Programs & Examples On #Chord

How to open a link in new tab (chrome) using Selenium WebDriver?

I checked with below code and it works fine for me. I found answer from here.

    driver = new ChromeDriver();
    driver.manage().window().maximize();
            
    String baseUrl = "http://www.google.co.uk/";
    driver.get(baseUrl);
    driver.findElement(By.cssSelector("body")).sendKeys(Keys.CONTROL +"t");

    ArrayList<String> tabs = new ArrayList<String> (driver.getWindowHandles());
    driver.switchTo().window(tabs.get(1)); //switches to new tab
    driver.get("https://www.facebook.com");
    
    driver.switchTo().window(tabs.get(0)); // switch back to main screen        
    driver.get("https://www.news.google.com");

Find row number of matching value

For your first method change ws.Range("A") to ws.Range("A:A") which will search the entirety of column a, like so:

Sub Find_Bingo()

        Dim wb As Workbook
        Dim ws As Worksheet
        Dim FoundCell As Range
        Set wb = ActiveWorkbook
        Set ws = ActiveSheet

            Const WHAT_TO_FIND As String = "Bingo"

            Set FoundCell = ws.Range("A:A").Find(What:=WHAT_TO_FIND)
            If Not FoundCell Is Nothing Then
                MsgBox (WHAT_TO_FIND & " found in row: " & FoundCell.Row)
            Else
                MsgBox (WHAT_TO_FIND & " not found")
            End If
End Sub

For your second method, you are using Bingo as a variable instead of a string literal. This is a good example of why I add Option Explicit to the top of all of my code modules, as when you try to run the code it will direct you to this "variable" which is undefined and not intended to be a variable at all.

Additionally, when you are using With...End With you need a period . before you reference Cells, so Cells should be .Cells. This mimics the normal qualifying behavior (i.e. Sheet1.Cells.Find..)

Change Bingo to "Bingo" and change Cells to .Cells

With Sheet1
        Set FoundCell = .Cells.Find(What:="Bingo", After:=.Cells(1, 1), _
        LookIn:=xlValues, lookat:=xlPart, SearchOrder:=xlByRows, _
        SearchDirection:=xlNext, MatchCase:=False, SearchFormat:=False)
    End With

If Not FoundCell Is Nothing Then
        MsgBox ("""Bingo"" found in row " & FoundCell.Row)
Else
        MsgBox ("Bingo not found")
End If

Update

In my

With Sheet1
    .....
End With

The Sheet1 refers to a worksheet's code name, not the name of the worksheet itself. For example, say I open a new blank Excel workbook. The default worksheet is just Sheet1. I can refer to that in code either with the code name of Sheet1 or I can refer to it with the index of Sheets("Sheet1"). The advantage to using a codename is that it does not change if you change the name of the worksheet.

Continuing this example, let's say I renamed Sheet1 to Data. Using Sheet1 would continue to work, as the code name doesn't change, but now using Sheets("Sheet1") would return an error and that syntax must be updated to the new name of the sheet, so it would need to be Sheets("Data").

In the VB Editor you would see something like this:

code object explorer example

Notice how, even though I changed the name to Data, there is still a Sheet1 to the left. That is what I mean by codename.

The Data worksheet can be referenced in two ways:

Debug.Print Sheet1.Name
Debug.Print Sheets("Data").Name

Both should return Data

More discussion on worksheet code names can be found here.

How to make `setInterval` behave more in sync, or how to use `setTimeout` instead?

Use let instead of var in code :

for(let i=1;i<=5;i++){setTimeout(()=>{console.log(i)},1000);}

Ways to iterate over a list in Java

A JDK8-style iteration:

public class IterationDemo {

    public static void main(String[] args) {
        List<Integer> list = Arrays.asList(1, 2, 3);
        list.stream().forEach(elem -> System.out.println("element " + elem));
    }
}

AngularJS: factory $http.get JSON file

I have approximately these problem. I need debug AngularJs application from Visual Studio 2013.

By default IIS Express restricted access to local files (like json).

But, first: JSON have JavaScript syntax.

Second: javascript files is allowed.

So:

  1. rename JSON to JS (data.json->data.js).

  2. correct load command ($http.get('App/data.js').success(function (data) {...

  3. load script data.js to page (<script src="App/data.js"></script>)

Next use loaded data an usual manner. It is just workaround, of course.

How to find text in a column and saving the row number where it is first found - Excel VBA

I'm not really familiar with all those parameters of the Find method; but upon shortening it, the following is working for me:

With WB.Sheets("ECM Overview")
    Set FindRow = .Range("A:A").Find(What:="ProjTemp", LookIn:=xlValues)
End With

And if you solely need the row number, you can use this after:

Dim FindRowNumber As Long
.....
FindRowNumber = FindRow.Row

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

I'd prefer to use the .Find method directly on a range object containing the range of cells to be searched. For original poster's code it might look like:

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

If cell Is Nothing Then
    'do something
Else
    'do something else
End If

I'd prefer to use more variables (and be sure to declare them) and let a lot of optional arguments use their default values:

Dim rng as Range
Dim cell as Range
Dim search as String

Set rng = ActiveSheet.Columns("B:B")
search = "String to Find"
Set cell = rng.Find(What:=search, LookIn:=xlFormulas, LookAt:=xlWhole, MatchCase:=False)

If cell Is Nothing Then
    'do something
Else
    'do something else
End If

I kept LookIn:=, LookAt::=, and MatchCase:= to be explicit about what is being matched. The other optional parameters control the order matches are returned in - I'd only specify those if the order is important to my application.

Returning a file to View/Download in ASP.NET MVC

Action method needs to return FileResult with either a stream, byte[], or virtual path of the file. You will also need to know the content-type of the file being downloaded. Here is a sample (quick/dirty) utility method. Sample video link How to download files using asp.net core

[Route("api/[controller]")]
public class DownloadController : Controller
{
    [HttpGet]
    public async Task<IActionResult> Download()
    {
        var path = @"C:\Vetrivel\winforms.png";
        var memory = new MemoryStream();
        using (var stream = new FileStream(path, FileMode.Open))
        {
            await stream.CopyToAsync(memory);
        }
        memory.Position = 0;
        var ext = Path.GetExtension(path).ToLowerInvariant();
        return File(memory, GetMimeTypes()[ext], Path.GetFileName(path));
    }

    private Dictionary<string, string> GetMimeTypes()
    {
        return new Dictionary<string, string>
        {
            {".txt", "text/plain"},
            {".pdf", "application/pdf"},
            {".doc", "application/vnd.ms-word"},
            {".docx", "application/vnd.ms-word"},
            {".png", "image/png"},
            {".jpg", "image/jpeg"},
            ...
        };
    }
}

HTML how to clear input using javascript?

<script type="text/javascript">
    function clearThis(target){
        if (target.value === "[email protected]") {
            target.value= "";
        }
    }
    </script>
<input type="text" name="email" value="[email protected]" size="30" onfocus="clearThis(this)">

Try it out here: http://jsfiddle.net/2K3Vp/

Get immediate first child element

Both these will give you the first child node:

console.log(parentElement.firstChild); // or
console.log(parentElement.childNodes[0]);

If you need the first child that is an element node then use:

console.log(parentElement.children[0]);

Edit

Ah, I see your problem now; parentElement is an array.

If you know that getElementsByClassName will only return one result, which it seems you do, you should use [0] to dearray (yes, I made that word up) the element:

var parentElement = document.getElementsByClassName("uniqueClassName")[0];

How to detect if multiple keys are pressed at once using JavaScript?

You should use the keydown event to keep track of the keys pressed, and you should use the keyup event to keep track of when the keys are released.

See this example: http://jsfiddle.net/vor0nwe/mkHsU/

(Update: I’m reproducing the code here, in case jsfiddle.net bails:) The HTML:

<ul id="log">
    <li>List of keys:</li>
</ul>

...and the Javascript (using jQuery):

var log = $('#log')[0],
    pressedKeys = [];

$(document.body).keydown(function (evt) {
    var li = pressedKeys[evt.keyCode];
    if (!li) {
        li = log.appendChild(document.createElement('li'));
        pressedKeys[evt.keyCode] = li;
    }
    $(li).text('Down: ' + evt.keyCode);
    $(li).removeClass('key-up');
});

$(document.body).keyup(function (evt) {
    var li = pressedKeys[evt.keyCode];
    if (!li) {
       li = log.appendChild(document.createElement('li'));
    }
    $(li).text('Up: ' + evt.keyCode);
    $(li).addClass('key-up');
});

In that example, I’m using an array to keep track of which keys are being pressed. In a real application, you might want to delete each element once their associated key has been released.

Note that while I've used jQuery to make things easy for myself in this example, the concept works just as well when working in 'raw' Javascript.

mysql - move rows from one table to another

I had to solve the same issue and this is what I used as solution.

To use this solution the source and destination table must be identical, and the must have an id unique and autoincrement in first table (so that the same id is never reused).

Lets say table1 and table2 have this structure

|id|field1|field2

You can make those two query :

INSERT INTO table2 SELECT * FROM table1 WHERE

DELETE FROM table1 WHERE table1.id in (SELECT table2.id FROM table2)

What is the origin of foo and bar?

tl;dr

  • "Foo" and "bar" as metasyntactic variables were popularised by MIT and DEC, the first references are in work on LISP and PDP-1 and Project MAC from 1964 onwards.

  • Many of these people were in MIT's Tech Model Railroad Club, where we find the first documented use of "foo" in tech circles in 1959 (and a variant in 1958).

  • Both "foo" and "bar" (and even "baz") were well known in popular culture, especially from Smokey Stover and Pogo comics, which will have been read by many TMRC members.

  • Also, it seems likely the military FUBAR contributed to their popularity.


The use of lone "foo" as a nonsense word is pretty well documented in popular culture in the early 20th century, as is the military FUBAR. (Some background reading: FOLDOC FOLDOC Jargon File Jargon File Wikipedia RFC3092)


OK, so let's find some references.

STOP PRESS! After posting this answer, I discovered this perfect article about "foo" in the Friday 14th January 1938 edition of The Tech ("MIT's oldest and largest newspaper & the first newspaper published on the web"), Volume LVII. No. 57, Price Three Cents:

On Foo-ism

The Lounger thinks that this business of Foo-ism has been carried too far by its misguided proponents, and does hereby and forthwith take his stand against its abuse. It may be that there's no foo like an old foo, and we're it, but anyway, a foo and his money are some party. (Voice from the bleachers- "Don't be foo-lish!")

As an expletive, of course, "foo!" has a definite and probably irreplaceable position in our language, although we fear that the excessive use to which it is currently subjected may well result in its falling into an early (and, alas, a dark) oblivion. We say alas because proper use of the word may result in such happy incidents as the following.

It was an 8.50 Thermodynamics lecture by Professor Slater in Room 6-120. The professor, having covered the front side of the blackboard, set the handle that operates the lift mechanism, turning meanwhile to the class to continue his discussion. The front board slowly, majestically, lifted itself, revealing the board behind it, and on that board, writ large, the symbols that spelled "FOO"!

The Tech newspaper, a year earlier, the Letter to the Editor, September 1937:

By the time the train has reached the station the neophytes are so filled with the stories of the glory of Phi Omicron Omicron, usually referred to as Foo, that they are easy prey.

...

It is not that I mind having lost my first four sons to the Grand and Universal Brotherhood of Phi Omicron Omicron, but I do wish that my fifth son, my baby, should at least be warned in advance.

Hopefully yours,

Indignant Mother of Five.

And The Tech in December 1938:

General trend of thought might be best interpreted from the remarks made at the end of the ballots. One vote said, '"I don't think what I do is any of Pulver's business," while another merely added a curt "Foo."


The first documented "foo" in tech circles is probably 1959's Dictionary of the TMRC Language:

FOO: the sacred syllable (FOO MANI PADME HUM); to be spoken only when under inspiration to commune with the Deity. Our first obligation is to keep the Foo Counters turning.

These are explained at FOLDOC. The dictionary's compiler Pete Samson said in 2005:

Use of this word at TMRC antedates my coming there. A foo counter could simply have randomly flashing lights, or could be a real counter with an obscure input.

And from 1996's Jargon File 4.0.0:

Earlier versions of this lexicon derived 'baz' as a Stanford corruption of bar. However, Pete Samson (compiler of the TMRC lexicon) reports it was already current when he joined TMRC in 1958. He says "It came from "Pogo". Albert the Alligator, when vexed or outraged, would shout 'Bazz Fazz!' or 'Rowrbazzle!' The club layout was said to model the (mythical) New England counties of Rowrfolk and Bassex (Rowrbazzle mingled with (Norfolk/Suffolk/Middlesex/Essex)."

A year before the TMRC dictionary, 1958's MIT Voo Doo Gazette ("Humor suplement of the MIT Deans' office") (PDF) mentions Foocom, in "The Laws of Murphy and Finagle" by John Banzhaf (an electrical engineering student):

Further research under a joint Foocom and Anarcom grant expanded the law to be all embracing and universally applicable: If anything can go wrong, it will!

Also 1964's MIT Voo Doo (PDF) references the TMRC usage:

Yes! I want to be an instant success and snow customers. Send me a degree in: ...

  • Foo Counters

  • Foo Jung


Let's find "foo", "bar" and "foobar" published in code examples.

So, Jargon File 4.4.7 says of "foobar":

Probably originally propagated through DECsystem manuals by Digital Equipment Corporation (DEC) in 1960s and early 1970s; confirmed sightings there go back to 1972.

The first published reference I can find is from February 1964, but written in June 1963, The Programming Language LISP: its Operation and Applications by Information International, Inc., with many authors, but including Timothy P. Hart and Michael Levin:

Thus, since "FOO" is a name for itself, "COMITRIN" will treat both "FOO" and "(FOO)" in exactly the same way.

Also includes other metasyntactic variables such as: FOO CROCK GLITCH / POOT TOOR / ON YOU / SNAP CRACKLE POP / X Y Z

I expect this is much the same as this next reference of "foo" from MIT's Project MAC in January 1964's AIM-064, or LISP Exercises by Timothy P. Hart and Michael Levin:

car[((FOO . CROCK) . GLITCH)]

It shares many other metasyntactic variables like: CHI / BOSTON NEW YORK / SPINACH BUTTER STEAK / FOO CROCK GLITCH / POOT TOOP / TOOT TOOT / ISTHISATRIVIALEXCERCISE / PLOOP FLOT TOP / SNAP CRACKLE POP / ONE TWO THREE / PLANE SUB THRESHER

For both "foo" and "bar" together, the earliest reference I could find is from MIT's Project MAC in June 1966's AIM-098, or PDP-6 LISP by none other than Peter Samson:

EXPLODE, like PRIN1, inserts slashes, so (EXPLODE (QUOTE FOO/ BAR)) PRIN1's as (F O O // / B A R) or PRINC's as (F O O / B A R).


Some more recallations.

@Walter Mitty recalled on this site in 2008:

I second the jargon file regarding Foo Bar. I can trace it back at least to 1963, and PDP-1 serial number 2, which was on the second floor of Building 26 at MIT. Foo and Foo Bar were used there, and after 1964 at the PDP-6 room at project MAC.

John V. Everett recalls in 1996:

When I joined DEC in 1966, foobar was already being commonly used as a throw-away file name. I believe fubar became foobar because the PDP-6 supported six character names, although I always assumed the term migrated to DEC from MIT. There were many MIT types at DEC in those days, some of whom had worked with the 7090/7094 CTSS. Since the 709x was also a 36 bit machine, foobar may have been used as a common file name there.

Foo and bar were also commonly used as file extensions. Since the text editors of the day operated on an input file and produced an output file, it was common to edit from a .foo file to a .bar file, and back again.

It was also common to use foo to fill a buffer when editing with TECO. The text string to exactly fill one disk block was IFOO$HXA127GA$$. Almost all of the PDP-6/10 programmers I worked with used this same command string.

Daniel P. B. Smith in 1998:

Dick Gruen had a device in his dorm room, the usual assemblage of B-battery, resistors, capacitors, and NE-2 neon tubes, which he called a "foo counter." This would have been circa 1964 or so.

Robert Schuldenfrei in 1996:

The use of FOO and BAR as example variable names goes back at least to 1964 and the IBM 7070. This too may be older, but that is where I first saw it. This was in Assembler. What would be the FORTRAN integer equivalent? IFOO and IBAR?

Paul M. Wexelblat in 1992:

The earliest PDP-1 Assembler used two characters for symbols (18 bit machine) programmers always left a few words as patch space to fix problems. (Jump to patch space, do new code, jump back) That space conventionally was named FU: which stood for Fxxx Up, the place where you fixed Fxxx Ups. When spoken, it was known as FU space. Later Assemblers ( e.g. MIDAS allowed three char tags so FU became FOO, and as ALL PDP-1 programmers will tell you that was FOO space.

Bruce B. Reynolds in 1996:

On the IBM side of FOO(FU)BAR is the use of the BAR side as Base Address Register; in the middle 1970's CICS programmers had to worry out the various xxxBARs...I think one of those was FRACTBAR...

Here's a straight IBM "BAR" from 1955.


Other early references:


I haven't been able to find any references to foo bar as "inverted foo signal" as suggested in RFC3092 and elsewhere.

Here are a some of even earlier F00s but I think they're coincidences/false positives:

Linux command (like cat) to read a specified quantity of characters

You can use dd to extract arbitrary chunks of bytes.

For example,

dd skip=1234 count=5 bs=1

would copy bytes 1235 to 1239 from its input to its output, and discard the rest.

To just get the first five bytes from standard input, do:

dd count=5 bs=1

Note that, if you want to specify the input file name, dd has old-fashioned argument parsing, so you would do:

dd count=5 bs=1 if=filename

Note also that dd verbosely announces what it did, so to toss that away, do:

dd count=5 bs=1 2>&-

or

dd count=5 bs=1 2>/dev/null

Returning value from called function in a shell script

If it's just a true/false test, have your function return 0 for success, and return 1 for failure. The test would then be:

if function_name; then
  do something
else
  error condition
fi

Dump a NumPy array into a csv file

Writing record arrays as CSV files with headers requires a bit more work.

This example reads from a CSV file ('example.csv') and writes its contents to another CSV file (out.csv).

import numpy as np

# Write an example CSV file with headers on first line
with open('example.csv', 'w') as fp:
    fp.write('''\
col1,col2,col3
1,100.1,string1
2,222.2,second string
''')

# Read it as a Numpy record array
ar = np.recfromcsv('example.csv')
print(repr(ar))
# rec.array([(1, 100.1, 'string1'), (2, 222.2, 'second string')], 
#           dtype=[('col1', '<i4'), ('col2', '<f8'), ('col3', 'S13')])

# Write as a CSV file with headers on first line
with open('out.csv', 'w') as fp:
    fp.write(','.join(ar.dtype.names) + '\n')
    np.savetxt(fp, ar, '%s', ',')

Note that the above example cannot handle values which are strings with commas. To always enclose non-numeric values within quotes, use the csv package:

import csv

with open('out2.csv', 'wb') as fp:
    writer = csv.writer(fp, quoting=csv.QUOTE_NONNUMERIC)
    writer.writerow(ar.dtype.names)
    writer.writerows(ar.tolist())

shorthand c++ if else statement

Depending on how often you use this in your code you could consider the following:

macro

#define SIGN(x) ( (x) >= 0 )

Inline function

inline int sign(int x)
{
    return x >= 0;
}

Then you would just go:

bigInt.sign = sign(number); 

When to use static methods

Static methods are the methods in Java that can be called without creating an object of class. It is belong to the class.

We use static method when we no need to be invoked method using instance.

What's the difference between '$(this)' and 'this'?

When using jQuery, it is advised to use $(this) usually. But if you know (you should learn and know) the difference, sometimes it is more convenient and quicker to use just this. For instance:

$(".myCheckboxes").change(function(){ 
    if(this.checked) 
       alert("checked"); 
});

is easier and purer than

$(".myCheckboxes").change(function(){ 
      if($(this).is(":checked")) 
         alert("checked"); 
});

Plotting a 2D heatmap with Matplotlib

Here's how to do it from a csv:

import numpy as np
import matplotlib.pyplot as plt
from scipy.interpolate import griddata

# Load data from CSV
dat = np.genfromtxt('dat.xyz', delimiter=' ',skip_header=0)
X_dat = dat[:,0]
Y_dat = dat[:,1]
Z_dat = dat[:,2]

# Convert from pandas dataframes to numpy arrays
X, Y, Z, = np.array([]), np.array([]), np.array([])
for i in range(len(X_dat)):
        X = np.append(X, X_dat[i])
        Y = np.append(Y, Y_dat[i])
        Z = np.append(Z, Z_dat[i])

# create x-y points to be used in heatmap
xi = np.linspace(X.min(), X.max(), 1000)
yi = np.linspace(Y.min(), Y.max(), 1000)

# Interpolate for plotting
zi = griddata((X, Y), Z, (xi[None,:], yi[:,None]), method='cubic')

# I control the range of my colorbar by removing data 
# outside of my range of interest
zmin = 3
zmax = 12
zi[(zi<zmin) | (zi>zmax)] = None

# Create the contour plot
CS = plt.contourf(xi, yi, zi, 15, cmap=plt.cm.rainbow,
                  vmax=zmax, vmin=zmin)
plt.colorbar()  
plt.show()

where dat.xyz is in the form

x1 y1 z1
x2 y2 z2
...

SQL Last 6 Months

In MySQL

where datetime_column > curdate() - interval (dayofmonth(curdate()) - 1) day - interval 6 month

SQLFiddle demo

In SQL Server

where datetime_column > dateadd(m, -6, getdate() - datepart(d, getdate()) + 1)

SQLFiddle demo

Ternary operators in JavaScript without an "else"

No, it needs three operands. That's why they're called ternary operators.

However, for what you have as your example, you can do this:

if(condition) x = true;

Although it's safer to have braces if you need to add more than one statement in the future:

if(condition) { x = true; }

Edit: Now that you mention the actual code in which your question applies to:

if(!defaults.slideshowWidth)
    { defaults.slideshowWidth = obj.find('img').width()+'px'; }

How to count items in JSON object using command line?

You can also use jq to track down the array within the returned json and then pipe that in to a second jq call to get its length. Suppose it was in a property called records, like {"records":[...]}.

$ curl https://my-source-of-json.com/list | jq -r '.records' | jq length
2
$ 

How do you convert CString and std::string std::wstring to each other?

It is more effecient to convert CString to std::string using the conversion where the length is specified.

CString someStr("Hello how are you");
std::string std(somStr, someStr.GetLength());

In tight loop this makes a significant performance improvement.

Can an AWS Lambda function call another

I found a way using the aws-sdk.

var aws = require('aws-sdk');
var lambda = new aws.Lambda({
  region: 'us-west-2' //change to your region
});

lambda.invoke({
  FunctionName: 'name_of_your_lambda_function',
  Payload: JSON.stringify(event, null, 2) // pass params
}, function(error, data) {
  if (error) {
    context.done('error', error);
  }
  if(data.Payload){
   context.succeed(data.Payload)
  }
});

You can find the doc here: http://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/Lambda.html

Checking oracle sid and database name

As has been mentioned above,

select global_name from global_name;

is the way to go.

You couldn't query v$database/v$instance/v$thread because your user does not have the required permissions. You can grant them (via a DBA account) with:

grant select on v$database to <username here>;

Get request URL in JSP which is forwarded by Servlet

Try this,

<c:set var="pageUrl" scope="request">
    <c:out value="${pageContext.request.scheme}://${pageContext.request.serverName}"/>
    <c:if test="${pageContext.request.serverPort != '80'}">
        <c:out value=":${pageContext.request.serverPort}"/>
    </c:if>
    <c:out value="${requestScope['javax.servlet.forward.request_uri']}"/>
</c:set>

I would like to put it in my base template and use in whole app whenever i need to.

How to load local file in sc.textFile, instead of HDFS

I tried the following and it worked from my local file system.. Basically spark can read from local, HDFS and AWS S3 path

listrdd=sc.textFile("file:////home/cloudera/Downloads/master-data/retail_db/products")

docker entrypoint running bash script gets "permission denied"

Dot [.]

This problem take with me more than 3 hours finally , I just tried the problem was in removing dot from the end just .

problem was

docker run  -p 3000:80 --rm --name test-con test-app .

/usr/local/bin/docker-entrypoint.sh: 8: exec: .: Permission denied

just remove dot from the end of your command line :

docker run  -p 3000:80 --rm --name test-con test-app 

Why, Fatal error: Class 'PHPUnit_Framework_TestCase' not found in ...?

I am using php 5.6 on window 10 with zend 1.12 version for me adding

require_once 'PHPUnit/Autoload.php';

before

abstract class Zend_Test_PHPUnit_ControllerTestCase extends PHPUnit_Framework_TestCase

worked. We need to add this above statement in ControllerTestCase.php file

Change Select List Option background colour on hover

Implementing an inset box shadow CSS works on Firefox:

select option:checked,
select option:hover {
    box-shadow: 0 0 10px 100px #000 inset;
}

Checked option item works in Chrome:

select:focus > option:checked { 
    background: #000 !important;
}

There is test on https://codepen.io/egle/pen/zzOKLe

For me this is working on Google Chrome Version 76.0.3809.100 (Official Build) (64-bit)

Newest article I have found about this issue by Chris Coyier (Oct 28, 2019) https://css-tricks.com/the-current-state-of-styling-selects-in-2019/

COLLATION 'utf8_general_ci' is not valid for CHARACTER SET 'latin1'

In my case I created a database and gave the collation 'utf8_general_ci' but the required collation was 'latin1'. After changing my collation type to latin1_bin the error was gone.

Check if xdebug is working

Without actually doing some debugging, I guess you can't be certain that a debugger is working.

But you can be pretty sure -- I guess one should assume that if some aspects of xDebug are working then it would all be working.

Given that, you can confirm that xDebug is installed and in place by trying the following:

1) phpinfo() -- this will show you all the extensions that are loaded, including xDebug. If it is there, then it's a safe bet that it's working.

2) If that isn't good enough for you, you can try using the var_dump() function. xDebug modifies the output of var_dump() to include additional information. If this is in place, then xDebug is working.

3) xDebug modifies PHP's error output. If your program crashes with xDebug in place, you'll get more information about the failure than with the standard PHP crash output.

4) xDebug also adds a number of helper functions to PHP. You could try any of these to see if it's working. For example, the function xdebug_get_code_coverage() should exist and return an array. If it does, then xDebug is installed. If not, it isn't.

Formatting Decimal places in R

You can format a number, say x, up to decimal places as you wish. Here x is a number with many decimal places. Suppose we wish to show up to 8 decimal places of this number:

x = 1111111234.6547389758965789345
y = formatC(x, digits = 8, format = "f")
# [1] "1111111234.65473890"

Here format="f" gives floating numbers in the usual decimal places say, xxx.xxx, and digits specifies the number of digits. By contrast, if you wanted to get an integer to display you would use format="d" (much like sprintf).

When should I use Lazy<T>?

You typically use it when you want to instantiate something the first time its actually used. This delays the cost of creating it till if/when it's needed instead of always incurring the cost.

Usually this is preferable when the object may or may not be used and the cost of constructing it is non-trivial.

How should I deal with "package 'xxx' is not available (for R version x.y.z)" warning?

11. R (or another dependency) is out of date and you don't want to update it.

Warning this is not exactly best practice.

  • Download the package source.
  • Navigate to the DESCRIPTION file.
  • Remove the offending line with your text editor e.g.

    Depends: R (>= 3.1.1)
    
  • Install from local (i.e. from the parent directory of DESCRIPTION) e.g.

    install.packages("foo", type="source", repos=NULL)
    

Combine multiple Collections into a single logical Collection?

Plain Java 8 solutions using a Stream.

Constant number

Assuming private Collection<T> c, c2, c3.

One solution:

public Stream<T> stream() {
    return Stream.concat(Stream.concat(c.stream(), c2.stream()), c3.stream());
}

Another solution:

public Stream<T> stream() {
    return Stream.of(c, c2, c3).flatMap(Collection::stream);
}

Variable number

Assuming private Collection<Collection<T>> cs:

public Stream<T> stream() {
    return cs.stream().flatMap(Collection::stream);
}

How to add a browser tab icon (favicon) for a website?

  1. Use a tool to convert your png to a ico file. You can search "favicon generator" and you can find many online tools.
  2. Place the ico address in the head with a link-tag:

    <link rel="shortcut icon" href="http://sstatic.net/stackoverflow/img/favicon.ico">
    

Using JavaMail with TLS

Good post, the line

props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

is mandatory if the SMTP server uses SSL Authentication, like the GMail SMTP server does. However if the server uses Plaintext Authentication over TLS, it should not be present, because Java Mail will complain about the initial connection being plaintext.

Also make sure you are using the latest version of Java Mail. Recently I used some old Java Mail jars from a previous project and could not make the code work, because the login process was failing. After I have upgraded to the latest version of Java Mail, the reason of the error became clear: it was a javax.net.ssl.SSLHandshakeException, which was not thrown up in the old version of the lib.

C# Change A Button's Background Color

Code for set background color, for SolidColor:

button.Background = new SolidColorBrush(Color.FromArgb(Avalue, rValue, gValue, bValue));

Is there a way to make text unselectable on an HTML page?

There are many occasions when turning off selectability enhances the user experience.

For instance allowing the user to copy a block of text on the page without copying the text of any interface elements associated with it (that would become interspersed within the text being copied).

How to implement endless list with RecyclerView?

My way to detect loading event is not to detect scrolling, but to listen whether the last view was attached. If the last view was attached, I regard it as timing to load more content.

class MyListener implements RecyclerView.OnChildAttachStateChangeListener {
    RecyclerView mRecyclerView;

    MyListener(RecyclerView view) {
        mRecyclerView = view;
    }

    @Override
    public void onChildViewAttachedToWindow(View view) {

    RecyclerView.Adapter adapter = mRecyclerView.getAdapter();
    RecyclerView.LayoutManager mgr = mRecyclerView.getLayoutManager();
    int adapterPosition = mgr.getPosition(view);

    if (adapterPosition == adapter.getItemCount() - 1) {
        // last view was attached
        loadMoreContent();
    }

    @Override
    public void onChildViewDetachedFromWindow(View view) {}
}

If statement within Where clause

CASE might help you out:

SELECT t.first_name,
       t.last_name,
       t.employid,
       t.status
  FROM employeetable t
 WHERE t.status = (CASE WHEN status_flag = STATUS_ACTIVE THEN 'A'
                        WHEN status_flag = STATUS_INACTIVE THEN 'T'
                        ELSE null END)
   AND t.business_unit = (CASE WHEN source_flag = SOURCE_FUNCTION THEN 'production'
                               WHEN source_flag = SOURCE_USER THEN 'users'
                               ELSE null END)
   AND t.first_name LIKE firstname
   AND t.last_name LIKE lastname
   AND t.employid LIKE employeeid;

The CASE statement evaluates multiple conditions to produce a single value. So, in the first usage, I check the value of status_flag, returning 'A', 'T' or null depending on what it's value is, and compare that to t.status. I do the same for the business_unit column with a second CASE statement.

not None test in Python

if val is not None:
    # ...

is the Pythonic idiom for testing that a variable is not set to None. This idiom has particular uses in the case of declaring keyword functions with default parameters. is tests identity in Python. Because there is one and only one instance of None present in a running Python script/program, is is the optimal test for this. As Johnsyweb points out, this is discussed in PEP 8 under "Programming Recommendations".

As for why this is preferred to

if not (val is None):
    # ...

this is simply part of the Zen of Python: "Readability counts." Good Python is often close to good pseudocode.

convert streamed buffers to utf8-string

var fs = require("fs");

function readFileLineByLine(filename, processline) {
    var stream = fs.createReadStream(filename);
    var s = "";
    stream.on("data", function(data) {
        s += data.toString('utf8');
        var lines = s.split("\n");
        for (var i = 0; i < lines.length - 1; i++)
            processline(lines[i]);
        s = lines[lines.length - 1];
    });

    stream.on("end",function() {
        var lines = s.split("\n");
        for (var i = 0; i < lines.length; i++)
            processline(lines[i]);
    });
}

var linenumber = 0;
readFileLineByLine(filename, function(line) {
    console.log(++linenumber + " -- " + line);
});

Delete many rows from a table using id in Mysql

DELETE FROM table_name WHERE id BETWEEN 1 AND 256;

Try This.

How can I update a row in a DataTable in VB.NET?

The problem you're running into is that you're trying to replace an entire row object. That is not allowed by the DataTable API. Instead you have to update the values in the columns of a row object. Or add a new row to the collection.

To update the column of a particular row you can access it by name or index. For instance you could write the following code to update the column "Foo" to be the value strVerse

dtResult.Rows(i)("Foo") = strVerse

Convert Map<String,Object> to Map<String,String>

Great solutions here, just one more option that taking into consideration handling of null values:

Map<String,Object> map = new HashMap<>();

Map<String,String> stringifiedMap = map.entrySet().stream()
             .filter(m -> m.getKey() != null && m.getValue() !=null)
             .collect(Collectors.toMap(Map.Entry::getKey, e -> (String)e.getValue()));

Git - fatal: Unable to create '/path/my_project/.git/index.lock': File exists

In Windows, I only managed to be able to delete the lock file after Ending Task for all Git Windows (32bit) processes in the Task Manager.

Solution (Win 10)

1. End Task for all Git Windows (32bit) processes in the Task Manager

2. Delete the .git/index.lock file

"installation of package 'FILE_PATH' had non-zero exit status" in R

For those of you who are using MacOS and like me perhaps have been circling the internet as to why some R packages do not install here is a possible help.

If you get a non-zero exit status first check to ensure all dependencies are installed as well. Read through the messaging. If that is checked off, then look for indications such as gfortran: No such a file or directory. That might be due to Apple OS compiler issues that some packages will not install unless you use their binary version. Look for binary zip file in the package cran.r-project.org page, download it and use the following command to get the package installed:

install.packages("/PATH/zip file ", repos = NULL, type="source")

Get all object attributes in Python?

What you probably want is dir().

The catch is that classes are able to override the special __dir__ method, which causes dir() to return whatever the class wants (though they are encouraged to return an accurate list, this is not enforced). Furthermore, some objects may implement dynamic attributes by overriding __getattr__, may be RPC proxy objects, or may be instances of C-extension classes. If your object is one these examples, they may not have a __dict__ or be able to provide a comprehensive list of attributes via __dir__: many of these objects may have so many dynamic attrs it doesn't won't actually know what it has until you try to access it.

In the short run, if dir() isn't sufficient, you could write a function which traverses __dict__ for an object, then __dict__ for all the classes in obj.__class__.__mro__; though this will only work for normal python objects. In the long run, you may have to use duck typing + assumptions - if it looks like a duck, cross your fingers, and hope it has .feathers.

Is there an addHeaderView equivalent for RecyclerView?

There is one more solution that covers all the use cases above: CompoundAdapter: https://github.com/negusoft/CompoundAdapter-android

You can create a AdapterGroup that holds your Adapter as it is, along with an adapter with a single item to represent the header. The code is easy and readable:

AdapterGroup adapterGroup = new AdapterGroup();
adapterGroup.addAdapter(SingleAdapter.create(R.layout.header));
adapterGroup.addAdapter(new CommentAdapter(...));

recyclerView.setAdapter(adapterGroup);

AdapterGroup allows nesting too, so for a adapter with sections, you may create a AdapterGroup per section. Then put all the sections in a root AdapterGroup.

Detect Close windows event by jQuery

You can use:

$(window).unload(function() {
    //do something
}

Unload() is deprecated in jQuery version 1.8, so if you use jQuery > 1.8 you can use even beforeunload instead.

The beforeunload event fires whenever the user leaves your page for any reason.

$(window).on("beforeunload", function() { 
    return confirm("Do you really want to close?"); 
})

Source Browser window close event

How to calculate md5 hash of a file using javascript

The following snippet shows an example, which can archive a throughput of 400 MB/s while reading and hashing the file.

It is using a library called hash-wasm, which is based on WebAssembly and calculates the hash faster than js-only libraries. As of 2020, all modern browsers support WebAssembly.

_x000D_
_x000D_
const chunkSize = 64 * 1024 * 1024;
const fileReader = new FileReader();
let hasher = null;

function hashChunk(chunk) {
  return new Promise((resolve, reject) => {
    fileReader.onload = async(e) => {
      const view = new Uint8Array(e.target.result);
      hasher.update(view);
      resolve();
    };

    fileReader.readAsArrayBuffer(chunk);
  });
}

const readFile = async(file) => {
  if (hasher) {
    hasher.init();
  } else {
    hasher = await hashwasm.createMD5();
  }

  const chunkNumber = Math.floor(file.size / chunkSize);

  for (let i = 0; i <= chunkNumber; i++) {
    const chunk = file.slice(
      chunkSize * i,
      Math.min(chunkSize * (i + 1), file.size)
    );
    await hashChunk(chunk);
  }

  const hash = hasher.digest();
  return Promise.resolve(hash);
};

const fileSelector = document.getElementById("file-input");
const resultElement = document.getElementById("result");

fileSelector.addEventListener("change", async(event) => {
  const file = event.target.files[0];

  resultElement.innerHTML = "Loading...";
  const start = Date.now();
  const hash = await readFile(file);
  const end = Date.now();
  const duration = end - start;
  const fileSizeMB = file.size / 1024 / 1024;
  const throughput = fileSizeMB / (duration / 1000);
  resultElement.innerHTML = `
    Hash: ${hash}<br>
    Duration: ${duration} ms<br>
    Throughput: ${throughput.toFixed(2)} MB/s
  `;
});
_x000D_
<script src="https://cdn.jsdelivr.net/npm/hash-wasm"></script>
<!-- defines the global `hashwasm` variable -->

<input type="file" id="file-input">
<div id="result"></div>
_x000D_
_x000D_
_x000D_

Develop Android app using C#

You could use Mono for Android:

http://xamarin.com/monoforandroid

An alternative is dot42:

http://www.dot42.com/

dot42 provides a free community licence as well as a professional licence for $399.

How do I set the default value for an optional argument in Javascript?

If str is null, undefined or 0, this code will set it to "hai"

function(nodeBox, str) {
  str = str || "hai";
.
.
.

If you also need to pass 0, you can use:

function(nodeBox, str) {
  if (typeof str === "undefined" || str === null) { 
    str = "hai"; 
  }
.
.
.

how to fetch data from database in Hibernate

Query query = session.createQuery("from Employee");

Note: from Employee. here Employee is not your table name it's POJO name.

How to get response status code from jQuery.ajax?

When your XHR request returns a Redirect response (HTTP Status 301, 302, 303, 307), the XMLHttpRequest automatically follows the redirected URL and returns the status code of that URL.

You can get the non-redirecting status codes (200, 400, 500 etc) via the status property of the xhr object.

So you cannot get the redirected location from the response header of a 301, 302, 303 or 307 request.

You might have to change your server logic to respond in a way that you can handle the redirect, rather than letting the browser do it. An example implementation.

How to save picture to iPhone photo library?

You can use this function:

UIImageWriteToSavedPhotosAlbum(UIImage *image, 
                               id completionTarget, 
                               SEL completionSelector, 
                               void *contextInfo);

You only need completionTarget, completionSelector and contextInfo if you want to be notified when the UIImage is done saving, otherwise you can pass in nil.

See the official documentation for UIImageWriteToSavedPhotosAlbum().

Vector of structs initialization

You may also which to use aggregate initialization from a braced initialization list for situations like these.

#include <vector>
using namespace std;

struct subject {
    string name;
    int    marks;
    int    credits;
};

int main() {
    vector<subject> sub {
      {"english", 10, 0},
      {"math"   , 20, 5}
    };
}

Sometimes however, the members of a struct may not be so simple, so you must give the compiler a hand in deducing its types.

So extending on the above.

#include <vector>
using namespace std;

struct assessment {
    int   points;
    int   total;
    float percentage;
};

struct subject {
    string name;
    int    marks;
    int    credits;
    vector<assessment> assessments;
};

int main() {
    vector<subject> sub {
      {"english", 10, 0, {
                             assessment{1,3,0.33f},
                             assessment{2,3,0.66f},
                             assessment{3,3,1.00f}
                         }},
      {"math"   , 20, 5, {
                             assessment{2,4,0.50f}
                         }}
    };
}

Without the assessment in the braced initializer the compiler will fail when attempting to deduce the type.

The above has been compiled and tested with gcc in c++17. It should however work from c++11 and onward. In c++20 we may see the designator syntax, my hope is that it will allow for for the following

  {"english", 10, 0, .assessments{
                         {1,3,0.33f},
                         {2,3,0.66f},
                         {3,3,1.00f}
                     }},

source: http://en.cppreference.com/w/cpp/language/aggregate_initialization

Plotting images side by side using matplotlib

As per matplotlib's suggestion for image grids:

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import ImageGrid

fig = plt.figure(figsize=(4., 4.))
grid = ImageGrid(fig, 111,  # similar to subplot(111)
                 nrows_ncols=(2, 2),  # creates 2x2 grid of axes
                 axes_pad=0.1,  # pad between axes in inch.
                 )

for ax, im in zip(grid, image_data):
    # Iterating over the grid returns the Axes.
    ax.imshow(im)

plt.show()

How do I format my oracle queries so the columns don't wrap?

Never mind, figured it out:

set wrap off
set linesize 3000 -- (or to a sufficiently large value to hold your results page)

Which I found by:

show all

And looking for some option that seemed relevant.

Get UTC time and local time from NSDate object

NSDate is a specific point in time without a time zone. Think of it as the number of seconds that have passed since a reference date. How many seconds have passed in one time zone vs. another since a particular reference date? The answer is the same.

Depending on how you output that date (including looking at the debugger), you may get an answer in a different time zone.

If they ran at the same moment, the values of these are the same. They're both the number of seconds since the reference date, which may be formatted on output to UTC or local time. Within the date variable, they're both UTC.

Objective-C:

NSDate *UTCDate = [NSDate date]

Swift:

let UTCDate = NSDate.date()

To explain this, we can use a NSDateFormatter in a playground:

import UIKit

let date = NSDate.date()
    // "Jul 23, 2014, 11:01 AM" <-- looks local without seconds. But:

var formatter = NSDateFormatter()
formatter.dateFormat = "yyyy-MM-dd HH:mm:ss ZZZ"
let defaultTimeZoneStr = formatter.stringFromDate(date)
    // "2014-07-23 11:01:35 -0700" <-- same date, local, but with seconds
formatter.timeZone = NSTimeZone(abbreviation: "UTC")
let utcTimeZoneStr = formatter.stringFromDate(date)
    // "2014-07-23 18:01:41 +0000" <-- same date, now in UTC

The date output varies, but the date is constant. This is exactly what you're saying. There's no such thing as a local NSDate.

As for how to get microseconds out, you can use this (put it at the bottom of the same playground):

let seconds = date.timeIntervalSince1970
let microseconds = Int(seconds * 1000) % 1000 // chops off seconds

To compare two dates, you can use date.compare(otherDate).

How to hide axes and gridlines in Matplotlib (python)

Turn the axes off with:

plt.axis('off')

And gridlines with:

plt.grid(b=None)

Extract digits from a string in Java

Use regular expression to match your requirement.

String num,num1,num2;
String str = "123-456-789";
String regex ="(\\d+)";
Matcher matcher = Pattern.compile( regex ).matcher( str);
while (matcher.find( ))
{
num = matcher.group();     
System.out.print(num);                 
}

Append to the end of a file in C

Following the documentation of fopen:

``a'' Open for writing. The file is created if it does not exist. The stream is positioned at the end of the file. Subsequent writes to the file will always end up at the then cur- rent end of file, irrespective of any intervening fseek(3) or similar.

So if you pFile2=fopen("myfile2.txt", "a"); the stream is positioned at the end to append automatically. just do:

FILE *pFile;
FILE *pFile2;
char buffer[256];

pFile=fopen("myfile.txt", "r");
pFile2=fopen("myfile2.txt", "a");
if(pFile==NULL) {
    perror("Error opening file.");
}
else {
    while(fgets(buffer, sizeof(buffer), pFile)) {
        fprintf(pFile2, "%s", buffer);
    }
}
fclose(pFile);
fclose(pFile2);

Converting Float to Dollars and Cents

you said that:

`mony = float(1234.5)
print(money)      #output is 1234.5
'${:,.2f}'.format(money)
print(money)

did not work.... Have you coded exactly that way? This should work (see the little difference):

money = float(1234.5)      #next you used format without printing, nor affecting value of "money"
amountAsFormattedString = '${:,.2f}'.format(money)
print( amountAsFormattedString )

How to convert Moment.js date to users local timezone?

Use utcOffset function.

var testDateUtc = moment.utc("2015-01-30 10:00:00");
var localDate = moment(testDateUtc).utcOffset(10 * 60); //set timezone offset in minutes
console.log(localDate.format()); //2015-01-30T20:00:00+10:00

SQL to find the number of distinct values in a column

**

Using following SQL we can get the distinct column value count in Oracle 11g.

**

Select count(distinct(Column_Name)) from TableName

Search a whole table in mySQL for a string

for specific requirement the following will work for search:

select * from table_name where (column_name1='%var1%' or column_name2='var2' or column_name='%var3%') and column_name='var';

if you want to query for searching data from the database this will work perfectly.

Change variable name in for loop using R

Another option is using eval and parse, as in

d = 5
for (i in 1:10){
     eval(parse(text = paste('a', 1:10, ' = d + rnorm(3)', sep='')[i]))
}

How to loop through file names returned by find?

If you can assume the file names don't contain newlines, you can read the output of find into a Bash array using the following command:

readarray -t x < <(find . -name '*.txt')

Note:

  • -t causes readarray to strip newlines.
  • It won't work if readarray is in a pipe, hence the process substitution.
  • readarray is available since Bash 4.

Bash 4.4 and up also supports the -d parameter for specifying the delimiter. Using the null character, instead of newline, to delimit the file names works also in the rare case that the file names contain newlines:

readarray -d '' x < <(find . -name '*.txt' -print0)

readarray can also be invoked as mapfile with the same options.

Reference: https://mywiki.wooledge.org/BashFAQ/005#Loading_lines_from_a_file_or_stream

Passing arguments to AsyncTask, and returning results

I dont do it like this. I find it easier to overload the constructor of the asychtask class ..

public class calc_stanica extends AsyncTask>

String String mWhateveryouwantToPass;

 public calc_stanica( String whateveryouwantToPass)
{

    this.String mWhateveryouwantToPass = String whateveryouwantToPass;
}
/*Now you can use  whateveryouwantToPass in the entire asynchTask ... you could pass in a context to your activity and try that too.*/   ...  ...  

How to import XML file into MySQL database table using XML_LOAD(); function

you can specify fields like this:

LOAD XML LOCAL INFILE '/pathtofile/file.xml' 
INTO TABLE my_tablename(personal_number, firstname, ...); 

Sort a List of Object in VB.NET

try..

Dim sortedList = From entry In mylist Order By entry.name Ascending Select entry

mylist = sortedList.ToList

Radio button checked event handling

You can simply use the method change of JQuery to get the value of the current radio checked with the following code:

$(document).on('change', '[type="radio"]', function() {
    var currentlyValue = $(this).val(); // Get the radio checked value
        
    alert('Currently value: '+currentlyValue); // Show a alert with the current value
});

You can change the selector '[type="radio"]' for a class or id that you want.

Eclipse CDT: Symbol 'cout' could not be resolved

I tried the marked solution here first. It worked but it is kind hacky, and you need to redo it every time you update the gcc. I finally find a better solution by doing the followings:

  1. Project -> Properties -> C/C++ General -> Preprocessor Include Paths, Macros, etc.
  2. Providers -> CDT GCC built-in compiler settings
  3. Uncheck Use global provider shared between projects (you can also modify the global provider if it fits your need)
  4. In Command to get compiler specs, add -std=c++11 at the end
  5. Index->Rebuild

Voila, easy and simple. Hopefully this helps.

Note: I am on Kepler. I am not sure if this works on earlier Eclipse.

How can I convert an image into a Base64 string?

This code runs perfect in my project:

profile_image.buildDrawingCache();
Bitmap bmap = profile_image.getDrawingCache();
String encodedImageData = getEncoded64ImageStringFromBitmap(bmap);


public String getEncoded64ImageStringFromBitmap(Bitmap bitmap) {
    ByteArrayOutputStream stream = new ByteArrayOutputStream();
    bitmap.compress(CompressFormat.JPEG, 70, stream);
    byte[] byteFormat = stream.toByteArray();

    // Get the Base64 string
    String imgString = Base64.encodeToString(byteFormat, Base64.NO_WRAP);

    return imgString;
}

How to access share folder in virtualbox. Host Win7, Guest Fedora 16?

You probably need to change your mount command from:

[root@localhost Desktop]# sudo mount -t vboxsf D:\share_folder_vm \share_folder

to:

[root@localhost Desktop]# sudo mount -t vboxsf share_name \share_folder

where share_name is the "Name" of the share in the VirtualBox -> Shared Folders -> Folder List list box. The argument you have ("D:\share_folder_vm") is the "Path" of the share on the host, not the "Name".

jQuery AJAX form data serialize using PHP

Try this its working..

    <script>
      $(function () {
          $('form').on('submit', function (e) {
              e.preventDefault();
              $.ajax({
                  type: 'post',
                  url: '<?php echo base_url();?>student_ajax/insert',
                  data: $('form').serialize(),
                  success: function (response) {
                      alert('form was submitted');
                  }
                  error:function() {
                      alert('fail');
                  }
              });
          });
      });
    </script>

Getting the absolute path of the executable, using C#?

On my side, I used, with a form application:

String Directory = System.Windows.Forms.Application.StartupPath;

it takes the application startup path.

Getting the last element of a split string array

array.split(' ').slice(-1)[0]

The best one ever and my favorite.

d3 add text to circle

Extended the example above to fit the actual requirements, where circled is filled with solid background color, then with striped pattern & after that text node is placed on the center of the circle.

_x000D_
_x000D_
var width = 960,_x000D_
  height = 500,_x000D_
  json = {_x000D_
    "nodes": [{_x000D_
      "x": 100,_x000D_
      "r": 20,_x000D_
      "label": "Node 1",_x000D_
      "color": "red"_x000D_
    }, {_x000D_
      "x": 200,_x000D_
      "r": 25,_x000D_
      "label": "Node 2",_x000D_
      "color": "blue"_x000D_
    }, {_x000D_
      "x": 300,_x000D_
      "r": 30,_x000D_
      "label": "Node 3",_x000D_
      "color": "green"_x000D_
    }]_x000D_
  };_x000D_
_x000D_
var svg = d3.select("body").append("svg")_x000D_
  .attr("width", width)_x000D_
  .attr("height", height)_x000D_
_x000D_
svg.append("defs")_x000D_
  .append("pattern")_x000D_
  .attr({_x000D_
    "id": "stripes",_x000D_
    "width": "8",_x000D_
    "height": "8",_x000D_
    "fill": "red",_x000D_
    "patternUnits": "userSpaceOnUse",_x000D_
    "patternTransform": "rotate(60)"_x000D_
  })_x000D_
  .append("rect")_x000D_
  .attr({_x000D_
    "width": "4",_x000D_
    "height": "8",_x000D_
    "transform": "translate(0,0)",_x000D_
    "fill": "grey"_x000D_
  });_x000D_
_x000D_
function plotChart(json) {_x000D_
  /* Define the data for the circles */_x000D_
  var elem = svg.selectAll("g myCircleText")_x000D_
    .data(json.nodes)_x000D_
_x000D_
  /*Create and place the "blocks" containing the circle and the text */_x000D_
  var elemEnter = elem.enter()_x000D_
    .append("g")_x000D_
    .attr("class", "node-group")_x000D_
    .attr("transform", function(d) {_x000D_
      return "translate(" + d.x + ",80)"_x000D_
    })_x000D_
_x000D_
  /*Create the circle for each block */_x000D_
  var circleInner = elemEnter.append("circle")_x000D_
    .attr("r", function(d) {_x000D_
      return d.r_x000D_
    })_x000D_
    .attr("stroke", function(d) {_x000D_
      return d.color;_x000D_
    })_x000D_
    .attr("fill", function(d) {_x000D_
      return d.color;_x000D_
    });_x000D_
_x000D_
  var circleOuter = elemEnter.append("circle")_x000D_
    .attr("r", function(d) {_x000D_
      return d.r_x000D_
    })_x000D_
    .attr("stroke", function(d) {_x000D_
      return d.color;_x000D_
    })_x000D_
    .attr("fill", "url(#stripes)");_x000D_
_x000D_
  /* Create the text for each block */_x000D_
  elemEnter.append("text")_x000D_
    .text(function(d) {_x000D_
      return d.label_x000D_
    })_x000D_
    .attr({_x000D_
      "text-anchor": "middle",_x000D_
      "font-size": function(d) {_x000D_
        return d.r / ((d.r * 10) / 100);_x000D_
      },_x000D_
      "dy": function(d) {_x000D_
        return d.r / ((d.r * 25) / 100);_x000D_
      }_x000D_
    });_x000D_
};_x000D_
_x000D_
plotChart(json);
_x000D_
.node-group {_x000D_
  fill: #ffffff;_x000D_
}
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>
_x000D_
_x000D_
_x000D_

Output:

enter image description here

Below is the link to codepen also:

See the Pen D3-Circle-Pattern-Text by Manish Kumar (@mkdudeja) on CodePen.

Thanks, Manish Kumar

Uncaught TypeError: (intermediate value)(...) is not a function

To make semicolon rules simple

Every line that begins with a (, [, `, or any operator (/, +, - are the only valid ones), must begin with a semicolon.

func()
;[0].concat(myarr).forEach(func)
;(myarr).forEach(func)
;`hello`.forEach(func)
;/hello/.exec(str)
;+0
;-0

This prevents a

func()[0].concat(myarr).forEach(func)(myarr).forEach(func)`hello`.forEach(func)/hello/.forEach(func)+0-0

monstrocity.

Additional Note

To mention what will happen: brackets will index, parentheses will be treated as function parameters. The backtick would transform into a tagged template, and regex or explicitly signed integers will turn into operators. Of course, you can just add a semicolon to the end of every line. It's good to keep mind though when you're quickly prototyping and are dropping your semicolons.

Also, adding semicolons to the end of every line won't help you with the following, so keep in mind statements like

return // Will automatically insert semicolon, and return undefined.
    (1+2);
i // Adds a semicolon
   ++ // But, if you really intended i++ here, your codebase needs help.

The above case will happen to return/continue/break/++/--. Any linter will catch this with dead-code or ++/-- syntax error (++/-- will never realistically happen).

Finally, if you want file concatenation to work, make sure each file ends with a semicolon. If you're using a bundler program (recommended), it should do this automatically.

Find and replace - Add carriage return OR Newline

Just a minor word of warning... a lot of environments use, or need, "\r\n" and not just "\n". I ran into an issue with Visual Studio not matching my regex string at the end of the line because I left off the "\r" of "\r\n", so my string couldn't match with a missing invisible character.

So, if you are doing a find, or a replace, consider the "\r".

For a little more detail on "\r" and "\n", see: https://stackoverflow.com/a/3451192/4427457

How do you add a Dictionary of items into another Dictionary

My needs were different, I needed to merge incomplete nested data sets without clobbering.

merging:
    ["b": [1, 2], "s": Set([5, 6]), "a": 1, "d": ["x": 2]]
with
    ["b": [3, 4], "s": Set([6, 7]), "a": 2, "d": ["y": 4]]
yields:
    ["b": [1, 2, 3, 4], "s": Set([5, 6, 7]), "a": 2, "d": ["y": 4, "x": 2]]

This was harder than I wanted it to be. The challenge was in mapping from dynamic typing to static typing, and I used protocols to solve this.

Also worthy of note is that when you use the dictionary literal syntax, you actually get the foundation types, which do not pick up the protocol extensions. I aborted my efforts to support those as I couldn't find an easy to to validate the uniformity of the collection elements.

import UIKit


private protocol Mergable {
    func mergeWithSame<T>(right: T) -> T?
}



public extension Dictionary {

    /**
    Merge Dictionaries

    - Parameter left: Dictionary to update
    - Parameter right:  Source dictionary with values to be merged

    - Returns: Merged dictionay
    */


    func merge(right:Dictionary) -> Dictionary {
        var merged = self
        for (k, rv) in right {

            // case of existing left value
            if let lv = self[k] {

                if let lv = lv as? Mergable where lv.dynamicType == rv.dynamicType {
                    let m = lv.mergeWithSame(rv)
                    merged[k] = m
                }

                else if lv is Mergable {
                    assert(false, "Expected common type for matching keys!")
                }

                else if !(lv is Mergable), let _ = lv as? NSArray {
                    assert(false, "Dictionary literals use incompatible Foundation Types")
                }

                else if !(lv is Mergable), let _ = lv as? NSDictionary {
                    assert(false, "Dictionary literals use incompatible Foundation Types")
                }

                else {
                    merged[k] = rv
                }
            }

                // case of no existing value
            else {
                merged[k] = rv
            }
        }

        return merged
    }
}




extension Array: Mergable {

    func mergeWithSame<T>(right: T) -> T? {

        if let right = right as? Array {
            return (self + right) as? T
        }

        assert(false)
        return nil
    }
}


extension Dictionary: Mergable {

    func mergeWithSame<T>(right: T) -> T? {

        if let right = right as? Dictionary {
            return self.merge(right) as? T
        }

        assert(false)
        return nil
    }
}


extension Set: Mergable {

    func mergeWithSame<T>(right: T) -> T? {

        if let right = right as? Set {
            return self.union(right) as? T
        }

        assert(false)
        return nil
    }
}



var dsa12 = Dictionary<String, Any>()
dsa12["a"] = 1
dsa12["b"] = [1, 2]
dsa12["s"] = Set([5, 6])
dsa12["d"] = ["c":5, "x": 2]


var dsa34 = Dictionary<String, Any>()
dsa34["a"] = 2
dsa34["b"] = [3, 4]
dsa34["s"] = Set([6, 7])
dsa34["d"] = ["c":-5, "y": 4]


//let dsa2 = ["a": 1, "b":a34]
let mdsa3 = dsa12.merge(dsa34)
print("merging:\n\t\(dsa12)\nwith\n\t\(dsa34) \nyields: \n\t\(mdsa3)")

Is there a "standard" format for command line/shell help text?

Microsoft has their own Command Line Standard specification:

This document is focused at developers of command line utilities. Collectively, our goal is to present a consistent, composable command line user experience. Achieving that allows a user to learn a core set of concepts (syntax, naming, behaviors, etc) and then be able to translate that knowledge into working with a large set of commands. Those commands should be able to output standardized streams of data in a standardized format to allow easy composition without the burden of parsing streams of output text. This document is written to be independent of any specific implementation of a shell, set of utilities or command creation technologies; however, Appendix J - Using Windows Powershell to implement the Microsoft Command Line Standard shows how using Windows PowerShell will provide implementation of many of these guidelines for free.

how to read a text file using scanner in Java?

If you are working in some IDE like Eclipse or NetBeans, you should have that a.txt file in the root directory of your project. (and not in the folder where your .class files are built or anywhere else)

If not, you should specify the absolute path to that file.


Edit:
You would put the .txt file in the same place with the .class(usually also the .java file because you compile in the same folder) compiled files if you compile it by hand with javac. This is because it uses the relative path and the path tells the JVM the path where the executable file is located.

If you use some IDE, it will generate the compiled files for you using a Makefile or something similar for Windows and will consider it's default file structure, so he knows that the relative path begins from the root folder of the project.

iPhone hide Navigation Bar only on first page

By implement this code in your ViewController you can get this effect Actually the trick is , hide the navigationBar when that Controller is launched

- (void)viewWillAppear:(BOOL)animated {
    [self.navigationController setNavigationBarHidden:YES animated:YES];
    [super viewWillAppear:animated];
}

and unhide the navigation bar when user leave that page do this is viewWillDisappear

- (void)viewWillDisappear:(BOOL)animated {
    [self.navigationController setNavigationBarHidden:NO animated:YES];
    [super viewWillDisappear:animated];
}

Find files containing a given text

Just to include one more alternative, you could also use this:

find "/starting/path" -type f -regextype posix-extended -regex "^.*\.(php|html|js)$" -exec grep -EH '(document\.cookie|setcookie)' {} \;

Where:

  • -regextype posix-extended tells find what kind of regex to expect
  • -regex "^.*\.(php|html|js)$" tells find the regex itself filenames must match
  • -exec grep -EH '(document\.cookie|setcookie)' {} \; tells find to run the command (with its options and arguments) specified between the -exec option and the \; for each file it finds, where {} represents where the file path goes in this command.

    while

    • E option tells grep to use extended regex (to support the parentheses) and...
    • H option tells grep to print file paths before the matches.

And, given this, if you only want file paths, you may use:

find "/starting/path" -type f -regextype posix-extended -regex "^.*\.(php|html|js)$" -exec grep -EH '(document\.cookie|setcookie)' {} \; | sed -r 's/(^.*):.*$/\1/' | sort -u

Where

  • | [pipe] send the output of find to the next command after this (which is sed, then sort)
  • r option tells sed to use extended regex.
  • s/HI/BYE/ tells sed to replace every First occurrence (per line) of "HI" with "BYE" and...
  • s/(^.*):.*$/\1/ tells it to replace the regex (^.*):.*$ (meaning a group [stuff enclosed by ()] including everything [.* = one or more of any-character] from the beginning of the line [^] till' the first ':' followed by anything till' the end of line [$]) by the first group [\1] of the replaced regex.
  • u tells sort to remove duplicate entries (take sort -u as optional).

...FAR from being the most elegant way. As I said, my intention is to increase the range of possibilities (and also to give more complete explanations on some tools you could use).

XML Carriage return encoding

To insert a CR into XML, you need to use its character entity &#13;.

This is because compliant XML parsers must, before parsing, translate CRLF and any CR not followed by a LF to a single LF. This behavior is defined in the End-of-Line handling section of the XML 1.0 specification.

Running Python on Windows for Node.js dependencies

This helped: https://www.npmjs.com/package/node-gyp

I followed these steps:

npm install -g node-gyp

then:

npm install --global --production windows-build-tools

Is there a way to get colored text in GitHubflavored Markdown?

You can not color plain text in a GitHub README.md file. You can however add color to code samples in your GitHub README.md file with the tags below.

To do this, just add tags, such as these samples, to your README.md file:

```json
   // Code for coloring
```
```html
   // Code for coloring
```
```js
   // Code for coloring
```
```css
   // Code for coloring
```
// etc.

**Colored Code Example, JavaScript:** place this code below, in your GitHub README.md file and see how it colors the code for you.
  import { Component } from '@angular/core';
  import { MovieService } from './services/movie.service';

  @Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css'],
    providers: [ MovieService ]
  })
  export class AppComponent {
    title = 'app works!';
  }

No "pre" or "code" tags are needed.

This is now covered in the GitHub Markdown documentation (about half way down the page, there's an example using Ruby). GitHub uses Linguist to identify and highlight syntax - you can find a full list of supported languages (as well as their markdown keywords) over in the Linguist's YAML file.

DEMO

How to round a floating point number up to a certain decimal place?

This is normal (and has nothing to do with Python) because 8.83 cannot be represented exactly as a binary float, just as 1/3 cannot be represented exactly in decimal (0.333333... ad infinitum).

If you want to ensure absolute precision, you need the decimal module:

>>> import decimal
>>> a = decimal.Decimal("8.833333333339")
>>> print(round(a,2))
8.83

How to unpack pkl file?

In case you want to work with the original MNIST files, here is how you can deserialize them.

If you haven't downloaded the files yet, do that first by running the following in the terminal:

wget http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz
wget http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz
wget http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz
wget http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz

Then save the following as deserialize.py and run it.

import numpy as np
import gzip

IMG_DIM = 28

def decode_image_file(fname):
    result = []
    n_bytes_per_img = IMG_DIM*IMG_DIM

    with gzip.open(fname, 'rb') as f:
        bytes_ = f.read()
        data = bytes_[16:]

        if len(data) % n_bytes_per_img != 0:
            raise Exception('Something wrong with the file')

        result = np.frombuffer(data, dtype=np.uint8).reshape(
            len(bytes_)//n_bytes_per_img, n_bytes_per_img)

    return result

def decode_label_file(fname):
    result = []

    with gzip.open(fname, 'rb') as f:
        bytes_ = f.read()
        data = bytes_[8:]

        result = np.frombuffer(data, dtype=np.uint8)

    return result

train_images = decode_image_file('train-images-idx3-ubyte.gz')
train_labels = decode_label_file('train-labels-idx1-ubyte.gz')

test_images = decode_image_file('t10k-images-idx3-ubyte.gz')
test_labels = decode_label_file('t10k-labels-idx1-ubyte.gz')

The script doesn't normalize the pixel values like in the pickled file. To do that, all you have to do is

train_images = train_images/255
test_images = test_images/255

How to fix the error "Windows SDK version 8.1" was not found?

I faced this problem too. Re-ran the Visual Studio 2017 Installer, go to 'Individual Components' and select Windows 8.1 SDK. Go back to to the project > Right click and Re-target to match the SDK required as shown below:enter image description here

What is your favorite C programming trick?

I love empty if-else and while(0) operators.

For example:

#define CMD1(X) do { foo(x); bar(x); } while (0)
#define CMD2(X) if (1) { foo(x); bar(x); } else

Programmatically Check an Item in Checkboxlist where text is equal to what I want

//Multiple selection:

          private void clbsec(CheckedListBox clb, string text)
          {
              for (int i = 0; i < clb.Items.Count; i++)
              {
                  if(text == clb.Items[i].ToString())
                  {
                      clb.SetItemChecked(i, true);
                  }
              }
          }

using ==>

clbsec(checkedListBox1,"michael");

or 

clbsec(checkedListBox1,textBox1.Text);

or

clbsec(checkedListBox1,dataGridView1.CurrentCell.Value.toString());

Scroll to bottom of div with Vue.js

I tried the accepted solution and it didn't work for me. I use the browser debugger and found out the actual height that should be used is the clientHeight BUT you have to put this into the updated() hook for the whole solution to work.

data(){
return {
  conversation: [
    {
    }
  ]
 },
mounted(){
 EventBus.$on('msg-ctr--push-msg-in-conversation', textMsg => {
  this.conversation.push(textMsg)
  // Didn't work doing scroll here
 })
},
updated(){              <=== PUT IT HERE !!
  var elem = this.$el
  elem.scrollTop = elem.clientHeight;
},

Moving Average Pandas

The rolling mean returns a Series you only have to add it as a new column of your DataFrame (MA) as described below.

For information, the rolling_mean function has been deprecated in pandas newer versions. I have used the new method in my example, see below a quote from the pandas documentation.

Warning Prior to version 0.18.0, pd.rolling_*, pd.expanding_*, and pd.ewm* were module level functions and are now deprecated. These are replaced by using the Rolling, Expanding and EWM. objects and a corresponding method call.

df['MA'] = df.rolling(window=5).mean()

print(df)
#             Value    MA
# Date                   
# 1989-01-02   6.11   NaN
# 1989-01-03   6.08   NaN
# 1989-01-04   6.11   NaN
# 1989-01-05   6.15   NaN
# 1989-01-09   6.25  6.14
# 1989-01-10   6.24  6.17
# 1989-01-11   6.26  6.20
# 1989-01-12   6.23  6.23
# 1989-01-13   6.28  6.25
# 1989-01-16   6.31  6.27

How to return only the Date from a SQL Server DateTime datatype

My common approach to get date without the time part..

 SELECT CONVERT(VARCHAR(MAX),GETDATE(),103)

 SELECT CAST(GETDATE() AS DATE)

Entity Framework: table without primary key

THIS SOLUTION WORKS

You do not need to map manually even if you dont have a PK. You just need to tell the EF that one of your columns is index and index column is not nullable.

To do this you can add a row number to your view with isNull function like the following

select 
    ISNULL(ROW_NUMBER() OVER (ORDER BY xxx), - 9999) AS id
from a

ISNULL(id, number) is the key point here because it tells the EF that this column can be primary key

Setting the zoom level for a MKMapView

It's not built in, but I've seen / used this code. This allows you to use this:

[mapView setCenterCoordinate:myCoord zoomLevel:13 animated:YES];

Note: This is not my code, I did not write it, so therefore can't take credit for it

Run a task every x-minutes with Windows Task Scheduler

The task must be configured in two steps.

First you create a simple task that start at 0:00, every day. Then, you go in Advanced... (or similar depending on the operating system you are on) and select the Repeat every X minutes option for 24 hours.

The key here is to find the advanced properties. If you are using the XP wizard, it will only offer you to launch the advanced dialog once you created the task.

On more recent versions of Windows (7+ I think?):

  1. Double click the task and a property window will show up.
  2. Click the Triggers tab.
  3. Double click the trigger details and the Edit Trigger window will show up.
  4. Under Advanced settings panel, tick Repeat task every xxx minutes, and set Indefinitely if you need.
  5. Finally, click ok.

lodash multi-column sortBy descending

It's worth noting that if you want to sort particular properties descending, you don't want to simply append .reverse() at the end, as this will make all of the sorts descending.

To make particular sorts descending, chain your sorts from least significant to most significant, calling .reverse() after each sort that you want to be descending.

var data = _(data).chain()
    .sort("date")
    .reverse()    // sort by date descending
    .sort("name") // sort by name ascending
    .result()

Since _'s sort is a stable sort, you can safely chain and reverse sorts because if two items have the same value for a property, their order is preserved.

More information

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

You need to declare the type of the protocol as AnyObject.

protocol ProtocolNameDelegate: AnyObject {
    // Protocol stuff goes here
}

class SomeClass {
    weak var delegate: ProtocolNameDelegate?
}

Using AnyObject you say that only classes can conform to this protocol, whereas structs or enums can't.

how to change a selections options based on another select option selected?

I don't quote understand what you are trying to achieve, but you need an event listener. Something like:

$('#type').change(function() {
   alert('Value changed to ' + $(this).attr('value'));
});

This will give you the value of the selected option tag.

git with development, staging and production branches

one of the best things about git is that you can change the work flow that works best for you.. I do use http://nvie.com/posts/a-successful-git-branching-model/ most of the time but you can use any workflow that fits your needs

How to add image for button in android?

As he stated, used the ImageButton widget. Copy your image file within the Res/drawable/ directory of your project. While in XML simply go into the graphic representation (for simplicity) of your XML file and click on your ImageButton widget that you added, go to its properties sheet and click on the [...] in the src: field. Simply navigate to your image file. Also, make sure you're using a proper format; I tend to stick with .png files for my own reasons, but they work.

PHP Array to CSV

Instead of writing out values consider using fputcsv().

This may solve your problem immediately.

Binding ng-model inside ng-repeat loop in AngularJS

<h4>Order List</h4>
<ul>
    <li ng-repeat="val in filter_option.order">
        <span>
            <input title="{{filter_option.order_name[$index]}}" type="radio" ng-model="filter_param.order_option" ng-value="'{{val}}'" />
            &nbsp;{{filter_option.order_name[$index]}}
        </span>
        <select title="" ng-model="filter_param[val]">
            <option value="asc">Asc</option>
            <option value="desc">Desc</option>
        </select>
    </li>
</ul>

What is the JUnit XML format specification that Hudson supports?

Good answers here on using python: (there are many ways to do it) Python unittests in Jenkins?

IMHO the best way is write python unittest tests and install pytest (something like 'yum install pytest') to get py.test installed. Then run tests like this: 'py.test --junitxml results.xml test.py'. You can run any unittest python script and get jUnit xml results.

https://docs.python.org/2.7/library/unittest.html

In jenkins build configuration Post-build actions Add a "Publish JUnit test result report" action with result.xml and any more test result files you produce.

How to automatically allow blocked content in IE?

That's something I'm not sure that you can change through the HTML of the webpage itself, it's a client-side setting to tell their browser if they want security to be high. Most other browsers will not do this but from what I'm aware of this is not possible to stop unless the user disables the feature.

Does it still do what you want it to do after you click on 'Allow'? If so then it shouldn't be too much of a problem

How can I display the current branch and folder path in terminal?

From Mac OS Catalina .bash_profile is replaced with .zprofile

Step 1: Create a .zprofile

touch .zprofile

Step 2:

nano .zprofile

type below line in this

source ~/.bash_profile

and save(ctrl+o return ctrl+x)

Step 3: Restart your terminal

To Add Git Branch Name Now you can add below lines in .bash_profile

    parse_git_branch() {
    git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ (\1)/'
}

export PS1="\u@\h \[\033[32m\]\w - \$(parse_git_branch)\[\033[00m\] $ "

Restart your terminal this will work.

Note: Even you can rename .bash_profile to .zprofile that also works.

jQuery Set Cursor Position in Text Area

I have two functions:

function setSelectionRange(input, selectionStart, selectionEnd) {
  if (input.setSelectionRange) {
    input.focus();
    input.setSelectionRange(selectionStart, selectionEnd);
  }
  else if (input.createTextRange) {
    var range = input.createTextRange();
    range.collapse(true);
    range.moveEnd('character', selectionEnd);
    range.moveStart('character', selectionStart);
    range.select();
  }
}

function setCaretToPos (input, pos) {
  setSelectionRange(input, pos, pos);
}

Then you can use setCaretToPos like this:

setCaretToPos(document.getElementById("YOURINPUT"), 4);

Live example with both a textarea and an input, showing use from jQuery:

_x000D_
_x000D_
function setSelectionRange(input, selectionStart, selectionEnd) {_x000D_
  if (input.setSelectionRange) {_x000D_
    input.focus();_x000D_
    input.setSelectionRange(selectionStart, selectionEnd);_x000D_
  } else if (input.createTextRange) {_x000D_
    var range = input.createTextRange();_x000D_
    range.collapse(true);_x000D_
    range.moveEnd('character', selectionEnd);_x000D_
    range.moveStart('character', selectionStart);_x000D_
    range.select();_x000D_
  }_x000D_
}_x000D_
_x000D_
function setCaretToPos(input, pos) {_x000D_
  setSelectionRange(input, pos, pos);_x000D_
}_x000D_
_x000D_
$("#set-textarea").click(function() {_x000D_
  setCaretToPos($("#the-textarea")[0], 10)_x000D_
});_x000D_
$("#set-input").click(function() {_x000D_
  setCaretToPos($("#the-input")[0], 10);_x000D_
});
_x000D_
<textarea id="the-textarea" cols="40" rows="4">Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</textarea>_x000D_
<br><input type="button" id="set-textarea" value="Set in textarea">_x000D_
<br><input id="the-input" type="text" size="40" value="Lorem ipsum dolor sit amet, consectetur adipiscing elit">_x000D_
<br><input type="button" id="set-input" value="Set in input">_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
_x000D_
_x000D_
_x000D_

As of 2016, tested and working on Chrome, Firefox, IE11, even IE8 (see that last here; Stack Snippets don't support IE8).

When to use 'npm start' and when to use 'ng serve'?

From the document

npm-start :

This runs an arbitrary command specified in the package's "start" property of its "scripts" object. If no "start" property is specified on the "scripts" object, it will run node server.js.

which means it will call the start scripts inside the package.json

"scripts": {
"start": "tsc && concurrently \"npm run tsc:w\" \"npm run lite --baseDir ./app --port 8001\" ",
"lite": "lite-server",
 ...
}

ng serve:

Provided by angular/angular-cli to start angular2 apps which created by angular-cli. when you install angular-cli, it will create ng.cmd under C:\Users\name\AppData\Roaming\npm (for windows) and execute "%~dp0\node.exe" "%~dp0\node_modules\angular-cli\bin\ng" %*

So using npm start you can make your own execution where is ng serve is only for angular-cli

See Also : What happens when you run ng serve?

Mocking HttpClient in unit tests

This is an old question, but I feel the urge to extend the answers with a solution I didn't see here.
You can fake the Microsoft assemly (System.Net.Http) and then use ShinsContext during the test.

  1. In VS 2017, right click on the System.Net.Http assembly and choose "Add Fakes Assembly"
  2. Put your code in the unit test method under a ShimsContext.Create() using. This way, you can isolate the code where you are planning to fake the HttpClient.
  3. Depends on your implementation and test, I would suggest to implement all the desired acting where you call a method on the HttpClient and want to fake the returned value. Using ShimHttpClient.AllInstances will fake your implementation in all the instances created during your test. For example, if you want to fake the GetAsync() method, do the following:

    [TestMethod]
    public void FakeHttpClient()
    {
        using (ShimsContext.Create())
        {
            System.Net.Http.Fakes.ShimHttpClient.AllInstances.GetAsyncString = (c, requestUri) =>
            {
              //Return a service unavailable response
              var httpResponseMessage = new HttpResponseMessage(HttpStatusCode.ServiceUnavailable);
              var task = Task.FromResult(httpResponseMessage);
              return task;
            };
    
            //your implementation will use the fake method(s) automatically
            var client = new Connection(_httpClient);
            client.doSomething(); 
        }
    }
    

How to change the plot line color from blue to black?

The usual way to set the line color in matplotlib is to specify it in the plot command. This can either be done by a string after the data, e.g. "r-" for a red line, or by explicitely stating the color argument.

import matplotlib.pyplot as plt

plt.plot([1,2,3], [2,3,1], "r-") # red line
plt.plot([1,2,3], [5,5,3], color="blue") # blue line

plt.show()

See also the plot command's documentation.

In case you already have a line with a certain color, you can change that with the lines2D.set_color() method.

line, = plt.plot([1,2,3], [4,5,3], color="blue")
line.set_color("black")


Setting the color of a line in a pandas plot is also best done at the point of creating the plot:

import matplotlib.pyplot as plt
import pandas as pd

df = pd.DataFrame({ "x" : [1,2,3,5], "y" : [3,5,2,6]})
df.plot("x", "y", color="r") #plot red line

plt.show()

If you want to change this color later on, you can do so by

plt.gca().get_lines()[0].set_color("black")

This will get you the first (possibly the only) line of the current active axes.
In case you have more axes in the plot, you could loop through them

for ax in plt.gcf().axes:
    ax.get_lines()[0].set_color("black")

and if you have more lines you can loop over them as well.

Order by multiple columns with Doctrine

The comment for orderBy source code notes: Keys are field and values are the order, being either ASC or DESC.. So you can do orderBy->(['field' => Criteria::ASC]).

JavaScript hashmap equivalent

JavaScript does not have a built-in map/hashmap. It should be called an associative array.

hash["X"] is equal to hash.X, but it allows "X" as a string variable. In other words, hash[x] is functionally equal to eval("hash."+x.toString()).

It is more similar to object.properties rather than key-value mapping. If you are looking for a better key/value mapping in JavaScript, please use the Map object.

How to split a string between letters and digits (or between digits and letters)?

How about:

private List<String> Parse(String str) {
    List<String> output = new ArrayList<String>();
    Matcher match = Pattern.compile("[0-9]+|[a-z]+|[A-Z]+").matcher(str);
    while (match.find()) {
        output.add(match.group());
    }
    return output;
}

Jquery Date picker Default Date

Use the defaultDate option

$( ".selector" ).datepicker({ defaultDate: '01/01/01' });

If you change your date format, make sure to change the input into defaultDate (e.g. '01-01-2001')

Preloading @font-face fonts?

This answer is no longer up to date

Please refer to this updated answer: https://stackoverflow.com/a/46830425/4031815


Deprecated answer

I'm not aware of any current technique to avoid the flicker as the font loads, however you can minimize it by sending proper cache headers for your font and making sure that that request goes through as quickly as possible.

Create html documentation for C# code

This page might interest you: http://msdn.microsoft.com/en-us/magazine/dd722812.aspx

You can generate the XML documentation file using either the command-line compiler or through the Visual Studio interface. If you are compiling with the command-line compiler, use options /doc or /doc+. That will generate an XML file by the same name and in the same path as the assembly. To specify a different file name, use /doc:file.

If you are using the Visual Studio interface, there's a setting that controls whether the XML documentation file is generated. To set it, double-click My Project in Solution Explorer to open the Project Designer. Navigate to the Compile tab. Find "Generate XML documentation file" at the bottom of the window, and make sure it is checked. By default this setting is on. It generates an XML file using the same name and path as the assembly.

Why do Sublime Text 3 Themes not affect the sidebar?

I had the same problem. Just set the theme in Preferences -> Settings – User by editing the json property called.

{
    // Default theme
    "theme": "Material-Theme.sublime-theme",
    "color_scheme": "Packages/Material Theme/schemes/Material-Theme.tmTheme"
}

For Material theme that I use. It worked for me.

What is .Net Framework 4 extended?

It's the part of the .NET Framework that isn't contained within the Client Profile. See MSDN for more info; specifically:

The .NET Framework is made up of the .NET Framework 4 Client Profile and .NET Framework 4 Extended components that exist separately in Programs and Features.

C# elegant way to check if a property's property is null

I would write your own method in the type of PropertyA (or an extension method if it's not your type) using the similar pattern to the Nullable type.

class PropertyAType
{
   public PropertyBType PropertyB {get; set; }

   public PropertyBType GetPropertyBOrDefault()
   {
       return PropertyB != null ? PropertyB : defaultValue;
   }
}

Initializing array of structures

This is quite simple: my_data is a before defined structure type. So you want to declare an my_data-array of some elements, as you would do with

char a[] = { 'a', 'b', 'c', 'd' };

So the array would have 4 elements and you initialise them as

a[0] = 'a', a[1] = 'b', a[1] = 'c', a[1] ='d';

This is called a designated initializer (as i remember right).

and it just indicates that data has to be of type my_dat and has to be an array that needs to store so many my_data structures that there is a structure with each type member name Peter, James, John and Mike.

Adding one day to a date

The following code get the first day of January of current year (but it can be a another date) and add 365 days to that day (but it can be N number of days) using DateTime class and its method modify() and format():

echo (new DateTime((new DateTime())->modify('first day of January this year')->format('Y-m-d')))->modify('+365 days')->format('Y-m-d');

Capture characters from standard input without waiting for enter to be pressed

CONIO.H

the functions you need are:

int getch();
Prototype
    int _getch(void); 
Description
    _getch obtains a character  from stdin. Input is unbuffered, and this
    routine  will  return as  soon as  a character is  available  without 
    waiting for a carriage return. The character is not echoed to stdout.
    _getch bypasses the normal buffering done by getchar and getc. ungetc 
    cannot be used with _getch. 
Synonym
    Function: getch 


int kbhit();
Description
    Checks if a keyboard key has been pressed but not yet read. 
Return Value
    Returns a non-zero value if a key was pressed. Otherwise, returns 0.

libconio http://sourceforge.net/projects/libconio

or

Linux c++ implementation of conio.h http://sourceforge.net/projects/linux-conioh

Finding the Eclipse Version Number

Here is a working code snippet that will print out the full version of currently running Eclipse (or any RCP-based application).

String product = System.getProperty("eclipse.product");
IExtensionRegistry registry = Platform.getExtensionRegistry();
IExtensionPoint point = registry.getExtensionPoint("org.eclipse.core.runtime.products");
Logger log = LoggerFactory.getLogger(getClass());
if (point != null) {
  IExtension[] extensions = point.getExtensions();
  for (IExtension ext : extensions) {
    if (product.equals(ext.getUniqueIdentifier())) {
      IContributor contributor = ext.getContributor();
      if (contributor != null) {
        Bundle bundle = Platform.getBundle(contributor.getName());
        if (bundle != null) {
          System.out.println("bundle version: " + bundle.getVersion());
        }
      }
    }
  }
}

It looks up the currently running "product" extension and takes the version of contributing plugin.

On Eclipse Luna 4.4.0, it gives the result of 4.4.0.20140612-0500 which is correct.

PANIC: Broken AVD system path. Check your ANDROID_SDK_ROOT value

Similar issues on macOS Catalina and the issue turned out to be the version of Java that I was running. By default, when Java is installed now, it's version 13, which does not work with the current version of avd.

Additionally, I had trouble installing Java 8, so I used the one that's available in Homebrew:

brew cask install homebrew/cask-versions/adoptopenjdk8

Then, in my ~/.profile I set the Java version to 1.8:

export JAVA_HOME=$(/usr/libexec/java_home -v 1.8)

Now it's possible to test if the avdmanager can run and detect the virtual devices (previously, this resulted in an error saying the XML cannot be parsed):

avdmanager list avds

How to change JFrame icon

Just add the following code:

setIconImage(new ImageIcon(PathOfFile).getImage());

Converting file size in bytes to human-readable string

My answer might be late, but I guess it will help someone.

Metric prefix:

/**
 * Format file size in metric prefix
 * @param fileSize
 * @returns {string}
 */
const formatFileSizeMetric = (fileSize) => {
  let size = Math.abs(fileSize);

  if (Number.isNaN(size)) {
    return 'Invalid file size';
  }

  if (size === 0) {
    return '0 bytes';
  }

  const units = ['bytes', 'kB', 'MB', 'GB', 'TB'];
  let quotient = Math.floor(Math.log10(size) / 3);
  quotient = quotient < units.length ? quotient : units.length - 1;
  size /= (1000 ** quotient);

  return `${+size.toFixed(2)} ${units[quotient]}`;
};

Binary prefix:

/**
 * Format file size in binary prefix
 * @param fileSize
 * @returns {string}
 */
const formatFileSizeBinary = (fileSize) => {
  let size = Math.abs(fileSize);

  if (Number.isNaN(size)) {
    return 'Invalid file size';
  }

  if (size === 0) {
    return '0 bytes';
  }

  const units = ['bytes', 'kiB', 'MiB', 'GiB', 'TiB'];
  let quotient = Math.floor(Math.log2(size) / 10);
  quotient = quotient < units.length ? quotient : units.length - 1;
  size /= (1024 ** quotient);

  return `${+size.toFixed(2)} ${units[quotient]}`;
};

Examples:

// Metrics prefix
formatFileSizeMetric(0)      // 0 bytes
formatFileSizeMetric(-1)     // 1 bytes
formatFileSizeMetric(100)    // 100 bytes
formatFileSizeMetric(1000)   // 1 kB
formatFileSizeMetric(10**5)  // 10 kB
formatFileSizeMetric(10**6)  // 1 MB
formatFileSizeMetric(10**9)  // 1GB
formatFileSizeMetric(10**12) // 1 TB
formatFileSizeMetric(10**15) // 1000 TB

// Binary prefix
formatFileSizeBinary(0)     // 0 bytes
formatFileSizeBinary(-1)    // 1 bytes
formatFileSizeBinary(1024)  // 1 kiB
formatFileSizeBinary(2048)  // 2 kiB
formatFileSizeBinary(2**20) // 1 MiB
formatFileSizeBinary(2**30) // 1 GiB
formatFileSizeBinary(2**40) // 1 TiB
formatFileSizeBinary(2**50) // 1024 TiB

How can you program if you're blind?

What in the world would a braille keyboard even be??

There are such things as braille writers but you would never use one as an input device for a computer.

If you're simply talking about a keyboard with the braille symbols on it this would also be a very bad idea. You're going to have a lot more keys to reach while typing and it would still be slower.

Touch typing is NOT a visual skill, a blind person can do it just as well as a sighted person.

How to replace text in a column of a Pandas dataframe?

In addition, for those looking to replace more than one character in a column, you can do it using regular expressions:

import re
chars_to_remove = ['.', '-', '(', ')', '']
regular_expression = '[' + re.escape (''. join (chars_to_remove)) + ']'

df['string_col'].str.replace(regular_expression, '', regex=True)

Running .sh scripts in Git Bash

Let's say you have a script script.sh. To run it (using Git Bash), you do the following: [a] Add a "sh-bang" line on the first line (e.g. #!/bin/bash) and then [b]:

# Use ./ (or any valid dir spec):
./script.sh

Note: chmod +x does nothing to a script's executability on Git Bash. It won't hurt to run it, but it won't accomplish anything either.

How do I load an org.w3c.dom.Document from XML in a string?

Just had a similar problem, except i needed a NodeList and not a Document, here's what I came up with. It's mostly the same solution as before, augmented to get the root element down as a NodeList and using erickson's suggestion of using an InputSource instead for character encoding issues.

private String DOC_ROOT="root";
String xml=getXmlString();
Document xmlDoc=loadXMLFrom(xml);
Element template=xmlDoc.getDocumentElement();
NodeList nodes=xmlDoc.getElementsByTagName(DOC_ROOT);

public static Document loadXMLFrom(String xml) throws Exception {
        InputSource is= new InputSource(new StringReader(xml));
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        factory.setNamespaceAware(true);
        DocumentBuilder builder = null;
        builder = factory.newDocumentBuilder();
        Document doc = builder.parse(is);
        return doc;
    }

How to increase font size in NeatBeans IDE?

Tools -> Options -> Fonts & Colors -> then click on Font browse option. Now you will see a popup box. Here you can change Font:, Font Style: and Size:

I had tested it.

How to compare oldValues and newValues on React Hooks useEffect?

If you prefer a useEffect replacement approach:

const usePreviousEffect = (fn, inputs = []) => {
  const previousInputsRef = useRef([...inputs])

  useEffect(() => {
    fn(previousInputsRef.current)
    previousInputsRef.current = [...inputs]
  }, inputs)
}

And use it like this:

usePreviousEffect(
  ([prevReceiveAmount, prevSendAmount]) => {
    if (prevReceiveAmount !== receiveAmount) // side effect here
    if (prevSendAmount !== sendAmount) // side effect here
  },
  [receiveAmount, sendAmount]
)

Note that the first time the effect executes, the previous values passed to your fn will be the same as your initial input values. This would only matter to you if you wanted to do something when a value did not change.

Any easy way to use icons from resources?

Forms maintain separate resource files (SomeForm.Designer.resx) added via the designer. To use icons embedded in another resource file requires codes. (this.Icone = Project.Resources.SomeIcon;)

Creating an empty list in Python

I do not really know about it, but it seems to me, by experience, that jpcgt is actually right. Following example: If I use following code

t = [] # implicit instantiation
t = t.append(1)

in the interpreter, then calling t gives me just "t" without any list, and if I append something else, e.g.

t = t.append(2)

I get the error "'NoneType' object has no attribute 'append'". If, however, I create the list by

t = list() # explicit instantiation

then it works fine.

How do I set combobox read-only or user cannot write in a combo box only can select the given items?

Make the DropDownStyle to DropDownList

stateComboBox.DropDownStyle = ComboBoxStyle.DropDownList;

Taskkill /f doesn't kill a process

I had the same problem and as many others here have said none of the normal Kill commands worked. My problem file was an executable that was being run from a network share by a user on a Remote Desktop Server. With multiple shared users not an easy thing to restart in during a work day. Even when the user logged off the exe was still listed in Task Manager. I sent to the server where the folder was shared and from Computer Management -> Sessions found the user with the session still open from that RDP server even though he was logged off. Right Click -> Close Session and the file lock was released.

Beats me why I couldn't end the taks. The error message I was originally getting when I try and delete the file was "The action can't be completed because the file is open in System"

Hope this helps someone else.

How can I catch all the exceptions that will be thrown through reading and writing a file?

It is bad practice to catch Exception -- it's just too broad, and you may miss something like a NullPointerException in your own code.

For most file operations, IOException is the root exception. Better to catch that, instead.

Convert string to number field

Within Crystal, you can do it by creating a formula that uses the ToNumber function. It might be a good idea to code for the possibility that the field might include non-numeric data - like so:

If NumericText ({field}) then ToNumber ({field}) else 0

Alternatively, you might find it easier to convert the field's datatype within the query used in the report.

Characters allowed in a URL

EDIT: As @Jukka K. Korpela correctly points out, RFC 1738 was updated by RFC 3986. This has expanded and clarified the characters valid for host, unfortunately it's not easily copied and pasted, but I'll do my best.

In first matched order:

host        = IP-literal / IPv4address / reg-name

IP-literal  = "[" ( IPv6address / IPvFuture  ) "]"

IPvFuture   = "v" 1*HEXDIG "." 1*( unreserved / sub-delims / ":" )

IPv6address =         6( h16 ":" ) ls32
                  /                       "::" 5( h16 ":" ) ls32
                  / [               h16 ] "::" 4( h16 ":" ) ls32
                  / [ *1( h16 ":" ) h16 ] "::" 3( h16 ":" ) ls32
                  / [ *2( h16 ":" ) h16 ] "::" 2( h16 ":" ) ls32
                  / [ *3( h16 ":" ) h16 ] "::"    h16 ":"   ls32
                  / [ *4( h16 ":" ) h16 ] "::"              ls32
                  / [ *5( h16 ":" ) h16 ] "::"              h16
                  / [ *6( h16 ":" ) h16 ] "::"

ls32        = ( h16 ":" h16 ) / IPv4address
                  ; least-significant 32 bits of address

h16         = 1*4HEXDIG 
               ; 16 bits of address represented in hexadecimal

IPv4address = dec-octet "." dec-octet "." dec-octet "." dec-octet

dec-octet   = DIGIT                 ; 0-9
              / %x31-39 DIGIT         ; 10-99
              / "1" 2DIGIT            ; 100-199
              / "2" %x30-34 DIGIT     ; 200-249
              / "25" %x30-35          ; 250-255

reg-name    = *( unreserved / pct-encoded / sub-delims )

unreserved  = ALPHA / DIGIT / "-" / "." / "_" / "~"     <---This seems like a practical shortcut, most closely resembling original answer

reserved    = gen-delims / sub-delims

gen-delims  = ":" / "/" / "?" / "#" / "[" / "]" / "@"

sub-delims  = "!" / "$" / "&" / "'" / "(" / ")"
              / "*" / "+" / "," / ";" / "="

pct-encoded = "%" HEXDIG HEXDIG

Original answer from RFC 1738 specification:

Thus, only alphanumerics, the special characters "$-_.+!*'(),", and reserved characters used for their reserved purposes may be used unencoded within a URL.

^ obsolete since 1998.

Localhost : 404 not found

You need to add the port number to every address you type in your browser when you have changed the default port from port 80.

For example: localhost:8000/cc .

A little edition here is that it should be 8080 in place of 8000. For example - http://localhost:8080/phpmyadmin/

SQL Server Text type vs. varchar data type

In SQL server 2005 new datatypes were introduced: varchar(max) and nvarchar(max) They have the advantages of the old text type: they can contain op to 2GB of data, but they also have most of the advantages of varchar and nvarchar. Among these advantages are the ability to use string manipulation functions such as substring().

Also, varchar(max) is stored in the table's (disk/memory) space while the size is below 8Kb. Only when you place more data in the field, it's is stored out of the table's space. Data stored in the table's space is (usually) retrieved quicker.

In short, never use Text, as there is a better alternative: (n)varchar(max). And only use varchar(max) when a regular varchar is not big enough, ie if you expect teh string that you're going to store will exceed 8000 characters.

As was noted, you can use SUBSTRING on the TEXT datatype,but only as long the TEXT fields contains less than 8000 characters.

Can't escape the backslash with regex?

If you're putting this in a string within a program, you may actually need to use four backslashes (because the string parser will remove two of them when "de-escaping" it for the string, and then the regex needs two for an escaped regex backslash).

For instance:

regex("\\\\")

is interpreted as...

regex("\\" [escaped backslash] followed by "\\" [escaped backslash])

is interpreted as...

regex(\\)

is interpreted as a regex that matches a single backslash.


Depending on the language, you might be able to use a different form of quoting that doesn't parse escape sequences to avoid having to use as many - for instance, in Python:

re.compile(r'\\')

The r in front of the quotes makes it a raw string which doesn't parse backslash escapes.

How to check if a socket is connected/disconnected in C#?

Just use the KeepAlive like @toster-cx says and then use the Socket Connected status to check if the Socket is still connected. Set your receive timeout at the same timeout of the keepalive. If you have more questions i am always happy to help!

How to generate and validate a software license key?

It is not possible to prevent software piracy completely. You can prevent casual piracy and that's what all licensing solutions out their do.

Node (machine) locked licensing is best if you want to prevent reuse of license keys. I have been using Cryptlex for about a year now for my software. It has a free plan also, so if you don't expect too many customers you can use it for free.

Javascript one line If...else...else if statement

Sure, you can do nested ternary operators but they are hard to read.

var variable = (condition) ? (true block) : ((condition2) ? (true block2) : (else block2))

Iterating over ResultSet and adding its value in an ArrayList

If I've understood your problem correctly, there are two possible problems here:

  • resultset is null - I assume that this can't be the case as if it was you'd get an exception in your while loop and nothing would be output.
  • The second problem is that resultset.getString(i++) will get columns 1,2,3 and so on from each subsequent row.

I think that the second point is probably your problem here.

Lets say you only had 1 row returned, as follows:

Col 1, Col 2, Col 3 
A    ,     B,     C

Your code as it stands would only get A - it wouldn't get the rest of the columns.

I suggest you change your code as follows:

ResultSet resultset = ...;
ArrayList<String> arrayList = new ArrayList<String>(); 
while (resultset.next()) {                      
    int i = 1;
    while(i <= numberOfColumns) {
        arrayList.add(resultset.getString(i++));
    }
    System.out.println(resultset.getString("Col 1"));
    System.out.println(resultset.getString("Col 2"));
    System.out.println(resultset.getString("Col 3"));                    
    System.out.println(resultset.getString("Col n"));
}

Edit:

To get the number of columns:

ResultSetMetaData metadata = resultset.getMetaData();
int numberOfColumns = metadata.getColumnCount();

How can I get session id in php and show it?

session_start();    
echo session_id();

Linux c++ error: undefined reference to 'dlopen'

I was using CMake to compile my project and I've found the same problem.

The solution described here works like a charm, simply add ${CMAKE_DL_LIBS} to the target_link_libraries() call

Getting started with OpenCV 2.4 and MinGW on Windows 7

This isn't working for me. I spent few days following every single tutorial I found on net and finally i compiled my own binaries. Everyting is described here: OpenVC 2.4.5, eclipse CDT Juno, MinGW error 0xc0000005

After many trials and errors I decided to follow this tutorial and to compile my own binaries as it seems that too many people are complaining that precompiled binaries are NOT working for them. Eclipse CDT Juno was already installed.

My procedure was as follows:

  1. Download and install MinGW and add to the system PATH with c:/mingw/bin
  2. Download cmake from http://www.cmake.org and install it
  3. Download OpenCV2.4.5 Windows version
  4. Install/unzip Opencv to C:\OpenCV245PC\ (README,index.rst and CMakeLists.txt are there with all subfolders)
  5. Run CMake GUI tool, then
  6. Choose C:\OpenCV245PC\ as source
  7. Choose the destination, C:\OpenCV245MinGW\x86 where to build the binaries
  8. Press Configure button, choose MinGW Makefiles as the generator. There are some red highlights in the window, choose options as you need.
  9. Press the Configure button again. Configuring is now done.
  10. Press the Generate button.
  11. Exit the program when the generating is done.
  12. Exit the Cmake program.
  13. Run the command line mode (cmd.exe) and go to the destination directory C:\OpenCV245MinGW\x86
  14. Type "mingw32-make". You will see a progress of building binaries. If the command is not found, you must make sure that the system PATH is added with c:/mingw/bin. The build continues according the chosen options to a completion.
  15. In Windows system PATH (My Computer > Right button click > Properties > Advanced > Environment Variables > Path) add the destination's bin directory, C:\OpenCV245MinGW\x86\bin
  16. RESTART COMPUTER
  17. Go to the Eclipse CDT IDE, create a C++ program using the sample OpenCV code (You can use code from top of this topic).
  18. Go to Project > Properties > C/C++ Build > Settings > GCC C++ Compiler > Includes, and add the source OpenCV folder "C:\OpenCV245PC\build\include"
  19. Go to Project > Properties > C/C++ Build > Settings > MinGW C++ Linker > Libraries, and add to the Libraries (-l) ONE BY ONE (this could vary from project to project, you can add all of them if you like or some of them just the ones that you need for your project): opencv_calib3d245 opencv_contrib245 opencv_core245 opencv_features2d245 opencv_flann245 opencv_gpu245 opencv_highgui245 opencv_imgproc245 opencv_legacy245 opencv_ml245 opencv_nonfree245 opencv_objdetect245 opencv_photo245 opencv_stitching245 opencv_video245 opencv_videostab245
  20. Add the built OpenCV library folder, "C:\OpenCV245MinGW\x86\lib" to Library search path (-L).

You can use this code to test your setup:

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/opencv.hpp>
#include <iostream>

using namespace std;
using namespace cv;

int main()
{

Mat img = imread("c:/lenna.png", CV_LOAD_IMAGE_COLOR);

namedWindow("MyWindow", CV_WINDOW_AUTOSIZE);
imshow("MyWindow", img);

waitKey(0);
return 0;
}

Don't forget to put image to the C:/ (or wherever you might find suitable, just be sure that eclipse have read acess.

Is it ok to use `any?` to check if an array is not empty?

any? isn't the same as not empty? in some cases.

>> [nil, 1].any?
=> true
>> [nil, nil].any?
=> false

From the documentation:

If the block is not given, Ruby adds an implicit block of {|obj| obj} (that is any? will return true if at least one of the collection members is not false or nil).

How to build & install GLFW 3 and use it in a Linux project

Since the accepted answer does not allow more edits, I'm going to summarize it with a single copy-paste command (Replace 3.2.1 with the latest version available in the first line):

version="3.2.1" && \
wget "https://github.com/glfw/glfw/releases/download/${version}/glfw-${version}.zip" && \
unzip glfw-${version}.zip && \
cd glfw-${version} && \
sudo apt-get install cmake xorg-dev libglu1-mesa-dev && \
sudo cmake -G "Unix Makefiles" && \
sudo make && \
sudo make install

If you want to compile a program use the following commands:

g++ -std=c++11 -c main.cpp && \
g++ main.o -o main.exec -lGL -lGLU -lglfw3 -lX11 -lXxf86vm -lXrandr -lpthread -lXi -ldl -lXinerama -lXcursor

If you are following the learnopengl.com tutorial you may have to set up GLAD as well. In such case click on this link

http://glad.dav1d.de/#profile=core&specification=gl&api=gl%3D3.3&api=gles1%3Dnone&api=gles2%3Dnone&api=glsc2%3Dnone&language=c&loader=on

and then click on the "Generate" button at the bottom right corner of the website and download the zip file. Extract it and compile the sources with the following command:

g++ glad/src/glad.c -c -Iglad/include

Now, the commands to compile your program become like this:

g++ -std=c++11 -c main.cpp -Iglad/include && \
g++ main.o glad.o -o main.exec -lGL -lGLU -lglfw3 -lX11 -lXxf86vm -lXrandr -lpthread -lXi -ldl -lXinerama -lXcursor

Windows command for file size only

In a batch file, the below works for local files, but fails for files on network hard drives

for %%I in ("test.jpg") do @set filesize=%~z1

However, it's inferior code, because it doesn't work for files saved on a network drive (for example, \\Nas\test.jpg and \\192.168.2.40\test.jpg). The below code works for files in any location, and I wrote it myself.

I'm sure there are more efficient ways of doing this using VBScript, or PowerShell or whatever, but I didn't want to do any of that; good ol' batch for me!

set file=C:\Users\Admin\Documents\test.jpg
set /a filesize=
set fileExclPath=%file:*\=%

:onemoretime
set fileExclPath2=%fileExclPath:*\=%
set fileExclPath=%fileExclPath2:*\=%
if /i "%fileExclPath%" NEQ "%fileExclPath2%" goto:onemoretime

dir /s /a-d "%workingdir%">"%temp%\temp.txt"
findstr /C:"%fileExclPath%" "%temp%\temp.txt" >"%temp%\temp2.txt"

set /p filesize= <"%temp%\temp2.txt"

echo set filesize=%%filesize: %fileExclPath%%ext%=%% >"%temp%\temp.bat"
call "%temp%\temp.bat"

:RemoveTrailingSpace
if /i "%filesize:~-1%" EQU " " set filesize=%filesize:~0,-1%
if /i "%filesize:~-1%" EQU " " goto:RemoveTrailingSpace

:onemoretime2
set filesize2=%filesize:* =%
set filesize=%filesize2:* =%
if /i "%filesize%" NEQ "%filesize2%" goto:onemoretime2

set filesize=%filesize:,=%
echo %filesize% bytes

SET /a filesizeMB=%filesize%/1024/1024
echo %filesizeMB% MB

SET /a filesizeGB=%filesize%/1024/1024/1024
echo %filesizeGB% GB

Java Try and Catch IOException Problem

Your countLines(String filename) method throws IOException.

You can't use it in a member declaration. You'll need to perform the operation in a main(String[] args) method.

Your main(String[] args) method will get the IOException thrown to it by countLines and it will need to handle or declare it.

Try this to just throw the IOException from main

public class MyClass {
  private int lineCount;
  public static void main(String[] args) throws IOException {
    lineCount = LineCounter.countLines(sFileName);
  }
}

or this to handle it and wrap it in an unchecked IllegalArgumentException:

public class MyClass {
  private int lineCount;
  private String sFileName  = "myfile";
  public static void main(String[] args) throws IOException {
    try {
      lineCount = LineCounter.countLines(sFileName);
     } catch (IOException e) {
       throw new IllegalArgumentException("Unable to load " + sFileName, e);
     }
  }
}

Replacing few values in a pandas dataframe column with another value

You could also pass a dict to the pandas.replace method:

data.replace({
    'column_name': {
        'value_to_replace': 'replace_value_with_this'
    }
})

This has the advantage that you can replace multiple values in multiple columns at once, like so:

data.replace({
    'column_name': {
        'value_to_replace': 'replace_value_with_this',
        'foo': 'bar',
        'spam': 'eggs'
    },
    'other_column_name': {
        'other_value_to_replace': 'other_replace_value_with_this'
    },
    ...
})

How can I dynamically add items to a Java array?

In Java size of array is fixed , but you can add elements dynamically to a fixed sized array using its index and for loop. Please find example below.

package simplejava;

import java.util.Arrays;

/**
 *
 * @author sashant
 */
public class SimpleJava {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here

        try{
            String[] transactions;
            transactions = new String[10];

            for(int i = 0; i < transactions.length; i++){
                transactions[i] = "transaction - "+Integer.toString(i);            
            }

            System.out.println(Arrays.toString(transactions));

        }catch(Exception exc){
            System.out.println(exc.getMessage());
            System.out.println(Arrays.toString(exc.getStackTrace()));
        }
    }

}

replace special characters in a string python

You need to call replace on z and not on str, since you want to replace characters located in the string variable z

removeSpecialChars = z.replace("!@#$%^&*()[]{};:,./<>?\|`~-=_+", " ")

But this will not work, as replace looks for a substring, you will most likely need to use regular expression module re with the sub function:

import re
removeSpecialChars = re.sub("[!@#$%^&*()[]{};:,./<>?\|`~-=_+]", " ", z)

Don't forget the [], which indicates that this is a set of characters to be replaced.

pandas: merge (join) two data frames on multiple columns

Try this

new_df = pd.merge(A_df, B_df,  how='left', left_on=['A_c1','c2'], right_on = ['B_c1','c2'])

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.merge.html

left_on : label or list, or array-like Field names to join on in left DataFrame. Can be a vector or list of vectors of the length of the DataFrame to use a particular vector as the join key instead of columns

right_on : label or list, or array-like Field names to join on in right DataFrame or vector/list of vectors per left_on docs

how to download file using AngularJS and calling MVC API?

string trackPathTemp = track.trackPath;

            //The File Path
            var videoFilePath = HttpContext.Current.Server.MapPath("~/" + trackPathTemp);

            var stream = new FileStream(videoFilePath, FileMode.Open, FileAccess.Read);
            var result = new HttpResponseMessage(HttpStatusCode.OK)
            {
                Content = new StreamContent(stream)
            };
            result.Content.Headers.ContentType = new MediaTypeHeaderValue("video/mp4");
            result.Content.Headers.ContentRange = new ContentRangeHeaderValue(0, stream.Length);
            // result.Content.Headers.Add("filename", "Video.mp4");
            result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
            {
                FileName = "Video.mp4"
            };
            return result;

round value to 2 decimals javascript

Just multiply the number by 100, round, and divide the resulting number by 100.

Docker: unable to prepare context: unable to evaluate symlinks in Dockerfile path: GetFileAttributesEx

The name of the file should be Dockerfile and not .Dockerfile. The file should not have any extension.

How to use glyphicons in bootstrap 3.0

If you are using grunt to build your application, it's possible that during build the paths change. In this case you need to modify your grunt file like this:

copy: {
        main: {
            files: [{
                src: ['fonts/**'],
                dest: 'dist/fonts/',
                filter: 'isFile',
                expand: true,
                flatten: true
            }, {
                src: ['bower_components/font-awesome/fonts/**'],
                dest: 'dist/css/',
                filter: 'isFile',
                expand: true,
                flatten: false
            }]
        }
    },

How to have a default option in Angular.js select box

Using select with ngOptions and setting a default value:

See the ngOptions documentation for more ngOptions usage examples.

_x000D_
_x000D_
angular.module('defaultValueSelect', [])_x000D_
 .controller('ExampleController', ['$scope', function($scope) {_x000D_
   $scope.data = {_x000D_
    availableOptions: [_x000D_
      {id: '1', name: 'Option A'},_x000D_
      {id: '2', name: 'Option B'},_x000D_
      {id: '3', name: 'Option C'}_x000D_
    ],_x000D_
    selectedOption: {id: '2', name: 'Option B'} //This sets the default value of the select in the ui_x000D_
    };_x000D_
}]);
_x000D_
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.0-rc.0/angular.min.js"></script>_x000D_
<body ng-app="defaultValueSelect">_x000D_
  <div ng-controller="ExampleController">_x000D_
  <form name="myForm">_x000D_
    <label for="mySelect">Make a choice:</label>_x000D_
    <select name="mySelect" id="mySelect"_x000D_
      ng-options="option.name for option in data.availableOptions track by option.id"_x000D_
      ng-model="data.selectedOption"></select>_x000D_
  </form>_x000D_
  <hr>_x000D_
  <tt>option = {{data.selectedOption}}</tt><br/>_x000D_
</div>
_x000D_
_x000D_
_x000D_

plnkr.co

Official documentation about HTML SELECT element with angular data-binding.

Binding select to a non-string value via ngModel parsing / formatting:

_x000D_
_x000D_
(function(angular) {_x000D_
  'use strict';_x000D_
angular.module('nonStringSelect', [])_x000D_
  .run(function($rootScope) {_x000D_
    $rootScope.model = { id: 2 };_x000D_
  })_x000D_
  .directive('convertToNumber', function() {_x000D_
    return {_x000D_
      require: 'ngModel',_x000D_
      link: function(scope, element, attrs, ngModel) {_x000D_
        ngModel.$parsers.push(function(val) {_x000D_
          return parseInt(val, 10);_x000D_
        });_x000D_
        ngModel.$formatters.push(function(val) {_x000D_
          return '' + val;_x000D_
        });_x000D_
      }_x000D_
    };_x000D_
  });_x000D_
})(window.angular);
_x000D_
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.0-rc.1/angular.min.js"></script>_x000D_
<body ng-app="nonStringSelect">_x000D_
  <select ng-model="model.id" convert-to-number>_x000D_
  <option value="1">One</option>_x000D_
  <option value="2">Two</option>_x000D_
  <option value="3">Three</option>_x000D_
</select>_x000D_
{{ model }}_x000D_
</body>
_x000D_
_x000D_
_x000D_

plnkr.co

Other example:

_x000D_
_x000D_
angular.module('defaultValueSelect', [])_x000D_
 .controller('ExampleController', ['$scope', function($scope) {_x000D_
   $scope.availableOptions = [_x000D_
     { name: 'Apple', value: 'apple' }, _x000D_
     { name: 'Banana', value: 'banana' }, _x000D_
     { name: 'Kiwi', value: 'kiwi' }_x000D_
   ];_x000D_
   $scope.data = {selectedOption : $scope.availableOptions[1].value};_x000D_
}]);
_x000D_
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.5.0-rc.0/angular.min.js"></script>_x000D_
<body ng-app="defaultValueSelect">_x000D_
  <div ng-controller="ExampleController">_x000D_
  <form name="myForm">_x000D_
    <select ng-model="data.selectedOption" required ng-options="option.value as option.name for option in availableOptions"></select>_x000D_
  </form>  _x000D_
  </div>_x000D_
</body>
_x000D_
_x000D_
_x000D_

jsfiddle

How to get current route in react-router 2.0.0-rc5

Works for me in the same way:

...
<MyComponent {...this.props}>
  <Route path="path1" name="pname1" component="FirstPath">
  ...
</MyComponent>
...

And then, I can access "this.props.location.pathname" in the MyComponent function.

I forgot that it was I am...))) Following link describes more for make navigation bar etc.: react router this.props.location

test attribute in JSTL <c:if> tag

Attributes in JSP tag libraries in general can be either static or resolved at request time. If they are resolved at request time the JSP will resolve their value at runtime and pass the output on to the tag. This means you can put pretty much any JSP code into the attribute and the tag will behave accordingly to what output that produces.

If you look at the jstl taglib docs you can see which attributes are reuest time and which are not. http://java.sun.com/products/jsp/jstl/1.1/docs/tlddocs/index.html

What is the difference between git clone and checkout?

checkout can be use for many case :

1st case : switch between branch in local repository For instance : git checkout exists_branch_to_switch

You can also create new branch and switch out in throught this case with -b

git checkout -b new_branch_to_switch

2nd case : restore file from x rev

git checkout rev file_to_restore ...

Using npm behind corporate proxy .pac

I've just had a very similar problem, where I couldn't get npm to work behind our proxy server.

My username is of the form "domain\username" - including the slash in the proxy configuration resulted in a forward slash appearing. So entering this:

npm config set proxy "http://domain\username:password@servername:port/"

then running this npm config get proxy returns this: http://domain/username:password@servername:port/

Therefore to fix the problem I instead URL encoded the backslash, so entered this:

npm config set proxy "http://domain%5Cusername:password@servername:port/"

and with this the proxy access was fixed.

Convert spark DataFrame column to python list

If you get the error below :

AttributeError: 'list' object has no attribute 'collect'

This code will solve your issues :

mvv_list = mvv_count_df.select('mvv').collect()

mvv_array = [int(i.mvv) for i in mvv_list]

nodeJs callbacks simple example

var myCallback = function(data) {
  console.log('got data: '+data);
};

var usingItNow = function(callback) {
  callback('get it?');
};

Now open node or browser console and paste the above definitions.

Finally use it with this next line:

usingItNow(myCallback);

With Respect to the Node-Style Error Conventions

Costa asked what this would look like if we were to honor the node error callback conventions.

In this convention, the callback should expect to receive at least one argument, the first argument, as an error. Optionally we will have one or more additional arguments, depending on the context. In this case, the context is our above example.

Here I rewrite our example in this convention.

var myCallback = function(err, data) {
  if (err) throw err; // Check for the error and throw if it exists.
  console.log('got data: '+data); // Otherwise proceed as usual.
};

var usingItNow = function(callback) {
  callback(null, 'get it?'); // I dont want to throw an error, so I pass null for the error argument
};

If we want to simulate an error case, we can define usingItNow like this

var usingItNow = function(callback) {
  var myError = new Error('My custom error!');
  callback(myError, 'get it?'); // I send my error as the first argument.
};

The final usage is exactly the same as in above:

usingItNow(myCallback);

The only difference in behavior would be contingent on which version of usingItNow you've defined: the one that feeds a "truthy value" (an Error object) to the callback for the first argument, or the one that feeds it null for the error argument.

open resource with relative path in Java

resourcesloader.class.getClass()

Can be broken down to:

Class<resourcesloader> clazz = resourceloader.class;
Class<Class> classClass = clazz.getClass();

Which means you're trying to load the resource using a bootstrap class.

Instead you probably want something like:

resourcesloader.class.getResource("repository/SSL-Key/cert.jks").toString()

If only javac warned about calling static methods on non-static contexts...

Linux - Install redis-cli only

From http://redis.io/topics/quickstart

wget http://download.redis.io/redis-stable.tar.gz
tar xvzf redis-stable.tar.gz
cd redis-stable
make redis-cli
sudo cp src/redis-cli /usr/local/bin/

With Docker I normally use https://registry.hub.docker.com/_/redis/. If I need to add redis-cli to an image I use the following snippet.

RUN cd /tmp &&\
    curl http://download.redis.io/redis-stable.tar.gz | tar xz &&\
    make -C redis-stable &&\
    cp redis-stable/src/redis-cli /usr/local/bin &&\
    rm -rf /tmp/redis-stable

Best way to require all files from a directory in ruby?

Dir[File.dirname(__FILE__) + '/../lib/*.rb'].each do |file| 
  require File.basename(file, File.extname(file))
end

If you don't strip the extension then you may end up requiring the same file twice (ruby won't realize that "foo" and "foo.rb" are the same file). Requiring the same file twice can lead to spurious warnings (e.g. "warning: already initialized constant").

C fopen vs open

First, there is no particularly good reason to use fdopen if fopen is an option and open is the other possible choice. You shouldn't have used open to open the file in the first place if you want a FILE *. So including fdopen in that list is incorrect and confusing because it isn't very much like the others. I will now proceed to ignore it because the important distinction here is between a C standard FILE * and an OS-specific file descriptor.

There are four main reasons to use fopen instead of open.

  1. fopen provides you with buffering IO that may turn out to be a lot faster than what you're doing with open.
  2. fopen does line ending translation if the file is not opened in binary mode, which can be very helpful if your program is ever ported to a non-Unix environment (though the world appears to be converging on LF-only (except IETF text-based networking protocols like SMTP and HTTP and such)).
  3. A FILE * gives you the ability to use fscanf and other stdio functions.
  4. Your code may someday need to be ported to some other platform that only supports ANSI C and does not support the open function.

In my opinion the line ending translation more often gets in your way than helps you, and the parsing of fscanf is so weak that you inevitably end up tossing it out in favor of something more useful.

And most platforms that support C have an open function.

That leaves the buffering question. In places where you are mainly reading or writing a file sequentially, the buffering support is really helpful and a big speed improvement. But it can lead to some interesting problems in which data does not end up in the file when you expect it to be there. You have to remember to fclose or fflush at the appropriate times.

If you're doing seeks (aka fsetpos or fseek the second of which is slightly trickier to use in a standards compliant way), the usefulness of buffering quickly goes down.

Of course, my bias is that I tend to work with sockets a whole lot, and there the fact that you really want to be doing non-blocking IO (which FILE * totally fails to support in any reasonable way) with no buffering at all and often have complex parsing requirements really color my perceptions.

Spring MVC - How to return simple String as JSON in Rest Controller

Add @ResponseBody annotation, which will write return data in output stream.

How do I call a function inside of another function?

_x000D_
_x000D_
function function_one()_x000D_
{_x000D_
    alert("The function called 'function_one' has been called.")_x000D_
    //Here u would like to call function_two._x000D_
    function_two(); _x000D_
}_x000D_
_x000D_
function function_two()_x000D_
{_x000D_
    alert("The function called 'function_two' has been called.")_x000D_
}
_x000D_
_x000D_
_x000D_

Which regular expression operator means 'Don't' match this character?

[^] ( within [ ] ) is negation in regular expression whereas ^ is "begining of string"

[^a-z] matches any single character that is not from "a" to "z"

^[a-z] means string starts with from "a" to "z"

Reference

How do I share a global variable between c files?

If you want to use global variable i of file1.c in file2.c, then below are the points to remember:

  1. main function shouldn't be there in file2.c
  2. now global variable i can be shared with file2.c by two ways:
    a) by declaring with extern keyword in file2.c i.e extern int i;
    b) by defining the variable i in a header file and including that header file in file2.c.

Inserting the iframe into react component

With ES6 you can now do it like this

Example Codepen URl to load

const iframe = '<iframe height="265" style="width: 100%;" scrolling="no" title="fx." src="//codepen.io/ycw/embed/JqwbQw/?height=265&theme-id=0&default-tab=js,result" frameborder="no" allowtransparency="true" allowfullscreen="true">See the Pen <a href="https://codepen.io/ycw/pen/JqwbQw/">fx.</a> by ycw(<a href="https://codepen.io/ycw">@ycw</a>) on <a href="https://codepen.io">CodePen</a>.</iframe>'; 

A function component to load Iframe

function Iframe(props) {
  return (<div dangerouslySetInnerHTML={ {__html:  props.iframe?props.iframe:""}} />);
}

Usage:

import React from "react";
import ReactDOM from "react-dom";
function App() {
  return (
    <div className="App">
      <h1>Iframe Demo</h1>
      <Iframe iframe={iframe} />,
    </div>
  );
}

const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);

Edit on CodeSandbox:

https://codesandbox.io/s/react-iframe-demo-g3vst

An existing connection was forcibly closed by the remote host

I got the same issue while using .NET Framework 4.5. However, when I update the .NET version to 4.7.2 connection issue was resolved. Maybe this is due to SecurityProtocol support issue.

Rollback one specific migration in Laravel

INSERT INTO homestead.bb_migrations (`migration`, `batch`)  VALUES ('2016_01_21_064436_create_victory_point_balance_table', '2')

something like this

Convert Pixels to Points

System.Drawing.Graphics has DpiX and DpiY properties. DpiX is pixels per inch horizontally. DpiY is pixels per inch vertically. Use those to convert from points (72 points per inch) to pixels.

Ex: 14 horizontal points = (14 * DpiX) / 72 pixels

Multiple Python versions on the same machine?

I'm using Mac & the best way that worked for me is using pyenv!

The commands below are for Mac but pretty similar to Linux (see the links below)

#Install pyenv
brew update
brew install pyenv

Let's say you have python 3.6 as your primary version on your mac:

python --version 

Output:

Python <your current version>

Now Install python 3.7, first list all

pyenv install -l

Let's take 3.7.3:

pyenv install 3.7.3

Make sure to run this in the Terminal (add it to ~/.bashrc or ~/.zshrc):

export PATH="/Users/username/.pyenv:$PATH"
eval "$(pyenv init -)"

Now let's run it only on the opened terminal/shell:

pyenv shell 3.7.3

Now run

python --version

Output:

Python 3.7.3

And not less important unset it in the opened shell/iTerm:

pyenv shell --unset

You can run it globally or locally as well

Floating point exception( core dump

You are getting Floating point exception because Number % i, when i is 0:

int Is_Prime( int Number ){

  int i ;

  for( i = 0 ; i < Number / 2 ; i++ ){

    if( Number % i != 0 ) return -1 ;

  }

  return Number ;

}

Just start the loop at i = 2. Since i = 1 in Number % i it always be equal to zero, since Number is a int.

Most efficient way to find mode in numpy array

A neat solution that only uses numpy (not scipy nor the Counter class):

A = np.array([[1,3,4,2,2,7], [5,2,2,1,4,1], [3,3,2,2,1,1]])

np.apply_along_axis(lambda x: np.bincount(x).argmax(), axis=0, arr=A)

array([1, 3, 2, 2, 1, 1])

Detect changed input text box

Text inputs do not fire the change event until they lose focus. Click outside of the input and the alert will show.

If the callback should fire before the text input loses focus, use the .keyup() event.

How to uninstall pip on OSX?

In my case I ran the following command and it worked (not that I was expecting it to):

sudo pip uninstall pip

Which resulted in:

Uninstalling pip-6.1.1:
  /Library/Python/2.7/site-packages/pip-6.1.1.dist-info/DESCRIPTION.rst
  /Library/Python/2.7/site-packages/pip-6.1.1.dist-info/METADATA
  /Library/Python/2.7/site-packages/pip-6.1.1.dist-info/RECORD
  <and all the other stuff>
  ...

  /usr/local/bin/pip
  /usr/local/bin/pip2
  /usr/local/bin/pip2.7
Proceed (y/n)? y
  Successfully uninstalled pip-6.1.1

What are the "standard unambiguous date" formats for string-to-date conversion in R?

This is documented behavior. From ?as.Date:

format: A character string. If not specified, it will try '"%Y-%m-%d"' then '"%Y/%m/%d"' on the first non-'NA' element, and give an error if neither works.

as.Date("01 Jan 2000") yields an error because the format isn't one of the two listed above. as.Date("01/01/2000") yields an incorrect answer because the date isn't in one of the two formats listed above.

I take "standard unambiguous" to mean "ISO-8601" (even though as.Date isn't that strict, as "%m/%d/%Y" isn't ISO-8601).

If you receive this error, the solution is to specify the format your date (or datetimes) are in, using the formats described in ?strptime. Be sure to use particular care if your data contain day/month names and/or abbreviations, as the conversion will depend on your locale (see the examples in ?strptime and read ?LC_TIME).

How to install all required PHP extensions for Laravel?

Laravel Server Requirements mention that BCMath, Ctype, JSON, Mbstring, OpenSSL, PDO, Tokenizer, and XML extensions are required. Most of the extensions are installed and enabled by default.

You can run the following command in Ubuntu to make sure the extensions are installed.

sudo apt install openssl php-common php-curl php-json php-mbstring php-mysql php-xml php-zip

PHP version specific installation (if PHP 7.4 installed)

sudo apt install php7.4-common php7.4-bcmath openssl php7.4-json php7.4-mbstring

You may need other PHP extensions for your composer packages. Find from links below.

PHP extensions for Ubuntu 20.04 LTS (Focal Fossa)

PHP extensions for Ubuntu 18.04 LTS (Bionic)

PHP extensions for Ubuntu 16.04 LTS (Xenial)

How should we manage jdk8 stream for null values

If you just want to filter null values out of a stream, you can simply use a method reference to java.util.Objects.nonNull(Object). From its documentation:

This method exists to be used as a Predicate, filter(Objects::nonNull)

For example:

List<String> list = Arrays.asList( null, "Foo", null, "Bar", null, null);

list.stream()
    .filter( Objects::nonNull )  // <-- Filter out null values
    .forEach( System.out::println );

This will print:

Foo
Bar

jQuery selector for inputs with square brackets in the name attribute

Per the jQuery documentation, try this:

$('input[inputName\\[\\]=someValue]')

[EDIT] However, I'm not sure that's the right syntax for your selector. You probably want:

$('input[name="inputName[]"][value="someValue"]')

Extracting first n columns of a numpy matrix

I know this is quite an old question -

A = [[1, 2, 3],
     [4, 5, 6],
     [7, 8, 9]]

Let's say, you want to extract the first 2 rows and first 3 columns

A_NEW = A[0:2, 0:3]
A_NEW = [[1, 2, 3],
         [4, 5, 6]]

Understanding the syntax

A_NEW = A[start_index_row : stop_index_row, 
          start_index_column : stop_index_column)]

If one wants row 2 and column 2 and 3

A_NEW = A[1:2, 1:3]

Reference the numpy indexing and slicing article - Indexing & Slicing

C pass int array pointer as parameter into a function

Make use of *(B) instead of *B[0]. Here, *(B+i) implies B[i] and *(B) implies B[0], that is
*(B+0)=*(B)=B[0].

#include <stdio.h>

int func(int *B){
    *B = 5;     
    // if you want to modify ith index element in the array just do *(B+i)=<value>
}

int main(void){

    int B[10] = {};
    printf("b[0] = %d\n\n", B[0]);
    func(B);
    printf("b[0] = %d\n\n", B[0]);
    return 0;
}

PHP json_decode() returns NULL with valid JSON?

Here you can find little JSON wrapper with corrective actions that addresses BOM and non-ASCI issue: https://stackoverflow.com/a/43694325/2254935

Failed to connect to camera service

Make sure to call the release() method to release the camera when it is no longer needed, or you will not be able to use the camera. Perhaps as a sanity check, see if your regular camera works. If it says it fails, then your previous attempts at runni

docker: Error response from daemon: Get https://registry-1.docker.io/v2/: Service Unavailable. IN DOCKER , MAC

  1. ReCheck Proxy Settings with following commands

    docker info | grep Proxy

  2. Check VPN Connectivity

  3. If VPN not using CHECK NET connectivity

  4. Reinsrtall Docker and repeat above steps.

  5. Enjoy

How do I fix "for loop initial declaration used outside C99 mode" GCC error?

I'd try to declare i outside of the loop!

Good luck on solving 3n+1 :-)

Here's an example:

#include <stdio.h>

int main() {

   int i;

   /* for loop execution */
   for (i = 10; i < 20; i++) {
       printf("i: %d\n", i);
   }   

   return 0;
}

Read more on for loops in C here.

How to check the version before installing a package using apt-get?

on debian :

apt list --upgradable

gives the list with package, version to be upgraded, and actual version of the package.

result :

base-files/stable 8+deb8u8 amd64 [upgradable from: 8+deb8u7]
bind9-host/stable 1:9.9.5.dfsg-9+deb8u11 amd64 [upgradable from: 1:9.9.5.dfsg-9+deb8u9]
ca-certificates/stable 20141019+deb8u3 all [upgradable from: 20141019+deb8u2]
certbot/jessie-backports 0.10.2-1~bpo8+1 all [upgradable from: 0.8.1-2~bpo8+1]
dnsutils/stable 1:9.9.5.dfsg-9+deb8u11 amd64 [upgradable from: 1:9.9.5.dfsg-9+deb8u9]

PHP Fatal error: Using $this when not in object context

You are calling a non-static method :

public function foobarfunc() {
    return $this->foo();
}

Using a static-call :

foobar::foobarfunc();

When using a static-call, the function will be called (even if not declared as static), but, as there is no instance of an object, there is no $this.

So :

  • You should not use static calls for non-static methods
  • Your static methods (or statically-called methods) can't use $this, which normally points to the current instance of the class, as there is no class instance when you're using static-calls.


Here, the methods of your class are using the current instance of the class, as they need to access the $foo property of the class.

This means your methods need an instance of the class -- which means they cannot be static.

This means you shouldn't use static calls : you should instanciate the class, and use the object to call the methods, like you did in your last portion of code :

$foobar = new foobar();
$foobar->foobarfunc();


For more informations, don't hesitate to read, in the PHP manual :


Also note that you probably don't need this line in your __construct method :

global $foo;

Using the global keyword will make the $foo variable, declared outside of all functions and classes, visibile from inside that method... And you probably don't have such a $foo variable.

To access the $foo class-property, you only need to use $this->foo, like you did.