctrl-A to select all of them) in the grid you'd like to export, and then copy with Ctrl-C.

The default is tab-delimited. You can paste that into Excel or some other editor and manipulate the delimiters all you like.

Also, if you use Ctrl-Shift-C instead of Ctrl-C, you'll also copy the column headers.

Pandas dataframe groupby plot

Simple plot,

you can use:

df.plot(x='Date',y='adj_close')

Or you can set the index to be Date beforehand, then it's easy to plot the column you want:

df.set_index('Date', inplace=True)
df['adj_close'].plot()

If you want a chart with one series by ticker on it

You need to groupby before:

df.set_index('Date', inplace=True)
df.groupby('ticker')['adj_close'].plot(legend=True)

enter image description here


If you want a chart with individual subplots:

grouped = df.groupby('ticker')

ncols=2
nrows = int(np.ceil(grouped.ngroups/ncols))

fig, axes = plt.subplots(nrows=nrows, ncols=ncols, figsize=(12,4), sharey=True)

for (key, ax) in zip(grouped.groups.keys(), axes.flatten()):
    grouped.get_group(key).plot(ax=ax)

ax.legend()
plt.show()

enter image description here

Searching a list of objects in Python

Simple, Elegant, and Powerful:

A generator expression in conjuction with a builtin… (python 2.5+)

any(x for x in mylist if x.n == 10)

Uses the Python any() builtin, which is defined as follows:

any(iterable) -> Return True if any element of the iterable is true. Equivalent to:

def any(iterable):
    for element in iterable:
        if element:
            return True
    return False

Downcasting in Java

I believe this applies to all statically typed languages:

String s = "some string";
Object o = s; // ok
String x = o; // gives compile-time error, o is not neccessarily a string
String x = (String)o; // ok compile-time, but might give a runtime exception if o is not infact a String

The typecast effectively says: assume this is a reference to the cast class and use it as such. Now, lets say o is really an Integer, assuming this is a String makes no sense and will give unexpected results, thus there needs to be a runtime check and an exception to notify the runtime environment that something is wrong.

In practical use, you can write code working on a more general class, but cast it to a subclass if you know what subclass it is and need to treat it as such. A typical example is overriding Object.equals(). Assume we have a class for Car:

@Override
boolean equals(Object o) {
    if(!(o instanceof Car)) return false;
    Car other = (Car)o;
    // compare this to other and return
}

Is 'bool' a basic datatype in C++?

Yes, C++ supports bool and it is a data type. For reference - Bool data type

AngularJS: How do I manually set input to $valid in controller?

I came across this post w/a similar issue. My fix was to add a hidden field to hold my invalid state for me.

<input type="hidden" ng-model="vm.application.isValid" required="" />

In my case I had a nullable bool which a person had to select one of two different buttons. if they answer yes, an entity is added to the collection and the state of the button changes. Until all of the questions get answered, (one of the buttons in each of the pairs has a click) the form is not valid.

vm.hasHighSchool = function (attended) { 
  vm.application.hasHighSchool = attended;
  applicationSvc.addSchool(attended, 1, vm.application);
}
<input type="hidden" ng-model="vm.application.hasHighSchool" required="" />
<div class="row">
  <div class="col-lg-3"><label>Did You Attend High School?</label><label class="required" ng-hide="vm.application.hasHighSchool != undefined">*</label></div>
  <div class="col-lg-2">
    <button value="Yes" title="Yes" ng-click="vm.hasHighSchool(true)" class="btn btn-default" ng-class="{'btn-success': vm.application.hasHighSchool == true}">Yes</button>
    <button value="No" title="No" ng-click="vm.hasHighSchool(false)" class="btn btn-default" ng-class="{'btn-success':  vm.application.hasHighSchool == false}">No</button>
  </div>
</div>

How to input a path with a white space?

If the file contains only parameter assignments, you can use the following loop in place of sourcing it:

# Instead of source file.txt
while IFS="=" read name value; do
    declare "$name=$value"
done < file.txt

This saves you having to quote anything in the file, and is also more secure, as you don't risk executing arbitrary code from file.txt.

IE9 jQuery AJAX with CORS returns "Access is denied"

Update as of early 2015. xDomain is a widely used library to supports CORS on IE9 with limited extra coding.

https://github.com/jpillora/xdomain

Vertically and horizontally centering text in circle in CSS (like iphone notification badge)

Interesting question! While there are plenty of guides on horizontally and vertically centering a div, an authoritative treatment of the subject where the centered div is of an unpredetermined width is conspicuously absent.

Let's apply some basic constraints:

  • No Javascript
  • No mangling of the display property to table-cell, which is of questionable support status

Given this, my entry into the fray is the use of the inline-block display property to horizontally center the span within an absolutely positioned div of predetermined height, vertically centered within the parent container in the traditional top: 50%; margin-top: -123px fashion.

Markup: div > div > span

CSS:

body > div { position: relative; height: XYZ; width: XYZ; }
div > div { 
  position: absolute;
  top: 50%;
  height: 30px;
  margin-top: -15px; 
  text-align: center;}
div > span { display: inline-block; }

Source: http://jsfiddle.net/38EFb/


An alternate solution that doesn't require extraneous markups but that very likely produces more problems than it solves is to use the line-height property. Don't do this. But it is included here as an academic note: http://jsfiddle.net/gucwW/

Find out the history of SQL queries

You can use this sql statement to get the history for any date:

SELECT * FROM V$SQL V where  to_date(v.FIRST_LOAD_TIME,'YYYY-MM-DD hh24:mi:ss') > sysdate - 60

How to create a GUID / UUID

I adjusted my own UUID/GUID generator with some extras here.

I'm using the following Kybos random number generator to be a bit more cryptographically sound.

Below is my script with the Mash and Kybos methods from baagoe.com excluded.

//UUID/Guid Generator
// use: UUID.create() or UUID.createSequential()
// convenience:  UUID.empty, UUID.tryParse(string)
(function(w){
  // From http://baagoe.com/en/RandomMusings/javascript/
  // Johannes Baagøe <[email protected]>, 2010
  //function Mash() {...};

  // From http://baagoe.com/en/RandomMusings/javascript/
  //function Kybos() {...};

  var rnd = Kybos();

  //UUID/GUID Implementation from http://frugalcoder.us/post/2012/01/13/javascript-guid-uuid-generator.aspx
  var UUID = {
    "empty": "00000000-0000-0000-0000-000000000000"
    ,"parse": function(input) {
      var ret = input.toString().trim().toLowerCase().replace(/^[\s\r\n]+|[\{\}]|[\s\r\n]+$/g, "");
      if ((/[a-f0-9]{8}\-[a-f0-9]{4}\-[a-f0-9]{4}\-[a-f0-9]{4}\-[a-f0-9]{12}/).test(ret))
        return ret;
      else
        throw new Error("Unable to parse UUID");
    }
    ,"createSequential": function() {
      var ret = new Date().valueOf().toString(16).replace("-","")
      for (;ret.length < 12; ret = "0" + ret);
      ret = ret.substr(ret.length-12,12); //only least significant part
      for (;ret.length < 32;ret += Math.floor(rnd() * 0xffffffff).toString(16));
      return [ret.substr(0,8), ret.substr(8,4), "4" + ret.substr(12,3), "89AB"[Math.floor(Math.random()*4)] + ret.substr(16,3),  ret.substr(20,12)].join("-");
    }
    ,"create": function() {
      var ret = "";
      for (;ret.length < 32;ret += Math.floor(rnd() * 0xffffffff).toString(16));
      return [ret.substr(0,8), ret.substr(8,4), "4" + ret.substr(12,3), "89AB"[Math.floor(Math.random()*4)] + ret.substr(16,3),  ret.substr(20,12)].join("-");
    }
    ,"random": function() {
      return rnd();
    }
    ,"tryParse": function(input) {
      try {
        return UUID.parse(input);
      } catch(ex) {
        return UUID.empty;
      }
    }
  };
  UUID["new"] = UUID.create;

  w.UUID = w.Guid = UUID;
}(window || this));

List all environment variables from the command line

Just do:

SET

You can also do SET prefix to see all variables with names starting with prefix.

For example, if you want to read only derbydb from the environment variables, do the following:

set derby 

...and you will get the following:

DERBY_HOME=c:\Users\amro-a\Desktop\db-derby-10.10.1.1-bin\db-derby-10.10.1.1-bin

How to force a WPF binding to refresh?

MultiBinding friendly version...

private void ComboBox_Loaded(object sender, RoutedEventArgs e)
{
    BindingOperations.GetBindingExpressionBase((ComboBox)sender, ComboBox.ItemsSourceProperty).UpdateTarget();
}

Detect iPhone/iPad purely by css

iPhone & iPod touch:

<link rel="stylesheet" media="only screen and (max-device-width: 480px)" href="../iphone.css" type="text/css" />

iPhone 4 & iPod touch 4G:

<link rel="stylesheet" media="only screen and (-webkit-min-device-pixel-ratio: 2)" type="text/css" href="../iphone4.css" />

iPad:

<link rel="stylesheet" media="only screen and (max-device-width: 1024px)" href="../ipad.css" type="text/css" />

Get only records created today in laravel

I’ve seen people doing it with raw queries, like this:

$q->where(DB::raw("DATE(created_at) = '".date('Y-m-d')."'"));

Or without raw queries by datetime, like this:

$q->where('created_at', '>=', date('Y-m-d').' 00:00:00'));

Luckily, Laravel Query Builder offers a more Eloquent solution:

$q->whereDate('created_at', '=', date('Y-m-d'));

Or, of course, instead of PHP date() you can use Carbon:

$q->whereDate('created_at', '=', Carbon::today()->toDateString());

It’s not only whereDate. There are three more useful functions to filter out dates:

$q->whereDay('created_at', '=', date('d'));
$q->whereMonth('created_at', '=', date('m'));
$q->whereYear('created_at', '=', date('Y'));

Show hide fragment in android

Hi you do it by using this approach, all fragments will remain in the container once added initially and then we are simply revealing the desired fragment and hiding the others within the container.

// Within an activity
private FragmentA fragmentA;
private FragmentB fragmentB;
private FragmentC fragmentC;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if (savedInstanceState == null) {
        fragmentA = FragmentA.newInstance("foo");
        fragmentB = FragmentB.newInstance("bar");
        fragmentC = FragmentC.newInstance("baz");
    }
}


// Replace the switch method
protected void displayFragmentA() {
    FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
    if (fragmentA.isAdded()) { // if the fragment is already in container
        ft.show(fragmentA);
    } else { // fragment needs to be added to frame container
        ft.add(R.id.flContainer, fragmentA, "A");
    }
    // Hide fragment B
    if (fragmentB.isAdded()) { ft.hide(fragmentB); }
    // Hide fragment C
    if (fragmentC.isAdded()) { ft.hide(fragmentC); }
    // Commit changes
    ft.commit();
}

Please see https://github.com/codepath/android_guides/wiki/Creating-and-Using-Fragments for more info. I hope I get to help anyone. Even if it this is an old question.

When to use static classes in C#

For C# 3.0, extension methods may only exist in top-level static classes.

moving changed files to another branch for check-in

A soft git reset will put committed changes back into your index. Next, checkout the branch you had intended to commit on. Then git commit with a new commit message.

  1. git reset --soft <commit>

  2. git checkout <branch>

  3. git commit -m "Commit message goes here"

From git docs:

git reset [<mode>] [<commit>] This form resets the current branch head to and possibly updates the index (resetting it to the tree of ) and the working tree depending on . If is omitted, defaults to --mixed. The must be one of the following:

--soft Does not touch the index file or the working tree at all (but resets the head to , just like all modes do). This leaves all your changed files "Changes to be committed", as git status would put it.

How to concatenate and minify multiple CSS and JavaScript files with Grunt.js (0.3.x)

I want to mention here a very, VERY, interesting technique that is being used in huge projects like jQuery and Modernizr for concatenate things.

Both of this projects are entirely developed with requirejs modules (you can see that in their github repos) and then they use the requirejs optimizer as a very smart concatenator. The interesting thing is that, as you can see, nor jQuery neither Modernizr needs on requirejs to work, and this happen because they erase the requirejs syntatic ritual in order to get rid of requirejs in their code. So they end up with a standalone library that was developed with requirejs modules! Thanks to this they are able to perform cutsom builds of their libraries, among other advantages.

For all those interested in concatenation with the requirejs optimizer, check out this post

Also there is a small tool that abstracts all the boilerplate of the process: AlbanilJS

Download an SVN repository?

Install svn, navigate to your directory then run the command svn checkout <url-to-repostitory> ..

Please provide us with some details like your operating system and what/where you want to download.

I'm getting the "missing a using directive or assembly reference" and no clue what's going wrong

.Net framework of the referencing dll should be same as the .Net framework version of the Project in which dll is referred

Skip first line(field) in loop using CSV file?

csvreader.next() Return the next row of the reader’s iterable object as a list, parsed according to the current dialect.

Make Font Awesome icons in a circle?

UPDATE:

Upon learning flex recently, there is a cleaner way (no tables and less css). Set the wrapper as display: flex; and to center it's children give it the properties align-items: center; for (vertical) and justify-content: center; (horizontal) centering.

See this updated JS Fiddle


Strange that nobody suggested this before.. I always use tables to do this.
Simply make a wrapper have display: table and center stuff inside it with text-align: center for horizontal and vertical-align: middle for vertical alignment.

<div class='wrapper'>
  <i class='icon fa fa-bars'></i>
</div>

and some sass like this

.wrapper{
  display: table; 

  i{
    display: table-cell;
    vertical-align: middle;
    text-align: center;
  }

}

or see this JS Fiddle

Change image in HTML page every few seconds

As of current edited version of the post, you call setInterval at each change's end, adding a new "changer" with each new iterration. That means after first run, there's one of them ticking in memory, after 100 runs, 100 different changers change image 100 times every second, completely destroying performance and producing confusing results.

You only need to "prime" setInterval once. Remove it from function and place it inside onload instead of direct function call.

Sort JavaScript object by key

Use this code if you have nested objects or if you have nested array obj.

var sortObjectByKey = function(obj){
    var keys = [];
    var sorted_obj = {};
    for(var key in obj){
        if(obj.hasOwnProperty(key)){
            keys.push(key);
        }
    }
    // sort keys
    keys.sort();

    // create new array based on Sorted Keys
    jQuery.each(keys, function(i, key){
        var val = obj[key];
        if(val instanceof Array){
            //do for loop;
            var arr = [];
            jQuery.each(val,function(){
                arr.push(sortObjectByKey(this));
            }); 
            val = arr;

        }else if(val instanceof Object){
            val = sortObjectByKey(val)
        }
        sorted_obj[key] = val;
    });
    return sorted_obj;
};

Display all dataframe columns in a Jupyter Python Notebook

you can use pandas.set_option(), for column, you can specify any of these options

pd.set_option("display.max_rows", 200)
pd.set_option("display.max_columns", 100)
pd.set_option("display.max_colwidth", 200)

For full print column, you can use like this

import pandas as pd
pd.set_option('display.max_colwidth', -1)
print(words.head())

enter image description here

Find length (size) of an array in jquery

testvar[1] is the value of that array index, which is the number 2. Numbers don't have a length property, and you're checking for 2.length which is undefined. If you want the length of the array just check testvar.length

How to exclude property from Json Serialization

Sorry I decided to write another answer since none of the other answers are copy-pasteable enough.

If you don't want to decorate properties with some attributes, or if you have no access to the class, or if you want to decide what to serialize during runtime, etc. etc. here's how you do it in Newtonsoft.Json

//short helper class to ignore some properties from serialization
public class IgnorePropertiesResolver : DefaultContractResolver
{
    private readonly HashSet<string> ignoreProps;
    public IgnorePropertiesResolver(IEnumerable<string> propNamesToIgnore)
    {
        this.ignoreProps = new HashSet<string>(propNamesToIgnore);
    }

    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
    {
        JsonProperty property = base.CreateProperty(member, memberSerialization);
        if (this.ignoreProps.Contains(property.PropertyName))
        {
            property.ShouldSerialize = _ => false;
        }
        return property;
    }
}

Usage

JsonConvert.SerializeObject(YourObject, new JsonSerializerSettings()
        { ContractResolver = new IgnorePropertiesResolver(new[] { "Prop1", "Prop2" }) };);

Note: make sure you cache the ContractResolver object if you decide to use this answer, otherwise performance may suffer.

I've published the code here in case anyone wants to add anything

https://github.com/jitbit/JsonIgnoreProps

Changing CSS for last <li>

One alternative for IE7+ and other browsers may be to use :first-child instead, and invert your styles.

For example, if you're setting the margin on each li:

ul li {
  margin-bottom: 1em;
}
ul li:last-child {
  margin-bottom: 0;
}

You could replace it with this:

ul li {
  margin-top: 1em;
}
ul li:first-child {
  margin-top: 0;
}

This will work well for some other cases like borders.

According to sitepoint, :first-child buggy, but only to the extent that it will select some root elements (the doctype or html), and may not change styles if other elements are inserted.

How to set value in @Html.TextBoxFor in Razor syntax?

The problem is that you are using a lower case v.

You need to set it to Value and it should fix your issue:

@Html.TextBoxFor(model => model.Destination, new { id = "txtPlace", Value= "3" })

SQL Server Case Statement when IS NULL

Your hyphen in your ELSE statement isn't accepted in the column which is being defined under the datetime data type. You could either:

a) Wrap a CAST around your [stat] field to convert it to a varchar representation of a date

b) Use a datetime like 9999-12-31 for your ELSE value.

Get child node index

Could you do something like this:

var index = Array.prototype.slice.call(element.parentElement.children).indexOf(element);

https://developer.mozilla.org/en-US/docs/Web/API/Node/parentElement

Python3: ImportError: No module named '_ctypes' when using Value from module multiprocessing

Detailed steps to install Python 3.7 in CentOS or any redhat linux machine:

  1. Download Python from https://www.python.org/ftp/python/3.7.0/Python-3.7.0.tar.xz
  2. Extract the content in new folder
  3. Open Terminal in the same directory
  4. Run below code step by step :
sudo yum -y install gcc gcc-c++ 
sudo yum -y install zlib zlib-devel
sudo yum -y install libffi-devel 
./configure
make
make install

A Java collection of value pairs? (tuples?)

This is based on JavaHelp4u 's code.

Less verbose and shows how to do in one line and how to loop over things.

//======>  Imports
import java.util.AbstractMap.SimpleEntry;
import java.util.ArrayList;
import java.util.List;
import java.util.Map.Entry;

//======>  Single Entry
SimpleEntry<String, String> myEntry = new SimpleEntry<String, String>("ID", "Text");
System.out.println("key: " + myEntry.getKey() + "    value:" + myEntry.getValue());
System.out.println();

//======>  List of Entries
List<Entry<String,String>> pairList = new ArrayList<>();

//-- Specify manually
Entry<String,String> firstButton = new SimpleEntry<String, String>("Red ", "Way out");
pairList.add(firstButton);

//-- one liner:
pairList.add(new SimpleEntry<String,String>("Gray", "Alternate route"));  //Ananomous add.

//-- Iterate over Entry array:
for (Entry<String, String> entr : pairList) {
    System.out.println("Button: " + entr.getKey() + "    Label: " + entr.getValue());
}

How to Execute a Python File in Notepad ++?

I also wanted to run python files directly from Notepad++. Most common option found online is using builtin option Run. Then you have two options:

  1. Run python file in console (in Windows it is Command Prompt) with code something like this (links: enter image description here enter image description here enter image description here):

    C:\Path\to\Python\python.exe "$(FULL_CURRENT_PATH)"
    

    (If your console window immediately closes after running then you can add cmd /k to your code. Links: enter image description here enter image description here enter image description here enter image description here) This works fine, and you can even run files in interactive mode by adding -i to your code (links: enter image description here enter image description here enter image description here enter image description here enter image description here enter image description here enter image description here enter image description here).

  2. Run python program in IDLE with code something like this (links: enter image description here enter image description here enter image description here enter image description here, in these links C:\Path\to\Python\Lib\idlelib\idle.py is used, but I am using C:\Path\to\Python\Lib\idlelib\idle.bat instead, because idle.bat sets the right current working directory automatically):

    C:\Path\to\Python\Lib\idlelib\idle.bat "$(FULL_CURRENT_PATH)"
    

    Actually, this doesn't run your program in IDLE Shell, but instead it opens your python file in IDLE Editor and then you need to click Run Module (or click F5) to run the program. So it opens your file in IDLE Editor and then you need run it from there, which defeats the purpose of running python files from Notepad++.

    But, searching online, I found option which adds '-r' to your code (links: enter image description here enter image description here enter image description here enter image description here enter image description here):

    C:\Path\to\Python\Lib\idlelib\idle.bat -r "$(FULL_CURRENT_PATH)"
    

    This will run your python program in IDLE Shell and because it is in IDLE it is by default in interactive mode.

Problem with running your python files via builtin Run option is that each time you run your python file, you open new console or IDLE window and lose all output from previous executions. This might not be important to some, but when I started to program in python, I used Python IDLE, so I got used to running python file multiple times in same IDLE Shell window. Also problem with running python programs from Notepad++ is that you need to manually save your file and then click Run (or press F5). To solve these problems (AFAIK*) you need to use Notepad++ Plugins. The best plugin for running python files from Notepad++ is NppExec. (I also tried PyNPP and Python Script. PyNPP runs python files in console, it works, but you can do that without plugin via builtin Run option and Python Script is used for running scripts that interact with Notepad++ so you can't run your python files.) To run your python file with NppExec plugin you need to go to Plugins -> NppExec -> Execute and then type in something like this (links: enter image description here enter image description here):

C:\Path\to\Python\python.exe "$(FULL_CURRENT_PATH)"

With NppExec you can also save your python file before run with npp_save command, set working directory with cd "$(CURRENT_DIRECTORY)" command or run python program in interactive mode with -i command. I found many links (enter image description here enter image description here enter image description here enter image description here enter image description here) online that mention these options, but best use of NppExec to run python programs I found at NppExec's Manual which has chapter 4.6.4. Running Python & wxPython with this code:

npp_console -  // disable any output to the Console
npp_save  // save current file (a .py file is expected)
cd "$(CURRENT_DIRECTORY)"  // use the current file's dir
set local @exit_cmd_silent = exit()  // allows to exit Python automatically
set local PATH_0 = $(SYS.PATH)  // current value of %PATH%
env_set PATH = $(SYS.PATH);C:\Python27  // use Python 2.7
npp_setfocus con  // set the focus to the Console
npp_console +  // enable output to the Console
python -i -u "$(FILE_NAME)"  // run Python's program interactively
npp_console -  // disable any output to the Console
env_set PATH = $(PATH_0)  // restore the value of %PATH%
npp_console +  // enable output to the Console

All you need to do is copy this code and change your python directory if you use some other python version (e.g.* I am using python 3.4 so my directory is C:\Python34). This code works perfectly, but there is one line I added to this code so I can run python program multiple times without loosing previous output:

npe_console m- a+

a+ is to enable the "append" mode which keeps the previous Console's text and does not clear it.

m- turns off console's internal messages (those are in green color)

The final code that I use in NppExec's Execute window is:

npp_console -  // disable any output to the Console
npp_save  // save current file (a .py file is expected)
cd "$(CURRENT_DIRECTORY)"  // use the current file's dir
set local @exit_cmd_silent = exit()  // allows to exit Python automatically
set local PATH_0 = $(SYS.PATH)  // current value of %PATH%
env_set PATH = $(SYS.PATH);C:\Python34  // use Python 3.4
npp_setfocus con  // set the focus to the Console
npe_console m- a+
npp_console +  // enable output to the Console
python -i -u "$(FILE_NAME)"  // run Python's program interactively
npp_console -  // disable any output to the Console
env_set PATH = $(PATH_0)  // restore the value of %PATH%
npp_console +  // enable output to the Console

You can save your NppExec's code, and assign a shortcut key to this NppExec's script. (You need to open Advanced options of NppExec's plugin, select your script in the Associated script drop-down list, press the Add/Modify, restart Notepad++ , go to Notepad++'es Settings -> Shortcut Mapper -> Plugin commands, select your script, click Modify and assign a shortcut key. I wanted to put F5 as my shortcut key, to do that you need to change shortcut key for builtin option Run to something else first.) Links to chapters from NppExec's Manual that explain how to save you NppExec's code and assign a shortcut key: NppExec's "Execute...", NppExec's script.

P.S.*: With NppExec plugin you can add Highlight Filters (found in Console Output Filters...) that highlight certain lines. I use it to highlight error lines in red, to do that you need to add Highlight masks: *File "%FILE%", line %LINE%, in <*> and Traceback (most recent call last): like this.

How to fast get Hardware-ID in C#?

For more details refer to this link

The following code will give you CPU ID:

namespace required System.Management

var mbs = new ManagementObjectSearcher("Select ProcessorId From Win32_processor");
ManagementObjectCollection mbsList = mbs.Get();
string id = "";
foreach (ManagementObject mo in mbsList)
{
    id = mo["ProcessorId"].ToString();
    break;
}

For Hard disk ID and motherboard id details refer this-link

To speed up this procedure, make sure you don't use SELECT *, but only select what you really need. Use SELECT * only during development when you try to find out what you need to use, because then the query will take much longer to complete.

How to do a HTTP HEAD request from the windows command line?

I'd download PuTTY and run a telnet session on port 80 to the webserver you want

HEAD /resource HTTP/1.1
Host: www.example.com

You could alternatively download Perl and try LWP's HEAD command. Or write your own script.

Error - Android resource linking failed (AAPT2 27.0.3 Daemon #0)

Note: Android Studio spits out a load of crazy errors like this if you upgrade the support libraries to 28.0.0 and your compileSdkVersion is not 28 also.

Make scrollbars only visible when a Div is hovered over?

This will help you to overcome overflow: overlay issues as well.

.div{
      height: 300px;
      overflow: auto;
      visibility: hidden;
    }

.div-content,
.div:hover {
  visibility: visible;
}

How to convert this var string to URL in Swift

In Swift3:
let fileUrl = Foundation.URL(string: filePath)