Programs & Examples On #Division

In mathematics, division (÷) is an arithmetic elementary operation.

Python3 integer division

Try this:

a = 1
b = 2
int_div  = a // b

Is multiplication and division using shift operators in C actually faster?

Short answer: Not likely.

Long answer: Your compiler has an optimizer in it that knows how to multiply as quickly as your target processor architecture is capable. Your best bet is to tell the compiler your intent clearly (i.e. i*2 rather than i << 1) and let it decide what the fastest assembly/machine code sequence is. It's even possible that the processor itself has implemented the multiply instruction as a sequence of shifts & adds in microcode.

Bottom line--don't spend a lot of time worrying about this. If you mean to shift, shift. If you mean to multiply, multiply. Do what is semantically clearest--your coworkers will thank you later. Or, more likely, curse you later if you do otherwise.

How can I multiply and divide using only bit shifting and adding?

The answer by Andrew Toulouse can be extended to division.

The division by integer constants is considered in details in the book "Hacker's Delight" by Henry S. Warren (ISBN 9780201914658).

The first idea for implementing division is to write the inverse value of the denominator in base two.

E.g., 1/3 = (base-2) 0.0101 0101 0101 0101 0101 0101 0101 0101 .....

So, a/3 = (a >> 2) + (a >> 4) + (a >> 6) + ... + (a >> 30) for 32-bit arithmetics.

By combining the terms in an obvious manner we can reduce the number of operations:

b = (a >> 2) + (a >> 4)

b += (b >> 4)

b += (b >> 8)

b += (b >> 16)

There are more exciting ways to calculate division and remainders.

EDIT1:

If the OP means multiplication and division of arbitrary numbers, not the division by a constant number, then this thread might be of use: https://stackoverflow.com/a/12699549/1182653

EDIT2:

One of the fastest ways to divide by integer constants is to exploit the modular arithmetics and Montgomery reduction: What's the fastest way to divide an integer by 3?

What is the reason for having '//' in Python?

// can be considered an alias to math.floor() for divisions with return value of type float. It operates as no-op for divisions with return value of type int.

import math
# let's examine `float` returns
# -------------------------------------
# divide
>>> 1.0 / 2
0.5
# divide and round down
>>> math.floor(1.0/2)
0.0
# divide and round down
>>> 1.0 // 2
0.0

# now let's examine `integer` returns
# -------------------------------------
>>> 1/2
0
>>> 1//2
0

How can I calculate divide and modulo for integers in C#?

Before asking questions of this kind, please check MSDN documentation.

When you divide two integers, the result is always an integer. For example, the result of 7 / 3 is 2. To determine the remainder of 7 / 3, use the remainder operator (%).

int a = 5;
int b = 3;

int div = a / b; //quotient is 1
int mod = a % b; //remainder is 2

How to check if number is divisible by a certain number?

n % x == 0

Means that n can be divided by x. So... for instance, in your case:

boolean isDivisibleBy20 = number % 20 == 0;

Also, if you want to check whether a number is even or odd (whether it is divisible by 2 or not), you can use a bitwise operator:

boolean even = (number & 1) == 0;
boolean odd  = (number & 1) != 0;

Division in Python 2.7. and 3.3

In Python 2.x, make sure to have at least one operand of your division in float. Multiple ways you may achieve this as the following examples:

20. / 15
20 / float(15)

Divide a number by 3 without using *, /, +, -, % operators

Using BC Math in PHP:

<?php
    $a = 12345;
    $b = bcdiv($a, 3);   
?>

MySQL (it's an interview from Oracle)

> SELECT 12345 DIV 3;

Pascal:

a:= 12345;
b:= a div 3;

x86-64 assembly language:

mov  r8, 3
xor  rdx, rdx   
mov  rax, 12345
idiv r8

Simple division in Java - is this a bug or a feature?

You've used integers in the expression 7/10, and integer 7 divided by integer 10 is zero.

What you're expecting is floating point division. Any of the following would evaluate the way you expected:

7.0 / 10
7 / 10.0
7.0 / 10.0
7 / (double) 10

How to find the remainder of a division in C?

Use the modulus operator %, it returns the remainder.

int a = 5;
int b = 3;

if (a % b != 0) {
   printf("The remainder is: %i", a%b);
}

How can I do division with variables in a Linux shell?

To get the numbers after decimal point, you can do this:-

read num1 num2
div=`echo $num1 / $num2 | bc -l`
echo $div

Why is division in Ruby returning an integer instead of decimal value?

You can check it with irb:

$ irb
>> 2 / 3
=> 0
>> 2.to_f / 3
=> 0.666666666666667
>> 2 / 3.to_f
=> 0.666666666666667

How to do integer division in javascript (Getting division answer in int not float)?

var answer = Math.floor(x)

I sincerely hope this will help future searchers when googling for this common question.

How to get a float result by dividing two integer values using T-SQL?

It's not necessary to cast both of them. Result datatype for a division is always the one with the higher data type precedence. Thus the solution must be:

SELECT CAST(1 AS float) / 3

or

SELECT 1 / CAST(3 AS float)

C++ Best way to get integer division and remainder

In addition to the aforementioned std::div family of functions, there is also the std::remquo family of functions, return the rem-ainder and getting the quo-tient via a passed-in pointer.

[Edit:] It looks like std::remquo doesn't really return the quotient after all.

How do I divide so I get a decimal value?

In your example, Java is performing integer arithmetic, rounding off the result of the division.

Based on your question, you would like to perform floating-point arithmetic. To do so, at least one of your terms must be specified as (or converted to) floating-point:

Specifying floating point:

3.0/2
3.0/2.0
3/2.0

Converting to floating point:

int a = 2;
int b = 3;
float q = ((float)a)/b;

or

double q = ((double)a)/b;

(See Java Traps: double and Java Floating-Point Number Intricacies for discussions on float and double)

Python integer division yields float

According to Python3 documentation,python when divided by integer,will generate float despite expected to be integer.

For exclusively printing integer,use floor division method. Floor division is rounding off zero and removing decimal point. Represented by //

Hence,instead of 2/2 ,use 2//2

You can also import division from __future__ irrespective of using python2 or python3.

Hope it helps!

How can I force division to be floating point? Division keeps rounding down to 0?

from operator import truediv

c = truediv(a, b)

where a is dividend and b is the divisor. This function is handy when quotient after division of two integers is a float.

How Does Modulus Divison Work

It's simple, Modulus operator(%) returns remainder after integer division. Let's take the example of your question. How 27 % 16 = 11? When you simply divide 27 by 16 i.e (27/16) then you get remainder as 11, and that is why your answer is 11.

Python: Remove division decimal

>>> int(2.0)

You will get the answer as 2

Why does integer division in C# return an integer and not a float?

Since you don't use any suffix, the literals 13 and 4 are interpreted as integer:

Manual:

If the literal has no suffix, it has the first of these types in which its value can be represented: int, uint, long, ulong.

Thus, since you declare 13 as integer, integer division will be performed:

Manual:

For an operation of the form x / y, binary operator overload resolution is applied to select a specific operator implementation. The operands are converted to the parameter types of the selected operator, and the type of the result is the return type of the operator.

The predefined division operators are listed below. The operators all compute the quotient of x and y.

Integer division:

int operator /(int x, int y);
uint operator /(uint x, uint y);
long operator /(long x, long y);
ulong operator /(ulong x, ulong y);

And so rounding down occurs:

The division rounds the result towards zero, and the absolute value of the result is the largest possible integer that is less than the absolute value of the quotient of the two operands. The result is zero or positive when the two operands have the same sign and zero or negative when the two operands have opposite signs.

If you do the following:

int x = 13f / 4f;

You'll receive a compiler error, since a floating-point division (the / operator of 13f) results in a float, which cannot be cast to int implicitly.

If you want the division to be a floating-point division, you'll have to make the result a float:

float x = 13 / 4;

Notice that you'll still divide integers, which will implicitly be cast to float: the result will be 3.0. To explicitly declare the operands as float, using the f suffix (13f, 4f).

How to define servlet filter order of execution using annotations in WAR

  1. Make the servlet filter implement the spring Ordered interface.
  2. Declare the servlet filter bean manually in configuration class.
    import org.springframework.core.Ordered;
    
    public class MyFilter implements Filter, Ordered {

        @Override
        public void init(FilterConfig filterConfig) {
            // do something
        }

        @Override
        public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
            // do something
        }

        @Override
        public void destroy() {
            // do something
        }

        @Override
        public int getOrder() {
            return -100;
        }
    }


    import org.springframework.context.annotation.ComponentScan;
    import org.springframework.context.annotation.Configuration;

    @Configuration
    @ComponentScan
    public class MyAutoConfiguration {

        @Bean
        public MyFilter myFilter() {
            return new MyFilter();
        }
    }

jQuery: selecting each td in a tr

expanding on the answer above the 'each' function will return you the table-cell html object. wrapping that in $() will then allow you to perform jquery actions on it.

$(this).find('td').each (function( column, td) {
  $(td).blah
});  

How to determine previous page URL in Angular?

I had some struggle to access the previous url inside a guard.
Without implementing a custom solution, this one is working for me.

public constructor(private readonly router: Router) {
};

public ngOnInit() {
   this.router.getCurrentNavigation().previousNavigation.initialUrl.toString();
}

The initial url will be the previous url page.

Cannot perform runtime binding on a null reference, But it is NOT a null reference

This error happens when you have a ViewBag Non-Existent in your razor code calling a method.

Controller

public ActionResult Accept(int id)
{
    return View();
}

razor:

<div class="form-group">
      @Html.LabelFor(model => model.ToId, "To", htmlAttributes: new { @class = "control-label col-md-2" })
     <div class="col-md-10">
           @Html.Flag(Model.from)
     </div>
</div>
<div class="form-group">
     <div class="col-md-10">
          <input value="@ViewBag.MaximounAmount.ToString()" />@* HERE is the error *@ 
     </div>
</div>

For some reason, the .net aren't able to show the error in the correct line.

Normally this causes a lot of wasted time.

Python handling socket.error: [Errno 104] Connection reset by peer

There is a way to catch the error directly in the except clause with ConnectionResetError, better to isolate the right error. This example also catches the timeout.

from urllib.request import urlopen 
from socket import timeout

url = "http://......"
try: 
    string = urlopen(url, timeout=5).read()
except ConnectionResetError:
    print("==> ConnectionResetError")
    pass
except timeout: 
    print("==> Timeout")
    pass

How do I load a file from resource folder?

if you are loading file in static method then ClassLoader classLoader = getClass().getClassLoader(); this might give you an error.

You can try this e.g. file you want to load from resources is resources >> Images >> Test.gif

import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;

Resource resource = new ClassPathResource("Images/Test.gif");

    File file = resource.getFile();

What is the meaning of "$" sign in JavaScript

From the jQuery documentation describing the jQuery Core Object:

Many developers prefix a $ to the name of variables that contain jQuery objects in order to help differentiate. There is nothing magic about this practice – it just helps some people keep track of what different variables contain.

get list of pandas dataframe columns based on data type

You can use boolean mask on the dtypes attribute:

In [11]: df = pd.DataFrame([[1, 2.3456, 'c']])

In [12]: df.dtypes
Out[12]: 
0      int64
1    float64
2     object
dtype: object

In [13]: msk = df.dtypes == np.float64  # or object, etc.

In [14]: msk
Out[14]: 
0    False
1     True
2    False
dtype: bool

You can look at just those columns with the desired dtype:

In [15]: df.loc[:, msk]
Out[15]: 
        1
0  2.3456

Now you can use round (or whatever) and assign it back:

In [16]: np.round(df.loc[:, msk], 2)
Out[16]: 
      1
0  2.35

In [17]: df.loc[:, msk] = np.round(df.loc[:, msk], 2)

In [18]: df
Out[18]: 
   0     1  2
0  1  2.35  c

How can I find the number of elements in an array?

i mostly found a easy way to execute the length of array inside a loop just like that

 int array[] = {10, 20, 30, 40};
 int i;
 for (i = 0; i < array[i]; i++) {
    printf("%d\n", array[i]);
 }

How to check for null/empty/whitespace values with a single test?

While checking null or Empty value for a column, I noticed that there are some support concerns in various Databases.

Every Database doesn't support TRIM method.

Below is the matrix just to understand the supported methods by different databases.

The TRIM function in SQL is used to remove specified prefix or suffix from a string. The most common pattern being removed is white spaces. This function is called differently in different databases:

  • MySQL: TRIM(), RTRIM(), LTRIM()
  • Oracle: RTRIM(), LTRIM()
  • SQL Server: TRIM(), RTRIM(), LTRIM()

How to Check Empty/Null/Whitespace :-

Below are two different ways according to different Databases-

The syntax for these trim functions are:

  1. Use of Trim to check-

    SELECT FirstName FROM UserDetails WHERE TRIM(LastName) IS NULL

  2. Use of LTRIM & RTRIM to check-

    SELECT FirstName FROM UserDetails WHERE LTRIM(RTRIM(LastName)) IS NULL

Above both ways provide same result just use based on your DataBase support. It Just returns the FirstName from UserDetails table if it has an empty LastName

Hoping this will help others too :)

Order by descending date - month, day and year

If you restructured your date format into YYYY/MM/DD then you can use this simple string ordering to achieve the formating you need.

Alternatively, using the SUBSTR(store_name,start,length) command you should be able to restructure the sorting term into the above format

perhaps using the following

SELECT     *
FROM         vw_view
ORDER BY SUBSTR(EventDate,6,4) + SUBSTR(EventDate, 0, 5) DESC

Count number of files within a directory in Linux?

this is one:

ls -l . | egrep -c '^-'

Note:

ls -1 | wc -l

Which means: ls: list files in dir

-1: (that's a ONE) only one entry per line. Change it to -1a if you want hidden files too

|: pipe output onto...

wc: "wordcount"

-l: count lines.

How to prevent a file from direct URL Access?

rosipov's rule works great!

I use it on live sites to display a blank or special message ;) in place of a direct access attempt to files I'd rather to protect a bit from direct view. I think it's more fun than a 403 Forbidden.

So taking rosipov's rule to redirect any direct request to {gif,jpg,js,txt} files to 'messageforcurious' :

RewriteEngine on 
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain\.ltd [NC] 
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain\.ltd.*$ [NC] 
RewriteRule \.(gif|jpg|js|txt)$ /messageforcurious [L]

I see it as a polite way to disallow direct acces to, say, a CMS sensible files like xml, javascript... with security in mind: To all these bots scrawling the web nowadays, I wonder what their algo will make from my 'messageforcurious'.

Force "portrait" orientation mode

According to Android's documentation, you should also often include screenSize as a possible configuration change.

android:configChanges="orientation|screenSize"

If your application targets API level 13 or higher (as declared by the minSdkVersion and targetSdkVersion attributes), then you should also declare the "screenSize" configuration, because it also changes when a device switches between portrait and landscape orientations.

Also, if you all include value keyboardHidden in your examples, shouldn't you then also consider locale, mcc, fontScale, keyboard and others?..

How to move a git repository into another directory and make that directory a git repository?

I am no expert, but I copy the .git folder to a new folder, then invoke: git reset --hard

using mailto to send email with an attachment

what about this

<FORM METHOD="post" ACTION="mailto:[email protected]" ENCTYPE="multipart/form-data">
Attachment: <INPUT TYPE="file" NAME="attachedfile" MAXLENGTH=50 ALLOW="text/*" >
 <input type="submit" name="submit" id="submit" value="Email"/>
</FORM>

How to install PyQt5 on Windows?

I found a partial solution...

Steps to install pyQt5 (with VS 2012) on Windows:

1) Install the binary file Qt 5.0.2 for Windows 64-bit (VS 2012, 500 MB) from here.

2) Get sip-4.14.7 (development snapshot) from here.

3) Extract the file and open the Developer Command Prompt for VS2012.

4) Execute these commands (in sip folder):

python configure.py
nmake
nmake install

5) Get the pyQt5 from here.

6) Extract the file and open the VS2012 x64 Native Tools Command Prompt.

7) Execute these commands:

python configure.py

UPDATE: When execute these commands below is not working:

nmake
nmake install

Solution: I will try use pyQt4 with Qt5... because pyQt5 is in development and doesn't have support/documentation yet.

SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed

The reason that you get this error on OSX is the rvm-installed ruby.

If you run into this issue on OSX you can find a really broad explanation of it in this blog post:

http://toadle.me/2015/04/16/fixing-failing-ssl-verification-with-rvm.html

The short version is that, for some versions of Ruby, RVM downloads pre-compiled binaries, which look for certificates in the wrong location. By forcing RVM to download the source and compile on your own machine, you ensure that the configuration for the certificate location is correct.

The command to do this is:

rvm install 2.2.0 --disable-binary

if you already have the version in question, you can re-install it with:

rvm reinstall 2.2.0 --disable-binary

(obviously, substitute your ruby version as needed).

In a Git repository, how to properly rename a directory?

You can rename the directory using the file system. Then you can do git rm <old directory> and git add <new directory> (Help page). Then you can commit and push.

Git will detect that the contents are the same and that it's just a rename operation, and it'll appear as a rename entry in the history. You can check that this is the case before the commit using git status

Why is JsonRequestBehavior needed?

Improving upon the answer of @Arjen de Mooij a bit by making the AllowJsonGetAttribute applicable to mvc-controllers (not just individual action-methods):

using System.Web.Mvc;
public sealed class AllowJsonGetAttribute : ActionFilterAttribute, IActionFilter
{
    void IActionFilter.OnActionExecuted(ActionExecutedContext context)
    {
        var jsonResult = context.Result as JsonResult;
        if (jsonResult == null) return;

        jsonResult.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
    }

    public override void OnResultExecuting(ResultExecutingContext filterContext)
    {
        var jsonResult = filterContext.Result as JsonResult;
        if (jsonResult == null) return;

        jsonResult.JsonRequestBehavior = JsonRequestBehavior.AllowGet;
        base.OnResultExecuting(filterContext);
    }
}

Read text file into string. C++ ifstream

getline(fin, buffer, '\n')
where fin is opened file(ifstream object) and buffer is of string/char type where you want to copy line.

Thymeleaf using path variables to th:href

I think you can try this:

<a th:href="${'/category/edit/' + {category.id}}">view</a>

Or if you have "idCategory" this:

<a th:href="${'/category/edit/' + {category.idCategory}}">view</a>

Extracting Ajax return data in jQuery

You may also use the jQuery context parameter. Link to docs

Selector Context

By default, selectors perform their searches within the DOM starting at the document root. However, an alternate context can be given for the search by using the optional second parameter to the $() function

Therefore you could also have:

success: function(data){
    var oneval = $('#one',data).text();
    var subval = $('#sub',data).text();
}

Border around tr element doesn't show?

Add this to the stylesheet:

table {
  border-collapse: collapse;
}

JSFiddle.

The reason why it behaves this way is actually described pretty well in the specification:

There are two distinct models for setting borders on table cells in CSS. One is most suitable for so-called separated borders around individual cells, the other is suitable for borders that are continuous from one end of the table to the other.

... and later, for collapse setting:

In the collapsing border model, it is possible to specify borders that surround all or part of a cell, row, row group, column, and column group.

How do you make strings "XML safe"?

If at all possible, its always a good idea to create your XML using the XML classes rather than string manipulation - one of the benefits being that the classes will automatically escape characters as needed.

How to use Tomcat 8 in Eclipse?

I follow Jason's step, but not works.

And then I find the WTP Update site http://download.eclipse.org/webtools/updates/.

Help -> Install new software -> Add > WTP:http://download.eclipse.org/webtools/updates/ -> OK

Then Help -> Check for update, just works, I don't know whether Jason's affect this .

How to increase apache timeout directive in .htaccess?

Just in case this helps anyone else:

If you're going to be adding the TimeOut directive, and your website uses multiple vhosts (eg. one for port 80, one for port 443), then don't forget to add the directive to all of them!

How to write to the Output window in Visual Studio?

Use OutputDebugString instead of afxDump.

Example:

#define _TRACE_MAXLEN 500

#if _MSC_VER >= 1900
#define _PRINT_DEBUG_STRING(text) OutputDebugString(text)
#else // _MSC_VER >= 1900
#define _PRINT_DEBUG_STRING(text) afxDump << text
#endif // _MSC_VER >= 1900

void MyTrace(LPCTSTR sFormat, ...)
{
    TCHAR text[_TRACE_MAXLEN + 1];
    memset(text, 0, _TRACE_MAXLEN + 1);
    va_list args;
    va_start(args, sFormat);
    int n = _vsntprintf(text, _TRACE_MAXLEN, sFormat, args);
    va_end(args);
    _PRINT_DEBUG_STRING(text);
    if(n <= 0)
        _PRINT_DEBUG_STRING(_T("[...]"));
}

How to list imported modules?

let say you've imported math and re:

>>import math,re

now to see the same use

>>print(dir())

If you run it before the import and after the import, one can see the difference.

How to pass parameters in GET requests with jQuery

Had the same problem where I specified data but the browser was sending requests to URL ending with [Object object].

You should have processData set to true.

processData: true, // You should comment this out if is false or set to true

How to revert uncommitted changes including files and folders?

git clean -fd

didn't help, new files remained. What I did is totally deleting all the working tree and then

git reset --hard

See "How do I clear my local working directory in git?" for advice to add the -x option to clean:

git clean -fdx

Note -x flag will remove all files ignored by Git so be careful (see discussion in the answer I refer to).

How do I request a file but not save it with Wget?

You can use -O- (uppercase o) to redirect content to the stdout (standard output) or to a file (even special files like /dev/null /dev/stderr /dev/stdout )

wget -O- http://yourdomain.com

Or:

wget -O- http://yourdomain.com > /dev/null

Or: (same result as last command)

wget -O/dev/null http://yourdomain.com

HTML image bottom alignment inside DIV container

This is your code: http://jsfiddle.net/WSFnX/

Using display: table-cell is fine, provided that you're aware that it won't work in IE6/7. Other than that, it's safe: Is there a disadvantage of using `display:table-cell`on divs?

To fix the space at the bottom, add vertical-align: bottom to the actual imgs:

http://jsfiddle.net/WSFnX/1/

Removing the space between the images boils down to this: bikeshedding CSS3 property alternative?

So, here's a demo with the whitespace removed in your HTML: http://jsfiddle.net/WSFnX/4/

Description for event id from source cannot be found

How about a real world solution.

If all you need is a "quick and dirty" way to write something to the event log without registering "custom sources" (requires admin rights), or providing "message files" (requires work and headache) just do this:

EventLog.WriteEntry(
    ".NET Runtime", //magic
    "Your error message goes here!!",
    EventLogEntryType.Warning,
    1000); //magic

This way you'll be writing to an existing "Application" log without the annoying "The description for Event ID 0 cannot be found"

If you want the "magic" part explained I blogged about it here

Byte Array and Int conversion in Java

I found a simple way in com.google.common.primitives which is in the [Maven:com.google.guava:guava:12.0.1]

long newLong = Longs.fromByteArray(oldLongByteArray);
int newInt = Ints.fromByteArray(oldIntByteArray);

Have a nice try :)

Java file path in Linux

I think Todd is correct, but I think there's one other thing you should consider. You can reliably get the home directory from the JVM at runtime, and then you can create files objects relative to that location. It's not that much more trouble, and it's something you'll appreciate if you ever move to another computer or operating system.

File homedir = new File(System.getProperty("user.home"));
File fileToRead = new File(homedir, "java/ex.txt");

Differences between SP initiated SSO and IDP initiated SSO

https://support.procore.com/faq/what-is-the-difference-between-sp-and-idp-initiated-sso

There is much more to this but this is a high level overview on which is which.

Procore supports both SP- and IdP-initiated SSO:

Identity Provider Initiated (IdP-initiated) SSO. With this option, your end users must log into your Identity Provider's SSO page (e.g., Okta, OneLogin, or Microsoft Azure AD) and then click an icon to log into and open the Procore web application. To configure this solution, see Configure IdP-Initiated SSO for Microsoft Azure AD, Configure Procore for IdP-Initated Okta SSO, or Configure IdP-Initiated SSO for OneLogin. OR Service Provider Initiated (SP-initiated) SSO. Referred to as Procore-initiated SSO, this option gives your end users the ability to sign into the Procore Login page and then sends an authorization request to the Identify Provider (e.g., Okta, OneLogin, or Microsoft Azure AD). Once the IdP authenticates the user's identify, the user is logged into Procore. To configure this solution, see Configure Procore-Initiated SSO for Microsoft Azure Active Directory, Configure Procore-Initiated SSO for Okta, or Configure Procore-Initiated SSO for OneLogin.

How to turn on WCF tracing?

Instead of you manual adding the tracing enabling bit into web.config you can also try using the WCF configuration editor which comes with VS SDK to enable tracing

https://stackoverflow.com/a/16715631/2218571

Java decimal formatting using String.format?

You want java.text.DecimalFormat

How to implement a Keyword Search in MySQL?

I will explain the method i usally prefer:

First of all you need to take into consideration that for this method you will sacrifice memory with the aim of gaining computation speed. Second you need to have a the right to edit the table structure.

1) Add a field (i usually call it "digest") where you store all the data from the table.

The field will look like:

"n-n1-n2-n3-n4-n5-n6-n7-n8-n9" etc.. where n is a single word

I achieve this using a regular expression thar replaces " " with "-". This field is the result of all the table data "digested" in one sigle string.

2) Use the LIKE statement %keyword% on the digest field:

SELECT * FROM table WHERE digest LIKE %keyword%

you can even build a qUery with a little loop so you can search for multiple keywords at the same time looking like:

SELECT * FROM table WHERE 
 digest LIKE %keyword1% AND 
 digest LIKE %keyword2% AND 
 digest LIKE %keyword3% ... 

Redirecting 404 error with .htaccess via 301 for SEO etc

I came up with the solution and posted it on my blog

http://web.archive.org/web/20130310123646/http://onlinemarketingexperts.com.au/2013/01/how-to-permanently-redirect-301-all-404-missing-pages-in-htaccess/

here is the htaccess code also

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule . / [L,R=301]

but I posted other solutions on my blog too, it depends what you need really

jQuery change URL of form submit

Try using this:

$(".move_to").on("click", function(e){
    e.preventDefault();
    $('#contactsForm').attr('action', "/test1").submit();
});

Moving the order in which you use .preventDefault() might fix your issue. You also didn't use function(e) so e.preventDefault(); wasn't working.

Here it is working: http://jsfiddle.net/TfTwe/1/ - first of all, click the 'Check action attribute.' link. You'll get an alert saying undefined. Then click 'Set action attribute.' and click 'Check action attribute.' again. You'll see that the form's action attribute has been correctly set to /test1.

How do I check to see if my array includes an object?

#include? should work, it works for general objects, not only strings. Your problem in example code is this test:

unless @suggested_horses.exists?(horse.id)
  @suggested_horses<< horse
end

(even assuming using #include?). You try to search for specific object, not for id. So it should be like this:

unless @suggested_horses.include?(horse)
  @suggested_horses << horse
end

ActiveRecord has redefined comparision operator for objects to take a look only for its state (new/created) and id

SHOW PROCESSLIST in MySQL command: sleep

I found this answer here: https://dba.stackexchange.com/questions/1558. In short using the following (or within my.cnf) will remove the timeout issue.

SET GLOBAL interactive_timeout = 180; SET GLOBAL wait_timeout = 180;

This allows the connections to end if they remain in a sleep State for 3 minutes (or whatever you define).

A TypeScript GUID class?

I found this https://typescriptbcl.codeplex.com/SourceControl/latest

here is the Guid version they have in case the link does not work later.

module System {
    export class Guid {
        constructor (public guid: string) {
            this._guid = guid;
        }

        private _guid: string;

        public ToString(): string {
            return this.guid;
        }

        // Static member
        static MakeNew(): Guid {
            var result: string;
            var i: string;
            var j: number;

            result = "";
            for (j = 0; j < 32; j++) {
                if (j == 8 || j == 12 || j == 16 || j == 20)
                    result = result + '-';
                i = Math.floor(Math.random() * 16).toString(16).toUpperCase();
                result = result + i;
            }
            return new Guid(result);
        }
    }
}

Difference between Width:100% and width:100vw?

Havengard's answer doesn't seem to be strictly true. I've found that vw fills the viewport width, but doesn't account for the scrollbars. So, if your content is taller than the viewport (so that your site has a vertical scrollbar), then using vw results in a small horizontal scrollbar. I had to switch out width: 100vw for width: 100% to get rid of the horizontal scrollbar.

Is there more to an interface than having the correct methods

Interfaces are a way to make your code more flexible. What you do is this:

Ibox myBox=new Rectangle();

Then, later, if you decide you want to use a different kind of box (maybe there's another library, with a better kind of box), you switch your code to:

Ibox myBox=new OtherKindOfBox();

Once you get used to it, you'll find it's a great (actually essential) way to work.

Another reason is, for example, if you want to create a list of boxes and perform some operation on each one, but you want the list to contain different kinds of boxes. On each box you could do:

myBox.close()

(assuming IBox has a close() method) even though the actual class of myBox changes depending on which box you're at in the iteration.

Displaying a Table in Django from Database

If you want to table do following steps:-

views.py:

def view_info(request):
    objs=Model_name.objects.all()
    ............
    return render(request,'template_name',{'objs':obj})

.html page

 {% for item in objs %}
    <tr> 
         <td>{{ item.field1 }}</td>
         <td>{{ item.field2 }}</td>
         <td>{{ item.field3 }}</td>
         <td>{{ item.field4 }}</td>
    </tr>
       {% endfor %}

VS2010 How to include files in project, to copy them to build output directory automatically during build or publish

I only have the need to push files during a build, so I just added a Post-build Event Command Line entry like this:

Copy /Y "$(SolutionDir)Third Party\SomeLibrary\*" "$(TargetDir)"

You can set this by right-clicking your Project in the Solution Explorer, then Properties > Build Events

Python Pylab scatter plot error bars (the error on each point is unique)

>>> import matplotlib.pyplot as plt
>>> a = [1,3,5,7]
>>> b = [11,-2,4,19]
>>> plt.pyplot.scatter(a,b)
>>> plt.scatter(a,b)
<matplotlib.collections.PathCollection object at 0x00000000057E2CF8>
>>> plt.show()
>>> c = [1,3,2,1]
>>> plt.errorbar(a,b,yerr=c, linestyle="None")
<Container object of 3 artists>
>>> plt.show()

where a is your x data b is your y data c is your y error if any

note that c is the error in each direction already

Get Public URL for File - Google Cloud Storage - App Engine (Python)

You need to use get_serving_url from the Images API. As that page explains, you need to call create_gs_key() first to get the key to pass to the Images API.

JavaScript moving element in the DOM

jQuery.fn.swap = function(b){ 
    b = jQuery(b)[0]; 
    var a = this[0]; 
    var t = a.parentNode.insertBefore(document.createTextNode(''), a); 
    b.parentNode.insertBefore(a, b); 
    t.parentNode.insertBefore(b, t); 
    t.parentNode.removeChild(t); 
    return this; 
};

and use it like this:

$('#div1').swap('#div2');

if you don't want to use jQuery you could easily adapt the function.

Shell script to check if file exists

for entry in "/home/loc/etc/"/*
do

   if [ -s /home/loc/etc/$entry ]
   then
       echo "$entry File is available"
   else
       echo "$entry File is not available"
fi
done

Hope it helps

CORS: credentials mode is 'include'

Customizing CORS for Angular 5 and Spring Security (Cookie base solution)

On the Angular side required adding option flag withCredentials: true for Cookie transport:

constructor(public http: HttpClient) {
}

public get(url: string = ''): Observable<any> {
    return this.http.get(url, { withCredentials: true });
}

On Java server-side required adding CorsConfigurationSource for configuration CORS policy:

@Configuration
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Bean
    CorsConfigurationSource corsConfigurationSource() {
        CorsConfiguration configuration = new CorsConfiguration();
        // This Origin header you can see that in Network tab
        configuration.setAllowedOrigins(Arrays.asList("http:/url_1", "http:/url_2")); 
        configuration.setAllowedMethods(Arrays.asList("GET","POST"));
        configuration.setAllowedHeaders(Arrays.asList("content-type"));
        configuration.setAllowCredentials(true);
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", configuration);
        return source;
    }

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.cors().and()...
    }
}

Method configure(HttpSecurity http) by default will use corsConfigurationSource for http.cors()

The conversion of the varchar value overflowed an int column

Just make rdg2.nPhoneNumber varchar everywhere instead of int !

How do I get the current time zone of MySQL?

The query below returns the timezone of the current session.

select timediff(now(),convert_tz(now(),@@session.time_zone,'+00:00'));

Move to another EditText when Soft Keyboard Next is clicked on Android

Try Using android:imeOptions="actionNext" tag for every editText in the View it will automatically focus to the next edittext when you click on Next of the softKeyboard.

MySQL SELECT only not null values

Yes use NOT NULL in your query like this below.

SELECT * 
FROM table
WHERE col IS NOT NULL;

Current time formatting with Javascript

2.39KB minified. One file. https://github.com/rhroyston/clock-js

Current Time is

var str = clock.month;
var m = str.charAt(0).toUpperCase() + str.slice(1,3); //gets you abbreviated month
clock.weekday + ' ' + clock.time + ' ' + clock.day + ' ' + m + ' ' + clock.year; //"tuesday 5:50 PM 3 May 2016"

Lowercase and Uppercase with jQuery

I think you want to lowercase the checked value? Try:

var jIsHasKids = $('#chkIsHasKids:checked').val().toLowerCase();

or you want to check it, then get its value as lowercase:

var jIsHasKids = $('#chkIsHasKids').attr("checked", true).val().toLowerCase();

Return value of x = os.system(..)

os.system('command') returns a 16 bit number, which first 8 bits from left(lsb) talks about signal used by os to close the command, Next 8 bits talks about return code of command.

Refer my answer for more detail in What is the return value of os.system() in Python?

How to get the indexpath.row when an element is activated?

In my case i have multiple sections and both the section and row index is vital, so in such a case i just created a property on UIButton which i set the cell indexPath like so:

fileprivate struct AssociatedKeys {
    static var index = 0
}

extension UIButton {

    var indexPath: IndexPath? {
        get {
            return objc_getAssociatedObject(self, &AssociatedKeys.index) as? IndexPath
        }
        set {
            objc_setAssociatedObject(self, &AssociatedKeys.index, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }
}

Then set the property in cellForRowAt like this :

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCellWithIdentifier("Cell") as! Cell
    cell.button.indexPath = indexPath
}

Then in the handleTapAction you can get the indexPath like this :

@objc func handleTapAction(_ sender: UIButton) {
    self.selectedIndex = sender.indexPath

}

How to show PIL Image in ipython notebook

Based on other answers and my tries, best experience would be first installing, pillow and scipy, then using the following starting code on your jupyter notebook:

%matplotlib inline
from matplotlib.pyplot import imshow
from scipy.misc import imread

imshow(imread('image.jpg', 1))

Moq, SetupGet, Mocking a property

But while mocking read-only properties means properties with getter method only you should declare it as virtual otherwise System.NotSupportedException will be thrown because it is only supported in VB as moq internally override and create proxy when we mock anything.

Session state can only be used when enableSessionState is set to true either in a configuration

also if you are running SharePoint and encounter this error, don't forget to run

Enable-SPSessionStateService -DefaultProvision

or you will continue to receive the above error message.

How to enter a multi-line command

Just use ` character to separate command on multiline

launch sms application with an intent

Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_DEFAULT);
intent.setType("vnd.android-dir/mms-sms");
startActivity(intent);

That's all you need.

How to remove leading whitespace from each line in a file

Use:

sed -e **'s/^[ \t]*//'**  name_of_file_from_which_you_want_to_remove_space > 'name _file_where_you_want_to_store_output'

For example:

sed -e 's/^[ \t]*//'  file1.txt > output.txt

Note:

s/: Substitute command ~ replacement for pattern (^[ \t]*) on each addressed line

^[ \t]*: Search pattern ( ^ – start of the line; [ \t]* match one or more blank spaces including tab)

//: Replace (delete) all matched patterns

gcc: undefined reference to

Are you mixing C and C++? One issue that can occur is that the declarations in the .h file for a .c file need to be surrounded by:

#if defined(__cplusplus)
  extern "C" {                 // Make sure we have C-declarations in C++ programs
#endif

and:

#if defined(__cplusplus)
  }
#endif

Note: if unable / unwilling to modify the .h file(s) in question, you can surround their inclusion with extern "C":

extern "C" {
#include <abc.h>
} //extern

How can I put the current running linux process in background?

Suspend the process with CTRL+Z then use the command bg to resume it in background. For example:

sleep 60
^Z  #Suspend character shown after hitting CTRL+Z
[1]+  Stopped  sleep 60  #Message showing stopped process info
bg  #Resume current job (last job stopped)

More about job control and bg usage in bash manual page:

JOB CONTROL
Typing the suspend character (typically ^Z, Control-Z) while a process is running causes that process to be stopped and returns control to bash. [...] The user may then manipulate the state of this job, using the bg command to continue it in the background, [...]. A ^Z takes effect immediately, and has the additional side effect of causing pending output and typeahead to be discarded.

bg [jobspec ...]
Resume each suspended job jobspec in the background, as if it had been started with &. If jobspec is not present, the shell's notion of the current job is used.

EDIT

To start a process where you can even kill the terminal and it still carries on running

nohup [command] [-args] > [filename] 2>&1 &

e.g.

nohup /home/edheal/myprog -arg1 -arg2 > /home/edheal/output.txt 2>&1 &

To just ignore the output (not very wise) change the filename to /dev/null

To get the error message set to a different file change the &1 to a filename.

In addition: You can use the jobs command to see an indexed list of those backgrounded processes. And you can kill a backgrounded process by running kill %1 or kill %2 with the number being the index of the process.

Get rid of "The value for annotation attribute must be a constant expression" message

This is what a constant expression in Java looks like:

package com.mycompany.mypackage;

public class MyLinks {
  // constant expression
  public static final String GUESTBOOK_URL = "/guestbook";
}

You can use it with annotations as following:

import com.mycompany.mypackage.MyLinks;

@WebServlet(urlPatterns = {MyLinks.GUESTBOOK_URL})
public class GuestbookServlet extends HttpServlet {
  // ...
}

How do you completely remove Ionic and Cordova installation from mac?

You can use following command if you uninstall globally

npm uninstall -g cordova ionic

option g for global

if you want to uninstall from he drive then you can use following command

npm uninstall cordova ionic

What do the return values of Comparable.compareTo mean in Java?

Answer in short: (search your situation)

  • 1.compareTo(0) (return: 1)
  • 1.compareTo(1) (return: 0)
  • 0.comapreTo(1) (return: -1)

How do I remove repeated elements from ArrayList?

Suppose we have a list of String like:

List<String> strList = new ArrayList<>(5);
// insert up to five items to list.        

Then we can remove duplicate elements in multiple ways.

Prior to Java 8

List<String> deDupStringList = new ArrayList<>(new HashSet<>(strList));

Note: If we want to maintain the insertion order then we need to use LinkedHashSet in place of HashSet

Using Guava

List<String> deDupStringList2 = Lists.newArrayList(Sets.newHashSet(strList));

Using Java 8

List<String> deDupStringList3 = strList.stream().distinct().collect(Collectors.toList());

Note: In case we want to collect the result in a specific list implementation e.g. LinkedList then we can modify the above example as:

List<String> deDupStringList3 = strList.stream().distinct()
                 .collect(Collectors.toCollection(LinkedList::new));

We can use parallelStream also in the above code but it may not give expected performace benefits. Check this question for more.

Using Server.MapPath() inside a static field in ASP.NET MVC

I think you can try this for calling in from a class

 System.Web.HttpContext.Current.Server.MapPath("~/SignatureImages/");

*----------------Sorry I oversight, for static function already answered the question by adrift*

System.Web.Hosting.HostingEnvironment.MapPath("~/SignatureImages/");

Update

I got exception while using System.Web.Hosting.HostingEnvironment.MapPath("~/SignatureImages/");

Ex details : System.ArgumentException: The relative virtual path 'SignatureImages' is not allowed here. at System.Web.VirtualPath.FailIfRelativePath()

Solution (tested in static webmethod)

System.Web.HttpContext.Current.Server.MapPath("~/SignatureImages/"); Worked

How do I add slashes to a string in Javascript?

Following JavaScript function handles ', ", \b, \t, \n, \f or \r equivalent of php function addslashes().

function addslashes(string) {
    return string.replace(/\\/g, '\\\\').
        replace(/\u0008/g, '\\b').
        replace(/\t/g, '\\t').
        replace(/\n/g, '\\n').
        replace(/\f/g, '\\f').
        replace(/\r/g, '\\r').
        replace(/'/g, '\\\'').
        replace(/"/g, '\\"');
}

How do I prevent Conda from activating the base environment by default?

So in the end I found that if I commented out the Conda initialisation block like so:

# >>> conda initialize >>>
# !! Contents within this block are managed by 'conda init' !!
# __conda_setup="$('/Users/geoff/anaconda2/bin/conda' 'shell.bash' 'hook' 2> /dev/null)"
# if [ $? -eq 0 ]; then
    # eval "$__conda_setup"
# else
if [ -f "/Users/geoff/anaconda2/etc/profile.d/conda.sh" ]; then
    . "/Users/geoff/anaconda2/etc/profile.d/conda.sh"
else
    export PATH="/Users/geoff/anaconda2/bin:$PATH"
fi
# fi
# unset __conda_setup
# <<< conda initialize <<<

It works exactly how I want. That is, Conda is available to activate an environment if I want, but doesn't activate by default.

How to clear cache of Eclipse Indigo

I think you can find the answer you want in these two posts. They are mentioning Flash Builder, but essentially, the talk is about its Eclipse base.

Clear improperly cached compile errors in FlexBuilder: http://blog.aherrman.com/2010/05/clear-improperly-cached-compile-errors.html

How to fix Flash Builder broken workspace: http://va.lent.in/how-to-fix-flash-builder-broken-workspace/

How to get Month Name from Calendar?

Joda-Time

How about using Joda-Time. It's a far better date-time API to work with (And January means january here. It's not like Calendar, which uses 0-based index for months).

You can use AbstractDateTime#toString( pattern ) method to format the date in specified format:

DateTime date = DateTime.now();
String month = date.toString("MMM");

Month Name From Number

If you want month name for a particular month number, you can do it like this:

int month = 3;
String monthName = DateTime.now().withMonthOfYear(month).toString("MMM");

Localize

The above approach uses your JVM’s current default Locale for the language of the month name. You want to specify a Locale object instead.

String month = date.toString( "MMM", Locale.CANADA_FRENCH );

Concatenating Matrices in R

Sounds like you're looking for rbind:

> a<-matrix(nrow=10,ncol=5)
> b<-matrix(nrow=20,ncol=5)
> dim(rbind(a,b))
[1] 30  5

Similarly, cbind stacks the matrices horizontally.

I am not entirely sure what you mean by the last question ("Can I do this for matrices of different rows and columns.?")

How to create a simple checkbox in iOS?

Yeah, no checkbox for you in iOS (-:

Here, this is what I did to create a checkbox:

UIButton *checkbox;
BOOL checkBoxSelected;
checkbox = [[UIButton alloc] initWithFrame:CGRectMake(x,y,20,20)];
// 20x20 is the size of the checkbox that you want
// create 2 images sizes 20x20 , one empty square and
// another of the same square with the checkmark in it
// Create 2 UIImages with these new images, then:

[checkbox setBackgroundImage:[UIImage imageNamed:@"notselectedcheckbox.png"]
                    forState:UIControlStateNormal];
[checkbox setBackgroundImage:[UIImage imageNamed:@"selectedcheckbox.png"]
                    forState:UIControlStateSelected];
[checkbox setBackgroundImage:[UIImage imageNamed:@"selectedcheckbox.png"]
                    forState:UIControlStateHighlighted];
checkbox.adjustsImageWhenHighlighted=YES;
[checkbox addTarget:(nullable id) action:(nonnull SEL) forControlEvents:(UIControlEvents)];
[self.view addSubview:checkbox];

Now in the target method do the following:

-(void)checkboxSelected:(id)sender
{
    checkBoxSelected = !checkBoxSelected; /* Toggle */
    [checkbox setSelected:checkBoxSelected];
}

That's it!

Bundler: Command not found

Step 1:Make sure you are on path actual workspace.For example, workspace/blog $: Step2:Enter the command: gem install bundler. Step 3: You should be all set to bundle install or bundle update by now

How to force reloading a page when using browser back button?

Currently this is the most up to date way reload page if the user clicks the back button.

const [entry] = performance.getEntriesByType("navigation");

// Show it in a nice table in the developer console
console.table(entry.toJSON());

if (entry["type"] === "back_forward")
    location.reload();

See here for source

ActionController::InvalidAuthenticityToken

For me the cause of this issue under Rails 4 was a missing,

<%= csrf_meta_tags %>

Line in my main application layout. I had accidently deleted it when I rewrote my layout.

If this isn't in the main layout you will need it in any page that you want a CSRF token on.

What can I use for good quality code coverage for C#/.NET?

TestCocoon is also pretty nice. It is in active development and has a user community:

  • Open source (GPL 3)
  • Supports C/C++/C# cross platform (Linux, Windows, and Mac)
  • CoverageScanner - Instrumentation during the Generation
  • CoverageBrowser - View, Analysis and Management of Code Coverage Result

However, TestCocoon is no longer developed and its creators are now producing a commercial software for C/C++.

How do you change the datatype of a column in SQL Server?

ALTER TABLE [dbo].[TableName]
ALTER COLUMN ColumnName VARCHAR(Max) NULL

What are the JavaScript KeyCodes?

One possible answer will be given when you run this snippet.

_x000D_
_x000D_
document.write('<table>')_x000D_
for (var i = 0; i < 250; i++) {_x000D_
  document.write('<tr><td>' + i + '</td><td>' + String.fromCharCode(i) + '</td></tr>')_x000D_
}_x000D_
document.write('</table>')
_x000D_
td {_x000D_
  border: solid 1px;_x000D_
  padding: 1px 12px;_x000D_
  text-align: right;_x000D_
}_x000D_
table {_x000D_
  border-collapse: collapse;_x000D_
}_x000D_
* {_x000D_
  font-family: monospace;_x000D_
  font-size: 1.1em;_x000D_
}
_x000D_
_x000D_
_x000D_

Maintain model of scope when changing between views in AngularJS

I had the same problem, This is what I did: I have a SPA with multiple views in the same page (without ajax), so this is the code of the module:

var app = angular.module('otisApp', ['chieffancypants.loadingBar', 'ngRoute']);

app.config(['$routeProvider', function($routeProvider){
    $routeProvider.when('/:page', {
        templateUrl: function(page){return page.page + '.html';},
        controller:'otisCtrl'
    })
    .otherwise({redirectTo:'/otis'});
}]);

I have only one controller for all views, but, the problem is the same as the question, the controller always refresh data, in order to avoid this behavior I did what people suggest above and I created a service for that purpose, then pass it to the controller as follows:

app.factory('otisService', function($http){
    var service = {            
        answers:[],
        ...

    }        
    return service;
});

app.controller('otisCtrl', ['$scope', '$window', 'otisService', '$routeParams',  
function($scope, $window, otisService, $routeParams){        
    $scope.message = "Hello from page: " + $routeParams.page;
    $scope.update = function(answer){
        otisService.answers.push(answers);
    };
    ...
}]);

Now I can call the update function from any of my views, pass values and update my model, I haven't no needed to use html5 apis for persistence data (this is in my case, maybe in other cases would be necessary to use html5 apis like localstorage and other stuff).

Center image horizontally within a div

To center an image horizontally, this works:

<p style="text-align:center"><img src=""></p>

How to get File Created Date and Modified Date

You could use below code:

DateTime creation = File.GetCreationTime(@"C:\test.txt");
DateTime modification = File.GetLastWriteTime(@"C:\test.txt");

How to display Woocommerce Category image?

From the WooCommerce page:

// WooCommerce – display category image on category archive

add_action( 'woocommerce_archive_description', 'woocommerce_category_image', 2 );
function woocommerce_category_image() {
    if ( is_product_category() ){
      global $wp_query;
      $cat = $wp_query->get_queried_object();
      $thumbnail_id = get_woocommerce_term_meta( $cat->term_id, 'thumbnail_id', true );
      $image = wp_get_attachment_url( $thumbnail_id );
      if ( $image ) {
          echo '<img src="' . $image . '" alt="" />';
      }
  }
}

String "true" and "false" to boolean

Security Notice

Note that this answer in its bare form is only appropriate for the other use case listed below rather than the one in the question. While mostly fixed, there have been numerous YAML related security vulnerabilities which were caused by loading user input as YAML.


A trick I use for converting strings to bools is YAML.load, e.g.:

YAML.load(var) # -> true/false if it's one of the below

YAML bool accepts quite a lot of truthy/falsy strings:

y|Y|yes|Yes|YES|n|N|no|No|NO
|true|True|TRUE|false|False|FALSE
|on|On|ON|off|Off|OFF

Another use case

Assume that you have a piece of config code like this:

config.etc.something = ENV['ETC_SOMETHING']

And in command line:

$ export ETC_SOMETHING=false

Now since ENV vars are strings once inside code, config.etc.something's value would be the string "false" and it would incorrectly evaluate to true. But if you do like this:

config.etc.something = YAML.load(ENV['ETC_SOMETHING'])

it would be all okay. This is compatible with loading configs from .yml files as well.

How can I get the current time in C#?

DateTime.Now.ToString("HH:mm:ss tt");

this gives it to you as a string.

Show/Hide Table Rows using Javascript classes

event.preventDefault()

Doesn't work in all browsers. Instead you could return false in OnClick event.

onClick="toggle_it('tr1');toggle_it('tr2'); return false;">

Not sure if this is the best way, but I tested in IE, FF and Chrome and its working fine.

How do I set a path in Visual Studio?

You have a couple of options:

  • You can add the path to the DLLs to the Executable files settings under Tools > Options > Projects and Solutions > VC++ Directories (but only for building, for executing or debugging here)
  • You can add them in your global PATH environment variable
  • You can start Visual Studio using a batch file as I described here and manipulate the path in that one
  • You can copy the DLLs into the executable file's directory :-)

Changing the action of a form with JavaScript/jQuery

You can actually just use

$("#form").attr("target", "NewAction");

As far as I know, this will NOT fail silently.

If the page is opening in a new target, you may need to make sure the URL is unique each time because Webkit (chrome/safari) will cache the fact you have visited that URL and won't perform the post.

For example

$("form").attr("action", "/Pages/GeneratePreview?" + new Date().getMilliseconds());

What is the common header format of Python files?

I strongly favour minimal file headers, by which I mean just:

  • The hashbang (#! line) if this is an executable script
  • Module docstring
  • Imports, grouped in the standard way, eg:
  import os    # standard library
  import sys

  import requests  # 3rd party packages

  from mypackage import (  # local source
      mymodule,
      myothermodule,
  )

ie. three groups of imports, with a single blank line between them. Within each group, imports are sorted. The final group, imports from local source, can either be absolute imports as shown, or explicit relative imports.

Everything else is a waste of time, visual space, and is actively misleading.

If you have legal disclaimers or licencing info, it goes into a separate file. It does not need to infect every source code file. Your copyright should be part of this. People should be able to find it in your LICENSE file, not random source code.

Metadata such as authorship and dates is already maintained by your source control. There is no need to add a less-detailed, erroneous, and out-of-date version of the same info in the file itself.

I don't believe there is any other data that everyone needs to put into all their source files. You may have some particular requirement to do so, but such things apply, by definition, only to you. They have no place in “general headers recommended for everyone”.

Eclipse change project files location

Much more simple: Right click -> Refactor -> Move.

Converting a string to JSON object

convert the string to HashMap using Object Mapper ...

new ObjectMapper().readValue(string, Map.class);

Internally Map will behave as JSON Object

.map() a Javascript ES6 Map?

Actually you can still have a Map with the original keys after converting to array with Array.from. That's possible by returning an array, where the first item is the key, and the second is the transformed value.

const originalMap = new Map([
  ["thing1", 1], ["thing2", 2], ["thing3", 3]
]);

const arrayMap = Array.from(originalMap, ([key, value]) => {
    return [key, value + 1]; // return an array
});

const alteredMap = new Map(arrayMap);

console.log(originalMap); // Map { 'thing1' => 1, 'thing2' => 2, 'thing3' => 3 }
console.log(alteredMap);  // Map { 'thing1' => 2, 'thing2' => 3, 'thing3' => 4 }

If you don't return that key as the first array item, you loose your Map keys.

How do I find the stack trace in Visual Studio?

Consider this as the current update (Windows 10 (Version 1803) and Visual Studio 2017): I was unable to view the stack trace window and did find an option/menu item to view it. On investigating further, it seems this feature is not available on Windows 10. For further information please refer:

https://docs.microsoft.com/en-us/windows-hardware/drivers/debugger/viewing-the-call-stack-in-visual-studio

Copied from the above link: "This feature is not available in Windows 10, version 1507 and later versions of the WDK."

How to fix '.' is not an internal or external command error

I got exactly the same error in Windows 8 while trying to export decision tree digraph using tree.export_graphviz! Then I installed GraphViz from this link. And then I followed the below steps which resolved my issue:

  • Right click on My PC >> click on "Change Settings" under "Computer name, domain, and workgroup settings"
  • It will open the System Properties window; Goto 'Advanced' tab >> click on 'Environment Variables' >> Under "System Variables" >> select 'Path' and click on 'Edit' >> In 'Variable Value' field, put a semicolon (;) at the end of existing value and then include the path of its installation folder (e.g. ;C:\Program Files (x86)\Graphviz2.38\bin) >> Click on 'Ok' >> 'Ok' >> 'Ok'
  • Restart your PC as environment variables are changed

How to convert a column of DataTable to a List

var list = dataTable.Rows.OfType<DataRow>()
    .Select(dr => dr.Field<string>(columnName)).ToList();

[Edit: Add a reference to System.Data.DataSetExtensions to your project if this does not compile]

jQuery UI autocomplete with JSON

I understand that its been answered already. but I hope this will help someone in future and saves so much time and pain.

complete code is below: This one I did for a textbox to make it Autocomplete in CiviCRM. Hope it helps someone

CRM.$( 'input[id^=custom_78]' ).autocomplete({
            autoFill: true,
            select: function (event, ui) {
                    var label = ui.item.label;
                    var value = ui.item.value;
                    // Update subject field to add book year and book product
                    var book_year_value = CRM.$('select[id^=custom_77]  option:selected').text().replace('Book Year ','');
                    //book_year_value.replace('Book Year ','');
                    var subject_value = book_year_value + '/' + ui.item.label;
                    CRM.$('#subject').val(subject_value);
                    CRM.$( 'input[name=product_select_id]' ).val(ui.item.value);
                    CRM.$('input[id^=custom_78]').val(ui.item.label);
                    return false;
            },
            source: function(request, response) {
                CRM.$.ajax({
                    url: productUrl,
                        data: {
                                        'subCategory' : cj('select[id^=custom_77]').val(),
                                        's': request.term,
                                    },
                    beforeSend: function( xhr ) {
                        xhr.overrideMimeType( "text/plain; charset=x-user-defined" );
                    },

                    success: function(result){
                                result = jQuery.parseJSON( result);
                                //console.log(result);
                                response(CRM.$.map(result, function (val,key) {
                                                         //console.log(key);
                                                         //console.log(val);
                                                         return {
                                                                 label: val,
                                                                 value: key
                                                         };
                                                 }));
                    }
                })
                .done(function( data ) {
                    if ( console && console.log ) {
                     // console.log( "Sample of dataas:", data.slice( 0, 100 ) );
                    }
                });
            }
  });

PHP code on how I'm returning data to this jquery ajax call in autocomplete:

/**
 * This class contains all product related functions that are called using AJAX (jQuery)
 */
class CRM_Civicrmactivitiesproductlink_Page_AJAX {
  static function getProductList() {
        $name   = CRM_Utils_Array::value( 's', $_GET );
    $name   = CRM_Utils_Type::escape( $name, 'String' );
    $limit  = '10';

        $strSearch = "description LIKE '%$name%'";

        $subCategory   = CRM_Utils_Array::value( 'subCategory', $_GET );
    $subCategory   = CRM_Utils_Type::escape( $subCategory, 'String' );

        if (!empty($subCategory))
        {
                $strSearch .= " AND sub_category = ".$subCategory;
        }

        $query = "SELECT id , description as data FROM abc_books WHERE $strSearch";
        $resultArray = array();
        $dao = CRM_Core_DAO::executeQuery( $query );
        while ( $dao->fetch( ) ) {
            $resultArray[$dao->id] = $dao->data;//creating the array to send id as key and data as value
        }
        echo json_encode($resultArray);
    CRM_Utils_System::civiExit();
  }
}

Dictionary of dictionaries in Python?

dictionary's setdefault is a good way to update an existing dict entry if it's there, or create a new one if it's not all in one go:

Looping style:

# This is our sample data
data = [("Milter", "Miller", 4), ("Milter", "Miler", 4), ("Milter", "Malter", 2)]

# dictionary we want for the result
dictionary = {}

# loop that makes it work
for realName, falseName, position in data:
    dictionary.setdefault(realName, {})[falseName] = position

dictionary now equals:

{'Milter': {'Malter': 2, 'Miler': 4, 'Miller': 4}}

PHP Get Site URL Protocol - http vs https

I know I'm a bit late to this party, but if you much prefer not using $_SERVER as it's strongly discouraged, and even deactivated on some PHP frameworks; and you have an apache web server, you can use it's native command thusly: -

$protocol = apache_getenv('HTTPS') ? 'https:' : 'http:';

In git, what is the difference between merge --squash and rebase?

Merge commits: retains all of the commits in your branch and interleaves them with commits on the base branchenter image description here

Merge Squash: retains the changes but omits the individual commits from history enter image description here

Rebase: This moves the entire feature branch to begin on the tip of the master branch, effectively incorporating all of the new commits in master

enter image description here

More on here

Tensorflow import error: No module named 'tensorflow'

In Windows 64, if you did this sequence correctly:

Anaconda prompt:

conda create -n tensorflow python=3.5
activate tensorflow
pip install --ignore-installed --upgrade tensorflow

Be sure you still are in tensorflow environment. The best way to make Spyder recognize your tensorflow environment is to do this:

conda install spyder

This will install a new instance of Spyder inside Tensorflow environment. Then you must install scipy, matplotlib, pandas, sklearn and other libraries. Also works for OpenCV.

Always prefer to install these libraries with "conda install" instead of "pip".

iFrame src change event detection?

The iframe always keeps the parent page, you should use this to detect in which page you are in the iframe:

Html code:

<iframe id="iframe" frameborder="0" scrolling="no" onload="resizeIframe(this)" width="100%" src="www.google.com"></iframe>

Js:

    function resizeIframe(obj) {
        alert(obj.contentWindow.location.pathname);
    }

pandas read_csv index_col=None not working with delimiters at the end of each line

Re: craigts's response, for anyone having trouble with using either False or None parameters for index_col, such as in cases where you're trying to get rid of a range index, you can instead use an integer to specify the column you want to use as the index. For example:

df = pd.read_csv('file.csv', index_col=0)

The above will set the first column as the index (and not add a range index in my "common case").

Update

Given the popularity of this answer, I thought i'd add some context/ a demo:

# Setting up the dummy data
In [1]: df = pd.DataFrame({"A":[1, 2, 3], "B":[4, 5, 6]})

In [2]: df
Out[2]:
   A  B
0  1  4
1  2  5
2  3  6

In [3]: df.to_csv('file.csv', index=None)
File[3]:
A  B
1  4
2  5
3  6

Reading without index_col or with None/False will all result in a range index:

In [4]: pd.read_csv('file.csv')
Out[4]:
   A  B
0  1  4
1  2  5
2  3  6

# Note that this is the default behavior, so the same as In [4]
In [5]: pd.read_csv('file.csv', index_col=None)
Out[5]:
   A  B
0  1  4
1  2  5
2  3  6

In [6]: pd.read_csv('file.csv', index_col=False)
Out[6]:
   A  B
0  1  4
1  2  5
2  3  6

However, if we specify that "A" (the 0th column) is actually the index, we can avoid the range index:

In [7]: pd.read_csv('file.csv', index_col=0)
Out[7]:
   B
A
1  4
2  5
3  6

Install specific version using laravel installer

use laravel new blog --5.1
make sure you must have laravel installer 1.3.4 version.

DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss") is returning AM time instead of PM time?

Use HH for 24 hour hours format:

DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")

Or the tt format specifier for the AM/PM part:

DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss tt")

Take a look at the custom Date and Time format strings documentation.

HTML: How to create a DIV with only vertical scroll-bars for long paragraphs?

to hide the horizontal scrollbars, you can set overflow-x to hidden, like this:

overflow-x: hidden;

How to read pickle file?

The following is an example of how you might write and read a pickle file. Note that if you keep appending pickle data to the file, you will need to continue reading from the file until you find what you want or an exception is generated by reaching the end of the file. That is what the last function does.

import os
import pickle


PICKLE_FILE = 'pickle.dat'


def main():
    # append data to the pickle file
    add_to_pickle(PICKLE_FILE, 123)
    add_to_pickle(PICKLE_FILE, 'Hello')
    add_to_pickle(PICKLE_FILE, None)
    add_to_pickle(PICKLE_FILE, b'World')
    add_to_pickle(PICKLE_FILE, 456.789)
    # load & show all stored objects
    for item in read_from_pickle(PICKLE_FILE):
        print(repr(item))
    os.remove(PICKLE_FILE)


def add_to_pickle(path, item):
    with open(path, 'ab') as file:
        pickle.dump(item, file, pickle.HIGHEST_PROTOCOL)


def read_from_pickle(path):
    with open(path, 'rb') as file:
        try:
            while True:
                yield pickle.load(file)
        except EOFError:
            pass


if __name__ == '__main__':
    main()

maven "cannot find symbol" message unhelpful

Generally, this error will appear when your compile code's version is different from your written code's. For example, write code that rely on xxx-1.0.0.jar that one class has method A, but the method changed to B in xxx-1.1.0.jar. If you compile code with xxx-1.1.0.jar, you will see the error.

How to download Javadoc to read offline?

JAVA Fax Api documentation

You could download the mac 2.2 preview release from here and unzip it.

http://www.oracle.com/technetwork/java/javafx/downloads/devpreview-1429449.html

The javadoc won't quite match 2.1, but it will be close and if you use the preview instead, it will match exactly.

I think this would help you :)

How to conclude your merge of a file?

I had the same error and i did followed article found on google solves my issue. You have not concluded your merge

How to print a single backslash?

You should escape it with another backslash \:

print('\\')

What is a PDB file?

I had originally asked myself the question "Do I need a PDB file deployed to my customer's machine?", and after reading this post, decided to exclude the file.

Everything worked fine, until today, when I was trying to figure out why a message box containing an Exception.StackTrace was missing the file and line number information - necessary for troubleshooting the exception. I re-read this post and found the key nugget of information: that although the PDB is not necessary for the app to run, it is necessary for the file and line numbers to be present in the StackTrace string. I included the PDB file in the executable folder and now all is fine.

Pandas get the most frequent values of a column

Not Obvious, But Fast

f, u = pd.factorize(df.name.values)
counts = np.bincount(f)
u[counts == counts.max()]

array(['alex', 'helen'], dtype=object)

DataRow: Select cell value by a given column name

Be careful on datatype. If not match it will throw an error.

var fieldName = dataRow.Field<DataType>("fieldName");

Ansible: copy a directory content to another directory

This I found an ideal solution for copying file from Ansible server to remote.

copying yaml file

- hosts: localhost
  user: {{ user }}
  connection: ssh
  become: yes
  gather_facts: no
  tasks:
   - name: Creation of directory on remote server
     file:
       path: /var/lib/jenkins/.aws
       state: directory
       mode: 0755
     register: result
   - debug: 
       var: result

   - name: get file names to copy
     command: "find conf/.aws -type f"
     register: files_to_copy

   - name: copy files
     copy:
      src: "{{ item }}" 
      dest: "/var/lib/jenkins/.aws"
      owner: {{ user }}
      group: {{ group }}
      remote_src: True
      mode: 0644
     with_items:
      - "{{ files_to_copy.stdout_lines }}"

How to conditionally take action if FINDSTR fails to find a string

I presume you want to copy C:\OtherFolder\fileToCheck.bat to C:\MyFolder if the existing file in C:\MyFolder is either missing entirely, or if it is missing "stringToCheck".

FINDSTR sets ERRORLEVEL to 0 if the string is found, to 1 if it is not. It also sets errorlevel to 1 if the file is missing. It also prints out each line that matches. Since you are trying to use it as a condition, I presume you don't need or want to see any of the output. The 1st thing I would suggest is to redirect both the normal and error output to nul using >nul 2>&1.

Solution 1 (mostly the same as previous answers)

You can use IF ERRORRLEVEL N to check if the errorlevel is >= N. Or you can use IF NOT ERRORLEVEL N to check if errorlevel is < N. In your case you want the former.

findstr /c:"stringToCheck" "c:\MyFolder\fileToCheck.bat" >nul 2>&1
if errorlevel 1 xcopy "C:\OtherFolder\fileToCheck.bat" "c:\MyFolder"

Solution 2

You can test for a specific value of errorlevel by using %ERRORLEVEL%. You can probably check if the value is equal to 1, but it might be safer to check if the value is not equal to 0, since it is only set to 0 if the file exists and it contains the string.

findstr /c:"stringToCheck" "c:\MyFolder\fileToCheck.bat" >nul 2>&1
if not %errorlevel% == 0 xcopy "C:\OtherFolder\fileToCheck.bat" "c:\MyFolder"

or

findstr /c:"stringToCheck" "c:\MyFolder\fileToCheck.bat" >nul 2>&1
if %errorlevel% neq 0 xcopy "C:\OtherFolder\fileToCheck.bat" "c:\MyFolder"

Solution 3

There is a very compact syntax to conditionally execute a command based on the success or failure of the previous command: cmd1 && cmd2 || cmd3 which means execute cmd2 if cmd1 was successful (errorlevel=0), else execute cmd3 if cmd1 failed (errorlevel<>0). You can use && alone, or || alone. All the commands need to be on the same line. If you need to conditionally execute multiple commands you can use multiple lines by adding parentheses

cmd1 && (
   cmd2
   cmd3
) || (
   cmd4
   cmd5
)

So for your case, all you need is

findstr /c:"stringToCheck" "c:\MyFolder\fileToCheck.bat" >nul 2>&1 || xcopy "C:\OtherFolder\fileToCheck.bat" "c:\MyFolder"

But beware - the || will respond to the return code of the last command executed. In my earlier pseudo code the || will obviously fire if cmd1 fails, but it will also fire if cmd1 succeeds but then cmd3 fails.

So if your success block ends with a command that may fail, then you should append a harmless command that is guaranteed to succeed. I like to use (CALL ), which is harmless, and always succeeds. It also is handy that it sets the ERRORLEVEL to 0. There is a corollary (CALL) that always fails and sets ERRORLEVEL to 1.

Python locale error: unsupported locale setting

You error clearly says, you are trying to use locale something was not there.

>>> locale.setlocale(locale.LC_ALL, 'de_DE')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/locale.py", line 581, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting

locale.Error: unsupported locale setting

To check available setting, use locale -a

deb@deb-Latitude-E7470:/ambot$ locale -a
C
C.UTF-8
en_AG
en_AG.utf8
en_AU.utf8
en_BW.utf8
en_CA.utf8
en_DK.utf8
en_GB.utf8
en_HK.utf8
en_IE.utf8
en_IN
en_IN.utf8
en_NG
en_NG.utf8
en_NZ.utf8
en_PH.utf8
en_SG.utf8
en_US.utf8
en_ZA.utf8
en_ZM
en_ZM.utf8
en_ZW.utf8
POSIX

so you can use one among,

>>> locale.setlocale(locale.LC_ALL, 'en_AG.utf8')
'en_AG.utf8'
>>> 

for de_DE

This file can either be adjusted manually or updated using the tool, update-locale.

update-locale LANG=de_DE.UTF-8

C++ How do I convert a std::chrono::time_point to long and back

as a single line:

long value_ms = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::time_point_cast<std::chrono::milliseconds>(std::chrono::high_resolution_clock::now()).time_since_epoch()).count();

Extract time from date String

A very simple way is to use Formatter (see date time conversions) or more directly String.format as in

String.format("%tR", new Date())

Common xlabel/ylabel for matplotlib subplots

It will look better if you reserve space for the common labels by making invisible labels for the subplot in the bottom left corner. It is also good to pass in the fontsize from rcParams. This way, the common labels will change size with your rc setup, and the axes will also be adjusted to leave space for the common labels.

fig_size = [8, 6]
fig, ax = plt.subplots(5, 2, sharex=True, sharey=True, figsize=fig_size)
# Reserve space for axis labels
ax[-1, 0].set_xlabel('.', color=(0, 0, 0, 0))
ax[-1, 0].set_ylabel('.', color=(0, 0, 0, 0))
# Make common axis labels
fig.text(0.5, 0.04, 'common X', va='center', ha='center', fontsize=rcParams['axes.labelsize'])
fig.text(0.04, 0.5, 'common Y', va='center', ha='center', rotation='vertical', fontsize=rcParams['axes.labelsize'])

enter image description here enter image description here

Why does calling sumr on a stream with 50 tuples not complete

sumr is implemented in terms of foldRight:

 final def sumr(implicit A: Monoid[A]): A = F.foldRight(self, A.zero)(A.append) 

foldRight is not always tail recursive, so you can overflow the stack if the collection is too long. See Why foldRight and reduceRight are NOT tail recursive? for some more discussion of when this is or isn't true.

Update a table using JOIN in SQL Server?

You don't quite have SQL Server's proprietary UPDATE FROM syntax down. Also not sure why you needed to join on the CommonField and also filter on it afterward. Try this:

UPDATE t1
  SET t1.CalculatedColumn = t2.[Calculated Column]
  FROM dbo.Table1 AS t1
  INNER JOIN dbo.Table2 AS t2
  ON t1.CommonField = t2.[Common Field]
  WHERE t1.BatchNo = '110';

If you're doing something really silly - like constantly trying to set the value of one column to the aggregate of another column (which violates the principle of avoiding storing redundant data), you can use a CTE (common table expression) - see here and here for more details:

;WITH t2 AS
(
  SELECT [key], CalculatedColumn = SUM(some_column)
    FROM dbo.table2
    GROUP BY [key]
)
UPDATE t1
  SET t1.CalculatedColumn = t2.CalculatedColumn
  FROM dbo.table1 AS t1
  INNER JOIN t2
  ON t1.[key] = t2.[key];

The reason this is really silly, is that you're going to have to re-run this entire update every single time any row in table2 changes. A SUM is something you can always calculate at runtime and, in doing so, never have to worry that the result is stale.

Adding a SVN repository in Eclipse

Do you have any working repositories in this instance of eclipse?

I've had problems in the past with the default Subclipse subversion client on Windows, you need to make sure the native subversion client is installed and correctly configured (I've got TortoiseSVN to work in the past) if you want to use the default client adapter.

On a recent install I tried the "beta" drivers (I have Eclipse Ganymede and "SVNKit (Pure Java) SVNKit v1.2.0.4502") that you can optionally install with Subclipse and they worked pretty much straight out of the box, although a colleague found he had to go through a few hoops to make sure Eclipse installed them (and their dependancies) correctly.

Here are the packages that appear in "Help" -> "Software Updates" -> "Installed Software":

Subclipse                  1.4.0
Subversion Client Adapter  1.5.0.1
SVNKit Client Adapter      1.5.0.1
SVNKit Library             1.2.0.4502

These are probably a little out of date now, and the latest version will probably work better, but this is what I can see working right now.

How to view changes made to files on a certain revision in Subversion

The equivalent command in svn is:

svn log --diff -r revision

Install npm (Node.js Package Manager) on Windows (w/o using Node.js MSI)

To install npm on windows just unzip the npm archive where node is. See the docs for more detail.

npm is shipped with node, that is how you should install it. nvm is only for changing node versions and does not install npm. A cleaner way to use npm and nvm is to first install node as it is (with npm), then install the nvm package by npm install nvm

Why doesn't indexOf work on an array IE8?

Versions of IE before IE9 don't have an .indexOf() function for Array, to define the exact spec version, run this before trying to use it:

if (!Array.prototype.indexOf)
{
  Array.prototype.indexOf = function(elt /*, from*/)
  {
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++)
    {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}

This is the version from MDN, used in Firefox/SpiderMonkey. In other cases such as IE, it'll add .indexOf() in the case it's missing... basically IE8 or below at this point.

Creating threads - Task.Factory.StartNew vs new Thread()

Your first block of code tells CLR to create a Thread (say. T) for you which is can be run as background (use thread pool threads when scheduling T ). In concise, you explicitly ask CLR to create a thread for you to do something and call Start() method on thread to start.

Your second block of code does the same but delegate (implicitly handover) the responsibility of creating thread (background- which again run in thread pool) and the starting thread through StartNew method in the Task Factory implementation.

This is a quick difference between given code blocks. Having said that, there are few detailed difference which you can google or see other answers from my fellow contributors.

Error when trying to access XAMPP from a network

In your xampppath\apache\conf\extra open file httpd-xampp.conf and find the below tag:

# Close XAMPP sites here
<LocationMatch "^/(?i:(?:xampp|licenses|phpmyadmin|webalizer|server-status|server-info))">
    Order deny,allow
    Deny from all
    Allow from ::1 127.0.0.0/8 
    ErrorDocument 403 /error/HTTP_XAMPP_FORBIDDEN.html.var
</LocationMatch>

and add

"Allow from all"

after Allow from ::1 127.0.0.0/8 {line}

Restart xampp, and you are done.

In later versions of Xampp

...you can simply remove this part

#
# New XAMPP security concept
#
<LocationMatch "^/(?i:(?:xampp|security|licenses|phpmyadmin|webalizer|server-status|server-info))">
        Require local
    ErrorDocument 403 /error/XAMPP_FORBIDDEN.html.var
</LocationMatch>

from the same file and it should work over the local network.

How do I install Composer on a shared hosting?

It depends on the host, but you probably simply can't (you can't on my shared host on Rackspace Cloud Sites - I asked them).

What you can do is set up an environment on your dev machine that roughly matches your shared host, and do all of your management through the command line locally. Then when everything is set (you've pulled in all the dependencies, updated, managed with git, etc.) you can "push" that to your shared host over (s)FTP.

Difference between virtual and abstract methods

Abstract Method:

  • If an abstract method is defined in a class, then the class should declare as an abstract class.

  • An abstract method should contain only method definition, should not Contain the method body/implementation.

  • An abstract method must be over ride in the derived class.

Virtual Method:

  • Virtual methods can be over ride in the derived class but not mandatory.
  • Virtual methods must have the method body/implementation along with the definition.

Example:

public abstract class baseclass
        {
            public abstract decimal getarea(decimal Radius);

            public virtual decimal interestpermonth(decimal amount)
            {
                return amount*12/100;
            }

            public virtual decimal totalamount(decimal Amount,decimal principleAmount)
            {
                return Amount + principleAmount;
            }
        }

        public class derivedclass:baseclass
        {
            public override decimal getarea(decimal Radius)
            {
                return 2 * (22 / 7) * Radius;
            }

            public override decimal interestpermonth(decimal amount)
            {
                return amount * 14 / 100;
            }
        }

React - uncaught TypeError: Cannot read property 'setState' of undefined

There are two solutions of this issue:

The first solution is add a constructor to your component and bind your function like bellow:

constructor(props) {
        super(props);

        ...

        this.delta = this.delta.bind(this);
    }

So do this:

this.delta = this.delta.bind(this); 

Instead of this:

this.delta.bind(this);

The second solution is to use an arrow function instead:

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

Actually arrow function DOES NOT bind it’s own this. Arrow Functions lexically bind their context so this actually refers to the originating context.

For more information about bind function:

Bind function Understanding JavaScript Bind ()

For more information about arrow function:

Javascript ES6 — Arrow Functions and Lexical this

Drawing a dot on HTML5 canvas

For performance reasons, don't draw a circle if you can avoid it. Just draw a rectangle with a width and height of one:

ctx.fillRect(10,10,1,1); // fill in the pixel at (10,10)

How to get $HOME directory of different user in bash script?

This works in Linux. Not sure how it behaves in other *nixes.

  getent passwd "${OTHER_USER}"|cut -d\: -f 6

Multiple Image Upload PHP form with one input

Multipal image uplode with other taBLE $sql1 = "INSERT INTO event(title) VALUES('$title')";

        $result1 = mysqli_query($connection,$sql1) or die(mysqli_error($connection));
        $lastid= $connection->insert_id;
        foreach ($_FILES["file"]["error"] as $key => $error) {
            if ($error == UPLOAD_ERR_OK ){
                $name = $lastid.$_FILES['file']['name'][$key];
                $target_dir = "photo/";
                $sql2 = "INSERT INTO photos(image,eventid) VALUES ('".$target_dir.$name."','".$lastid."')";
                $result2 = mysqli_query($connection,$sql2) or die(mysqli_error($connection));
                move_uploaded_file($_FILES['file']['tmp_name'][$key],$target_dir.$name);
            }
        }

And how to fetch

$query = "SELECT * FROM event ";
$result = mysqli_query($connection,$query) or die(mysqli_error());


  if($result->num_rows > 0) {
      while($r = mysqli_fetch_assoc($result)){
        $eventid= $r['id'];
        $sqli="select id,image from photos where eventid='".$eventid."'";
        $resulti=mysqli_query($connection,$sqli);
        $image_json_array = array();
        while($row = mysqli_fetch_assoc($resulti)){
            $image_id = $row['id'];
            $image_name = $row['image'];
            $image_json_array[] = array("id"=>$image_id,"name"=>$image_name);
        }
        $msg1[] = array ("imagelist" => $image_json_array);

      }

in ajax $(document).ready(function(){ $('#addCAT').validate({ rules:{name:required:true}submitHandler:function(form){var formurl = $(form).attr('action'); $.ajax({ url: formurl,type: "POST",data: new FormData(form),cache: false,processData: false,contentType: false,success: function(data) {window.location.href="{{ url('admin/listcategory')}}";}}); } })})

How to disable or enable viewpager swiping in android

Disable swipe progmatically by-

    final View touchView = findViewById(R.id.Pager); 
    touchView.setOnTouchListener(new View.OnTouchListener() 
    {         
        @Override
        public boolean onTouch(View v, MotionEvent event)
        { 
           return true; 
        }
     });

and use this to swipe manually

touchView.setCurrentItem(int index);

How to get df linux command output always in GB

You can use the -B option.

Man page of df:

-B, --block-size=SIZE use SIZE-byte blocks

All together,

df -BG

Convert ascii value to char

for (int i = 0; i < 5; i++){
    int asciiVal = rand()%26 + 97;
    char asciiChar = asciiVal;
    cout << asciiChar << " and ";
}

How to check if a variable is empty in python?

See also this previous answer which recommends the not keyword

How to check if a list is empty in Python?

It generalizes to more than just lists:

>>> a = ""
>>> not a
True

>>> a = []
>>> not a
True

>>> a = 0
>>> not a
True

>>> a = 0.0
>>> not a
True

>>> a = numpy.array([])
>>> not a
True

Notably, it will not work for "0" as a string because the string does in fact contain something - a character containing "0". For that you have to convert it to an int:

>>> a = "0"
>>> not a
False

>>> a = '0'
>>> not int(a)
True

Java random number with given length

Would that work for you?

public class Main {

public static void main(String[] args) {
    Random r = new Random(System.currentTimeMillis());
    System.out.println(r.nextInt(100000) * 0.000001);
}

}

result e.g. 0.019007

How do I install opencv using pip?

There are two options-

pip install cv2 

or

pip install opencv-python

Hope it helps.

How to declare or mark a Java method as deprecated?

Take a look at the @Deprecated annotation.

Why does GitHub recommend HTTPS over SSH?

Enabling SSH connections over HTTPS if it is blocked by firewall

Test if SSH over the HTTPS port is possible, run this SSH command:

$ ssh -T -p 443 [email protected]
Hi username! You've successfully authenticated, but GitHub does not
provide shell access.

If that worked, great! If not, you may need to follow our troubleshooting guide.

If you are able to SSH into [email protected] over port 443, you can override your SSH settings to force any connection to GitHub to run though that server and port.

To set this in your ssh config, edit the file at ~/.ssh/config, and add this section:

Host github.com
  Hostname ssh.github.com
  Port 443

You can test that this works by connecting once more to GitHub:

$ ssh -T [email protected]
Hi username! You've successfully authenticated, but GitHub does not
provide shell access.

From Authenticating to GitHub / Using SSH over the HTTPS port

JavaScript code to stop form submission

Lets say you have a form similar to this

<form action="membersDeleteAllData.html" method="post">
    <button type="submit" id="btnLoad" onclick="confirmAction(event);">ERASE ALL DATA</button>
</form>

Here is the javascript for the confirmAction function

<script type="text/javascript">
    function confirmAction(e)
    {
        var confirmation = confirm("Are you sure about this ?") ;

        if (!confirmation)
        {
            e.preventDefault() ;
            returnToPreviousPage();
        }

        return confirmation ;
    }
</script>

This one works on Firefox, Chrome, Internet Explorer(edge), Safari, etc.

If that is not the case let me know

Error: Registry key 'Software\JavaSoft\Java Runtime Environment'\CurrentVersion'?

I ran into this issue after updating the Java JDK, but had not yet restarted my command prompt. After restarting the command prompt, everything worked fine. Presumably, because the PATH variable need to be reset after the JDK update.

Get changes from master into branch in Git

You have a couple options. git rebase master aqonto the branch which will keep the commit names, but DO NOT REBASE if this is a remote branch. You can git merge master aq if you don't care about keeping the commit names. If you want to keep the commit names and it is a remote branch git cherry-pick <commit hash> the commits onto your branch.

Deleting queues in RabbitMQ

There is rabbitmqadmin which is nice to work from console.

If you ssh/log into server where you have rabbit installed, you can download it from:

http://{server}:15672/cli/rabbitmqadmin

and save it into /usr/local/bin/rabbitmqadmin

Then you can run

rabbitmqadmin -u {user} -p {password} -V {vhost} delete queue name={name}

Usually it requires sudo.

If you want to avoid typing your user name and password, you can use config

rabbitmqadmin -c /var/lib/rabbitmq/.rabbitmqadmin.conf -V {vhost} delete queue name={name}

All that under assumption that you have file ** /var/lib/rabbitmq/.rabbitmqadmin.conf** and have bare minumum

hostname = localhost
port = 15672
username = {user}
password = {password}

EDIT: As of comment from @user299709, it might be helpful to point out that user must be tagged as 'administrator' in rabbit. (https://www.rabbitmq.com/management.html)

`React/RCTBridgeModule.h` file not found

Make sure you disable Parallelise Build and add React target above your target

enter image description here

How to change default Anaconda python environment

I got this when installing a library using anaconda. My version went from Python 3.* to 2.7 and a lot of my stuff stopped working. The best solution I found was to first see the most recent version available:

conda search python

Then update to the version you want:

conda install python=3.*.*

Source: http://chris35wills.github.io/conda_python_version/

Other helpful commands:

conda info
python --version

How to import a module in Python with importlib.import_module

For relative imports you have to:

  • a) use relative name
  • b) provide anchor explicitly

    importlib.import_module('.c', 'a.b')
    

Of course, you could also just do absolute import instead:

importlib.import_module('a.b.c')

regular expression to validate datetime format (MM/DD/YYYY)

Try your regex with a tool like http://jsregex.com/ (There is many) or better, a unit test.

For a naive validation:

function validateDate(testdate) {
    var date_regex = /^\d{2}\/\d{2}\/\d{4}$/ ;
    return date_regex.test(testdate);
}

In your case, to validate (MM/DD/YYYY), with a year between 1900 and 2099, I'll write it like that:

function validateDate(testdate) {
    var date_regex = /^(0[1-9]|1[0-2])\/(0[1-9]|1\d|2\d|3[01])\/(19|20)\d{2}$/ ;
    return date_regex.test(testdate);
}

How to add extra whitespace in PHP?

To render more than one whitespace on most web browsers use &nbsp; instead of normal white spaces.

echo "<p>Hello &nbsp;&nbsp;&nbsp; punt"; // This will render as Hello   Punt (with 4 white spaces)
echo "<p> Hello       punt"; // This will render as Hello punt (with one space)

For showing data in raw format (with exact number of spaces and "enters") use HTML <pre> tag.

echo "<pre>Hello        punt</pre>"; //Will render exactly as written here (8 white spaces)

Or you can use some CSS to style current block, not to break text or strip spaces (I don't know, but this one)

Any way you do the output will be the same but the browser itself strips double white spaces and renders as one.

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

For files in a directory, you can use things like:

if exist *.csv echo "csv file found"

or

if not exist *.csv goto nofile

How can I add new item to the String array?

String a []=new String[1];

  a[0].add("kk" );
  a[1].add("pp");

Try this one...

What is a method group in C#?

A method group is the name for a set of methods (that might be just one) - i.e. in theory the ToString method may have multiple overloads (plus any extension methods): ToString(), ToString(string format), etc - hence ToString by itself is a "method group".

It can usually convert a method group to a (typed) delegate by using overload resolution - but not to a string etc; it doesn't make sense.

Once you add parentheses, again; overload resolution kicks in and you have unambiguously identified a method call.

No function matches the given name and argument types

That error means that a function call is only matched by an existing function if all its arguments are of the same type and passed in same order. So if the next f() function

create function f() returns integer as $$ 
    select 1;
$$ language sql;

is called as

select f(1);

It will error out with

ERROR:  function f(integer) does not exist
LINE 1: select f(1);
               ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

because there is no f() function that takes an integer as argument.

So you need to carefully compare what you are passing to the function to what it is expecting. That long list of table columns looks like bad design.

Oracle Insert via Select from multiple tables where one table may not have a row

Outter joins don't work "as expected" in that case because you have explicitly told Oracle you only want data if that criteria on that table matches. In that scenario, the outter join is rendered useless.

A work-around

INSERT INTO account_type_standard 
  (account_type_Standard_id, tax_status_id, recipient_id) 
VALUES( 
  (SELECT account_type_standard_seq.nextval FROM DUAL),
  (SELECT tax_status_id FROM tax_status WHERE tax_status_code = ?), 
  (SELECT recipient_id FROM recipient WHERE recipient_code = ?)
)

[Edit] If you expect multiple rows from a sub-select, you can add ROWNUM=1 to each where clause OR use an aggregate such as MAX or MIN. This of course may not be the best solution for all cases.

[Edit] Per comment,

  (SELECT account_type_standard_seq.nextval FROM DUAL),

can be just

  account_type_standard_seq.nextval,

android.os.FileUriExposedException: file:///storage/emulated/0/test.txt exposed beyond app through Intent.getData()

My Solution was to 'Uri.parse' the File Path as String, instead of using Uri.fromFile().

String storage = Environment.getExternalStorageDirectory().toString() + "/test.txt";
File file = new File(storage);
Uri uri;
if (Build.VERSION.SDK_INT < 24) {
    uri = Uri.fromFile(file);
} else {
    uri = Uri.parse(file.getPath()); // My work-around for new SDKs, worked for me in Android 10 using Solid Explorer Text Editor as the external editor.
}
Intent viewFile = new Intent(Intent.ACTION_VIEW);
viewFile.setDataAndType(uri, "text/plain");
startActivity(viewFile);

Seems that fromFile() uses A file pointer, which I suppose could be insecure when memory addresses are exposed to all apps. But A file path String never hurt anybody, so it works without throwing FileUriExposedException.

Tested on API levels 9 to 29! Successfully opens the text file for editing in another app. Does not require FileProvider, nor the Android Support Library at all.

How to call a stored procedure (with parameters) from another stored procedure without temp table

You can call Stored Procedure like this inside Stored Procedure B.

CREATE PROCEDURE spA
@myDate DATETIME
AS
    EXEC spB @myDate

RETURN 0

How can I create a two dimensional array in JavaScript?

 var items = [
      ["January 01", 42.5],
      ["February 01",  44.3],
      ["March 01",  28.7],
      ["April 01",  44.3],
      ["May 01",  22.9],
      ["June 01",  54.4],
      ["July 01",  69.3],
      ["August 01",  19.1],
      ["September 01",  82.5],
      ["October 01",  53.2],
      ["November 01",  75.9],
      ["December 01",  58.7]

    ];
  alert(items[1][0]); // February 01
  alert(items[5][1]); // 54.4

findAll() in yii

if you user $criteria, I recommend blow usage:

$criteria = new CDbCriteria();
$criteria->compare('email_id', 101);
$comments = EmailArchive::model()->findAll($criteria);

Jackson: how to prevent field serialization

Starting with Jackson 2.6, a property can be marked as read- or write-only. It's simpler than hacking the annotations on both accessors and keeps all the information in one place:

public class User {
    @JsonProperty(access = JsonProperty.Access.WRITE_ONLY)
    private String password;
}

Spring @PropertySource using YAML

i had this similar problem. I'm using SpringBoot 2.4.1. If you face similar problem i.e. cannot load yml files, try adding this class-level annotation in your test.

@SpringJUnitConfig(
    classes = { UserAccountPropertiesTest.TestConfig.class },
    initializers = { ConfigDataApplicationContextInitializer.class }
)
class UserAccountPropertiesTest {

    @Configuration
    @EnableConfigurationProperties(UserAccountProperties.class)
    static class TestConfig { }

    @Autowired
    UserAccountProperties userAccountProperties;

    @Test
    void getAccessTokenExpireIn() {
       assertThat(userAccountProperties.getAccessTokenExpireIn()).isEqualTo(120);
    }

    @Test
    void getRefreshTokenExpireIn() {
        assertThat(userAccountProperties.getRefreshTokenExpireIn()).isEqualTo(604800);
    }
}

the ConfigDataApplicationContextInitializer from import org.springframework.boot.test.context.ConfigDataApplicationContextInitializer; is the one that "help" translate the yml files i think.

I'm able to run my test successfully.

Parsing JSON array into java.util.List with Gson

Definitely the easiest way to do that is using Gson's default parsing function fromJson().

There is an implementation of this function suitable for when you need to deserialize into any ParameterizedType (e.g., any List), which is fromJson(JsonElement json, Type typeOfT).

In your case, you just need to get the Type of a List<String> and then parse the JSON array into that Type, like this:

import java.lang.reflect.Type;
import com.google.gson.reflect.TypeToken;

JsonElement yourJson = mapping.get("servers");
Type listType = new TypeToken<List<String>>() {}.getType();

List<String> yourList = new Gson().fromJson(yourJson, listType);

In your case yourJson is a JsonElement, but it could also be a String, any Reader or a JsonReader.

You may want to take a look at Gson API documentation.

Upgrade Node.js to the latest version on Mac OS

On macOS the homebrew recommended way is to run

brew install node
npm install -g npm@latest

Screenshot of Terminal Commands

Keep placeholder text in UITextField on input in IOS

Instead of using the placeholder text, you'll want to set the actual text property of the field to MM/YYYY, set the delegate of the text field and listen for this method:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {     // update the text of the label } 

Inside that method, you can figure out what the user has typed as they type, which will allow you to update the label accordingly.

Return value from exec(@sql)

Was playing with this today... I beleive you can also use @@ROWCOUNT, like this:

DECLARE @SQL VARCHAR(50)
DECLARE @Rowcount INT
SET @SQL = 'SELECT 1 UNION SELECT 2'
EXEC(@SQL)
SET @Rowcount = @@ROWCOUNT
SELECT @Rowcount

Then replace the 'SELECT 1 UNION SELECT 2' with your actual select without the count. I'd suggest just putting 1 in your select, like this:

SELECT 1
FROM dbo.Comm_Services
WHERE....
....

(as opposed to putting SELECT *)

Hope that helps.

Property '...' has no initializer and is not definitely assigned in the constructor

Just go to tsconfig.json and set

"strictPropertyInitialization": false

to get rid of the compilation error.

Otherwise you need to initialize all your variables which is a little bit annoying

Start an external application from a Google Chrome Extension?

I go for hypothesys since I can't verify now.

With Apache, if you make a php script on your local machine calling your executable, and then call this script via POST or GET via html/javascript?

would it function?

let me know.

Rename a file using Java

For Java 1.6 and lower, I believe the safest and cleanest API for this is Guava's Files.move.

Example:

File newFile = new File(oldFile.getParent(), "new-file-name.txt");
Files.move(oldFile.toPath(), newFile.toPath());

The first line makes sure that the location of the new file is the same directory, i.e. the parent directory of the old file.

EDIT: I wrote this before I started using Java 7, which introduced a very similar approach. So if you're using Java 7+, you should see and upvote kr37's answer.

Format output string, right alignment

It can be achieved by using rjust:

line_new = word[0].rjust(10) + word[1].rjust(10) + word[2].rjust(10)

Clearing content of text file using C#

Just open the file with the FileMode.Truncate flag, then close it:

using (var fs = new FileStream(@"C:\path\to\file", FileMode.Truncate))
{
}

JavaFX Panel inside Panel auto resizing

After hours of searching and testing finally got it just after posting the question!

You can use the "AnchorPane.topAnchor, AnchorPane.bottomAnchor, AnchorPane.leftAnchor, AnchorPane.rightAnchor" fxml commands with the value "0.0" to fit/stretch/align the child elements inside a AnchorPane. So, these commands tell to child element to follow its parent while resizing.

My updated code Main.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<AnchorPane fx:id="anchorPane" xmlns:fx="http://javafx.com/fxml" fx:controller="app.MainController">
    <!--<StackPane fx:id="stackPane" ></StackPane>--> <!-- replace with the following -->
    <StackPane fx:id="stackPane" AnchorPane.topAnchor="0.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" ></StackPane>
</AnchorPane>

Here is the result:

enter image description here

For api documentation: http://docs.oracle.com/javafx/2/api/javafx/scene/layout/AnchorPane.html

How to enable directory listing in apache web server

I had to disable selinux to make this work. Note. The system needs to be rebooted for selinux to take effect.

How to insert a text at the beginning of a file?

With the echo approach, if you are on macOS/BSD like me, lose the -n switch that other people suggest. And I like to define a variable for the text.

So it would be like this:

Header="my complex header that may have difficult chars \"like these quotes\" and line breaks \n\n "

{ echo "$Header"; cat "old.txt"; } > "new.txt"
mv new.txt old.txt

How can I define colors as variables in CSS?

People keep upvoting my answer, but it's a terrible solution compared to the joy of sass or less, particularly given the number of easy to use gui's for both these days. If you have any sense ignore everything I suggest below.

You could put a comment in the css before each colour in order to serve as a sort of variable, which you can change the value of using find/replace, so...

At the top of the css file

/********************* Colour reference chart****************
*************************** comment ********* colour ******** 

box background colour       bbg              #567890
box border colour           bb               #abcdef
box text colour             bt               #123456

*/

Later in the CSS file

.contentBox {background: /*bbg*/#567890; border: 2px solid /*bb*/#abcdef; color:/*bt*/#123456}

Then to, for example, change the colour scheme for the box text you do a find/replace on

/*bt*/#123456

Invalidating JSON Web Tokens

Unique per user string, and global string hashed together

to serve as the JWT secret portion allow both individual and global token invalidation. Maximum flexibility at the cost of a db lookup/read during request auth. Also easy to cache as well, since they are seldom changing.

Here's an example:

HEADER:ALGORITHM & TOKEN TYPE

{
  "alg": "HS256",
  "typ": "JWT"
}
PAYLOAD:DATA

{
  "sub": "1234567890",
  "some": "data",
  "iat": 1516239022
}
VERIFY SIGNATURE

HMACSHA256(
  base64UrlEncode(header) + "." +
  base64UrlEncode(payload), 
  HMACSHA256('perUserString'+'globalString')
)

where HMACSHA256 is your local crypto sha256
  nodejs 
    import sha256 from 'crypto-js/sha256';
    sha256(message);

for example usage see https://jwt.io (not sure they handle dynamic 256 bit secrets)

Preferred way of loading resources in Java

Well, it partly depends what you want to happen if you're actually in a derived class.

For example, suppose SuperClass is in A.jar and SubClass is in B.jar, and you're executing code in an instance method declared in SuperClass but where this refers to an instance of SubClass. If you use this.getClass().getResource() it will look relative to SubClass, in B.jar. I suspect that's usually not what's required.

Personally I'd probably use Foo.class.getResourceAsStream(name) most often - if you already know the name of the resource you're after, and you're sure of where it is relative to Foo, that's the most robust way of doing it IMO.

Of course there are times when that's not what you want, too: judge each case on its merits. It's just the "I know this resource is bundled with this class" is the most common one I've run into.

How can I see the raw SQL queries Django is running?

No other answer covers this method, so:

I find by far the most useful, simple, and reliable method is to ask your database. For example on Linux for Postgres you might do:

sudo su postgres
tail -f /var/log/postgresql/postgresql-8.4-main.log

Each database will have slightly different procedure. In the database logs you'll see not only the raw SQL, but any connection setup or transaction overhead django is placing on the system.

Display a table/list data dynamically in MVC3/Razor from a JsonResult?

You can do this easily with the KoGrid plugin for KnockoutJS.

<script type="text/javascript">
    $(function () {
        window.viewModel = {
            myObsArray: ko.observableArray([
                { id: 1, firstName: 'John', lastName: 'Doe', createdOn: '1/1/2012', birthday: '1/1/1977', salary: 40000 },
                { id: 1, firstName: 'Jane', lastName: 'Harper', createdOn: '1/2/2012', birthday: '2/1/1976', salary: 45000 },
                { id: 1, firstName: 'Jim', lastName: 'Carrey', createdOn: '1/3/2012', birthday: '3/1/1985', salary: 60000 },
                { id: 1, firstName: 'Joe', lastName: 'DiMaggio', createdOn: '1/4/2012', birthday: '4/1/1991', salary: 70000 }
            ])
        };

        ko.applyBindings(viewModel);
    });
</script>

<div data-bind="koGrid: { data: myObsArray }">

Sample

How do I order my SQLITE database in descending order, for an android app?

SQLite ORDER BY clause is used to sort the data in an ascending or descending order, based on one or more columns. Cursor c = scoreDb.query(DATABASE_TABLE, rank, null, null, null, null, yourColumn+" DESC");

SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.query(
            TABLE_NAME,
            rank,
            null,
            null,
            null,
            null,
            COLUMN + " DESC",
            null);

How to remove unused dependencies from composer?

In fact, it is very easy.

composer update

will do all this for you, but it will also update the other packages.

To remove a package without updating the others, specifiy that package in the command, for instance:

composer update monolog/monolog

will remove the monolog/monolog package.

Nevertheless, there may remain some empty folders or files that cannot be removed automatically, and that have to be removed manually.

Laravel 5.2 - pluck() method returns array

In Laravel 5.1+, you can use the value() instead of pluck.

To get first occurence, You can either use

DB::table('users')->value('name');

or use,

DB::table('users')->where('id', 1)->pluck('name')->first();

How to disable Home and other system buttons in Android?

It used to be possible to disable the Home button, but now it isn't. It's due to malicious software that would trap the user.

You can see more detailes here: Disable Home button in Android 4.0+

Finally, the Back button can be disabled, as you can see in this other question: Disable back button in android

Http Servlet request lose params from POST body after read it once

Just overwriting of getInputStream() did not work in my case. My server implementation seems to parse parameters without calling this method. I did not find any other way, but re-implement the all four getParameter* methods as well. Here is the code of getParameterMap (Apache Http Client and Google Guava library used):

@Override
public Map<String, String[]> getParameterMap() {
    Iterable<NameValuePair> params = URLEncodedUtils.parse(getQueryString(), NullUtils.UTF8);

    try {
        String cts = getContentType();
        if (cts != null) {
            ContentType ct = ContentType.parse(cts);
            if (ct.getMimeType().equals(ContentType.APPLICATION_FORM_URLENCODED.getMimeType())) {
                List<NameValuePair> postParams = URLEncodedUtils.parse(IOUtils.toString(getReader()), NullUtils.UTF8);
                params = Iterables.concat(params, postParams);
            }
        }
    } catch (IOException e) {
        throw new IllegalStateException(e);
    }
    Map<String, String[]> result = toMap(params);
    return result;
}

public static Map<String, String[]> toMap(Iterable<NameValuePair> body) {
    Map<String, String[]> result = new LinkedHashMap<>();
    for (NameValuePair e : body) {
        String key = e.getName();
        String value = e.getValue();
        if (result.containsKey(key)) {
            String[] newValue = ObjectArrays.concat(result.get(key), value);
            result.remove(key);
            result.put(key, newValue);
        } else {
            result.put(key, new String[] {value});
        }
    }
    return result;
}

How do C++ class members get initialized if I don't do it explicitly?

First, let me explain what a mem-initializer-list is. A mem-initializer-list is a comma-separated list of mem-initializers, where each mem-initializer is a member name followed by (, followed by an expression-list, followed by a ). The expression-list is how the member is constructed. For example, in

static const char s_str[] = "bodacydo";
class Example
{
private:
    int *ptr;
    string name;
    string *pname;
    string &rname;
    const string &crname;
    int age;

public:
    Example()
        : name(s_str, s_str + 8), rname(name), crname(name), age(-4)
    {
    }
};

the mem-initializer-list of the user-supplied, no-arguments constructor is name(s_str, s_str + 8), rname(name), crname(name), age(-4). This mem-initializer-list means that the name member is initialized by the std::string constructor that takes two input iterators, the rname member is initialized with a reference to name, the crname member is initialized with a const-reference to name, and the age member is initialized with the value -4.

Each constructor has its own mem-initializer-list, and members can only be initialized in a prescribed order (basically the order in which the members are declared in the class). Thus, the members of Example can only be initialized in the order: ptr, name, pname, rname, crname, and age.

When you do not specify a mem-initializer of a member, the C++ standard says:

If the entity is a nonstatic data member ... of class type ..., the entity is default-initialized (8.5). ... Otherwise, the entity is not initialized.

Here, because name is a nonstatic data member of class type, it is default-initialized if no initializer for name was specified in the mem-initializer-list. All other members of Example do not have class type, so they are not initialized.

When the standard says that they are not initialized, this means that they can have any value. Thus, because the above code did not initialize pname, it could be anything.

Note that you still have to follow other rules, such as the rule that references must always be initialized. It is a compiler error to not initialize references.

Regular expression to match characters at beginning of line only

There's are ambiguities in the question.

What is your input string? Is it the entire file? Or is it 1 line at a time? Some of the answers are assuming the latter. I want to answer the former.

What would you like to return from your regular expression? The fact that you want a true / false on whether a match was made? Or do you want to extract the entire line whose start begins with CTR? I'll answer you only want a true / false match.

To do this, we just need to determine if the CTR occurs at either the start of a file, or immediately following a new line.

/(?:^|\n)CTR/

MySQL select one column DISTINCT, with corresponding other columns

SELECT ID,LastName 
From TABLE_NAME 
GROUP BY FirstName 
HAVING COUNT(*) >=1

Routing HTTP Error 404.0 0x80070002

My solution, after trying EVERYTHING:

Bad deployment, an old PrecompiledApp.config was hanging around my deploy location, and making everything not work.

My final settings that worked:

  • IIS 7.5, Win2k8r2 x64,
  • Integrated mode application pool
  • Nothing changes in the web.config - this means no special handlers for routing. Here's my snapshot of the sections a lot of other posts reference. I'm using FluorineFX, so I do have that handler added, but I did not need any others:

    <system.web>
      <compilation debug="true" targetFramework="4.0" />
      <authentication mode="None"/>
    
      <pages validateRequest="false" controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID"/>
      <httpRuntime requestPathInvalidCharacters=""/>
    
      <httpModules>
        <add name="FluorineGateway" type="FluorineFx.FluorineGateway, FluorineFx"/>
      </httpModules>
    </system.web>
      <system.webServer>
        <!-- Modules for IIS 7.0 Integrated mode -->
        <modules>
          <add name="FluorineGateway" type="FluorineFx.FluorineGateway, FluorineFx" />
        </modules>
    
        <!-- Disable detection of IIS 6.0 / Classic mode ASP.NET configuration -->
        <validation validateIntegratedModeConfiguration="false" />
      </system.webServer>
    
  • Global.ashx: (only method of any note)

    void Application_Start(object sender, EventArgs e) {
        // Register routes...
        System.Web.Routing.Route echoRoute = new System.Web.Routing.Route(
              "{*message}",
            //the default value for the message
              new System.Web.Routing.RouteValueDictionary() { { "message", "" } },
            //any regular expression restrictions (i.e. @"[^\d].{4,}" means "does not start with number, at least 4 chars
              new System.Web.Routing.RouteValueDictionary() { { "message", @"[^\d].{4,}" } },
              new TestRoute.Handlers.PassthroughRouteHandler()
           );
    
        System.Web.Routing.RouteTable.Routes.Add(echoRoute);
    }
    
  • PassthroughRouteHandler.cs - this achieved an automatic conversion from http://andrew.arace.info/stackoverflow to http://andrew.arace.info/#stackoverflow which would then be handled by the default.aspx:

    public class PassthroughRouteHandler : IRouteHandler {
    
        public IHttpHandler GetHttpHandler(RequestContext requestContext) {
            HttpContext.Current.Items["IncomingMessage"] = requestContext.RouteData.Values["message"];
            requestContext.HttpContext.Response.Redirect("#" + HttpContext.Current.Items["IncomingMessage"], true);
            return null;
        }
    }