You can use [reflection][1]...

    $r = new ReflectionMethod($className, $methodName);
    $params = $r-&gt;getParameters();
    foreach ($params as $param) {
        //$param is an instance of ReflectionParameter
        echo $param-&gt;getName();
        echo $param-&gt;isOptional();
    }


  [1]: http://www.php.net/manual/en/class.reflectionmethod.php

I have a very large numpy array (containing up to a million elements) like the one below:

    [0,1,6,5,1,2,7,6,2,3,8,7,3,4,9,8,5,6,11,10,6,7,12,11,7,
    8,13,12,8,9,14,13,10,11,16,15,11,12,17,16,12,13,18,17,13,
    14,19,18,15,16,21,20,16,17,22,21,17,18,23,22,18,19,24,23]

and a small dictionary map for replacing some of the elements in the above array

    {4: 0, 9: 5, 14: 10, 19: 15, 20: 0, 21: 1, 22: 2, 23: 3, 24: 0}

I would like to replace some of the elements according to the map above. The numpy array is really large, and only a small subset of the elements (occurring as keys in the dictionary) will be replaced with the corresponding values. What is the fastest way to do this?


Fast replacement of values in a numpy array

Say I make an HTTP request to: `foosite.com` but the port I actually send the request to is 6103 and I DON&#39;T put that port in the `Host` header for example:

    GET /barpage HTTP/1.1
    Host: foosite.com
    Method: GET

Should http server then recognize that I&#39;m trying to talk to it on port 6103? Or since it was omitted in the request header am I gambling on if the server actually recognizes this?

I ask that question to say this: I&#39;ve found that browsers, at least firefox + chrome, put the port in the `Host` header. But the Java app I&#39;m using does not. And when the port is not passed in the `Host` the server responds back thinking I&#39;m on port 80. So who do I need to badger? The server operator, or the Java programmer?

Is Port Number Required in HTTP &quot;Host&quot; Header Parameter?

I can check all available methods for an object like so:

    $methods = get_class_methods($object);

But how can I see which arguments have to be sent to these methods?

Is there a function for this?

Get method&#39;s arguments?

I can check all available methods for an object like so:
<pre><code class="hljs language-ini">$methods = get_class_methods($object);
</code></pre>
But how can I see which arguments have to be sent to these methods?
Is there a function for this?

I expected the following to work but it doesn&#39;t seem to.

    &lt;?php
    
    class Patterns
    {
    	public static const EMAIL = &quot;/^([a-z0-9\+_\-]+)(\.[a-z0-9\+_\-]+)*@([a-z0-9\-]+\.)+[a-z]{2,6}$/ix&quot;;
    	public static const INT = &quot;/^\d+$/&quot;;
    	public static const USERNAME = &quot;/^\w+$/&quot;;
    }

Because it throws this error:

    syntax error, unexpected T_CONST, expecting T_VARIABLE

Can you use static constants inside classes in PHP?

Can someone show me how to get the youtube id out of a url regardless of what other GET variables are in the URL.

Use this video for example: `http://www.youtube.com/watch?v=C4kxS1ksqtw&amp;feature=related`
&lt;br&gt;So between `v=` and before the next `&amp;`



PHP Regex to get youtube video ID?

How do I install the bcmath module on a server? I tried

    yum update php-bcmath

but it said it found nothing.

How to install bcmath module?

I just used array_filter to remove entries that had only the value &#39;&#39; from an array, and now I want to apply certain transformations on it depending on the placeholder starting from 0, but unfortunately it still retains the original index.  I looked for a while and couldn&#39;t see anything, perhaps I just missed the obvious, but my question is...

How can I easily reset the indexes of the array to begin at 0 and go in order in the NEW array, rather than have it retain old indexes?

After array_filter(), how can I reset the keys to go in numerical order starting at 0

I have a date time in a variable. My format is `08/04/2010 22:15:00`. I want to display this like `10.15 PM`. How to do this in PHP?

How to get AM/PM from a datetime in PHP

Let&#39;s say I have a base class named `Entity`.  In that class, I have a static method to retrieve the class name:

    class Entity {
        public static String getClass() {
            return Entity.class.getClass();
        }
    }

Now I have another class extend that.

    class User extends Entity {
    }

I want to get the class name of User:

    System.out.println(User.getClass());

My goal is to see &quot;com.packagename.User&quot; output to the console, but instead I&#39;m going to end up with &quot;com.packagename.Entity&quot; since the Entity class is being referenced directly from the static method.

If this wasn&#39;t a static method, this could easily be solved by using the `this` keyword within the `Entity` class (i.e.: `return this.class.getClass()`).  However, I need this method to remain static.  Any suggestions on how to approach this?

Getting the name of a sub-class from within a super-class

    class Example(object):
        def the_example(self):
            itsProblem = &quot;problem&quot;
    
    theExample = Example()
    print(theExample.itsProblem)

How do I access a class&#39;s variable?  I&#39;ve tried adding this definition:

    def return_itsProblem(self):
        return itsProblem

Yet, that fails also.


How do I access Class member variables in Python?

I get this when I call `toString` on an object I received from a function call. I know the type of the object is encoded in this string, but I don&#39;t know how to read it.

What is this type of encoding called?

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

Hay I have an element like this

    &lt;span class=&#39;a.b&#39;&gt;

Unfortunately this class name comes from an eCommerce application and cannot be changed.

Can I style a class name with a dot in it?

like

    .a.b { }

Styling elements with a dot (.) in the class name

I have an JavaScript object like this:

    id=&quot;1&quot;;
    name = &quot;serdar&quot;;

and I have an Array which contains many objects of above. How can I remove an object from that array such as like that:

    obj[1].remove();




How do I remove an object from an array with JavaScript?

When iterating over an object&#39;s properties, is it safe to delete them while in a for-in loop?

For example:

    for (var key in obj) {
        if (!obj.hasOwnProperty(key)) continue;

        if (shouldDelete(obj[key])) {
            delete obj[key];
        }
    }

In many other languages iterating over an array or dictionary and deleting inside that is unsafe.  Is it okay in JS?

&lt;sup&gt;(I am using Mozilla&#39;s Spidermonkey runtime.)&lt;/sup&gt;

Is it safe to delete an object property while iterating over them?

If I have an `stdObject` say, `$a`.

Sure there&#39;s no problem to assign a new property, `$a`,

    $a-&gt;new_property = $xyz;

But then I want to remove it, so `unset` is of no help here.

So,

    $a-&gt;new_property = null;

is kind of it. But is there a more &#39;elegant&#39; way?

Is it possible to delete an object&#39;s property in PHP?

I am having a problem with PHP at the moment, I am getting this error, 

`Object of class stdClass could not be converted to string` the error occurs when I run this portion of code in my site, 

    function myaccount() {
        $data[&#39;user_data&#39;] = $this-&gt;auth-&gt;get_userdata($this-&gt;uri-&gt;segment(3));
        //var_dump($data[&#39;user_data&#39;]);
        $this-&gt;load-&gt;model(&#39;users_model&#39;);
        $data[&#39;user_info&#39;] = $this-&gt;users_model-&gt;get_user_and_roadmaps_by_id($this-&gt;uri-&gt;segment(3));
        $this-&gt;template-&gt;build(&#39;users/my_account&#39;, $data);
    }

The line in which the error is occuring is this one, 

    $data[&#39;user_data&#39;] = $this-&gt;auth-&gt;get_userdata($this-&gt;uri-&gt;segment(3));

And this line is calling this function, 

 

       function get_userdata() {
            
            $CI =&amp; get_instance();
            
            if(!$this-&gt;logged_in()) {
                return false;
            } else {
                $query = $CI-&gt;db-&gt;get_where(&#39;users&#39;, array(&#39;user_id&#39; =&gt; $CI-&gt;session-&gt;userdata(&#39;user_id&#39;)));
                return $query-&gt;row();
            }
        }

I don&#39;t really now what this problem is, so any help would be great.



Object of class stdClass could not be converted to string

It seems that when I use a numeric type as a key name in an object, it always gets converted to a string. Is there anyway to actually get it to store as a numeric? The normal typecasting does not seem to work.

Example:

    var userId = 1;
    console.log( typeof userId ); // number
    myObject[userId] = &#39;a value&#39;;
    console.dir(myObject);

Dir Output:

    {
        &#39;1&#39;: &#39;a value&#39;
    }


What I **want** is this:

    {
        1: &#39;a value&#39;
    }


Advice?

Is there any way to use a numeric type as an object key?

I program regularly in R in a professional context, and I write packages for clients or co-workers as well. Some of the programmers here have a Java background and insist on doing everything the object-oriented way, using S4 methods. My experience on the other hand is that S4 implementations often perform worse and cause a lot more headache when trying to get the code do what you want it to do. 

I definitely agree that in some cases, you have to be able to construct complex objects or append existing objects in a controlled manner. But most of the time, S4 implementations can easily be done using classic lists as well, without all the hassle like defining standardGeneric, methods, constructors, initializers and the likes.

When do you consider writing S4 implementations for R?

EDIT : For clarity, I do appreciate the answers and the discussion about OO in general in R. OOP can be done in numerous ways in R, but my question is really aimed at the added value of using S4 methods specifically. 

When does it pay off to use S4 methods in R programming

C# methods in interfaces are declared without using the `virtual` keyword, and overridden in the derived class without using the `override` keyword.

Is there a reason for this?  I assume that it is just a language convenience, and obviously the CLR knows how to handle this under the covers (methods are not virtual by default), but are there other technical reasons?

Here is the IL that a derived class generates:

    class Example : IDisposable {
        public void Dispose() { }
    }

    .method public hidebysig newslot virtual final 
            instance void  Dispose() cil managed
    {
      // Code size       2 (0x2)
      .maxstack  8
      IL_0000:  nop
      IL_0001:  ret
    } // end of method Example::Dispose

Notice that the method is declared `virtual` `final` in the IL. 

Why are C# interface methods not declared abstract or virtual?

Can anyone, please, explain to me in very simple terms what a &quot;method&quot; is in Python?

The thing is in many Python tutorials for beginners this word is used in such way as if the beginner already knew what a method is in the context of Python. While I am of course familiar with the general meaning of this word, I have no clue what this term means in Python. So, please, explain to me what the &quot;Pythonian&quot; method is all about.

Some very simple example code would be very much appreciated as a picture is worth thousand words.

  

What is a &quot;method&quot; in Python?

I like using question mark at the end of method/function names in other languages. Java doesn&#39;t let me do this. As a workaround how else can I name boolean returning methods in Java? Using an `is`, `has`, `should`, `can` in the front of a method sound okay for some cases. Is there a better way to name such methods?

For e.g. createFreshSnapshot? 






Naming conventions for Java methods that return boolean

I&#39;ve written a function in C# that does a numerical differentiation. It looks like this:

    public double Diff(double x)
    {
        double h = 0.0000001;
    
        return (Function(x + h) - Function(x)) / h;
    }

I would like to be able to pass in any function, as in:

    public double Diff(double x, function f)
    {
        double h = 0.0000001;
    
        return (f(x + h) - f(x)) / h;
    }

I think this is possible with delegates (maybe?) but I&#39;m not sure how to use them.


C# Passing Function as Argument

For a constructor with a single parameter, is it OK to throw an ArgumentNullException inside the constructor if the parameter is null/empty? OR, should it be thrown in the method that actually uses the argument? Thanks.

Throwing ArgumentNullException in constructor?

### What is this?

This is a collection of questions that come up every now and then about syntax in PHP. This is also a Community Wiki, so everyone is invited to participate in maintaining this list. 

### Why is this?

It used to be hard to find questions about operators and other syntax tokens.&#185;  
The main idea is to have links to existing questions on Stack Overflow, so it&#39;s easier for us to reference them, not to copy over content from the PHP Manual.

Note: Since January 2013, Stack Overflow [does support special characters][1]. Just surround the search terms by quotes, e.g. [`[php] &quot;==&quot; vs &quot;===&quot;`][2]

### **What should I do here?**

If you have been pointed here by someone because you have asked such a question, please find the particular syntax below. The linked pages to the [PHP manual](http://php.net/manual/en/index.php) along with the linked questions will likely answer your question then. If so, you are encouraged to upvote the answer. This list is not meant as a substitute for the help others provided.

## The List

If your particular token is not listed below, you might find it in the [List of Parser Tokens][3].

---

`&amp;` [Bitwise Operators][4] or [References][5]

 - https://stackoverflow.com/questions/1676897
 - https://stackoverflow.com/questions/600202
 - https://stackoverflow.com/questions/2209934/
 - https://stackoverflow.com/questions/2376348
 - https://stackoverflow.com/questions/1006652
 - https://stackoverflow.com/questions/2297592
 - https://stackoverflow.com/questions/2422907
 - https://stackoverflow.com/questions/2478149
 - https://stackoverflow.com/questions/3957584
 - https://stackoverflow.com/questions/4705262
 - https://stackoverflow.com/questions/4705838
 - https://stackoverflow.com/questions/21058439 (&amp;$)

---

`=&amp;` [References][5]

 - https://stackoverflow.com/questions/1768343
 - https://stackoverflow.com/questions/1367454
 - https://stackoverflow.com/questions/3177342
 - https://stackoverflow.com/questions/2081806

---

`&amp;=` [Bitwise Operators][4]

 - https://stackoverflow.com/questions/1367454
 - https://stackoverflow.com/questions/3177342

---

`&amp;&amp;` [Logical Operators][6]

 - https://stackoverflow.com/questions/2803321
 - https://stackoverflow.com/questions/2376348
 - https://stackoverflow.com/questions/4746865
 - https://stackoverflow.com/questions/4502092

---

`%` [Arithmetic Operators][7]

 - https://stackoverflow.com/questions/1934173
 - https://stackoverflow.com/questions/3204919

---

`!!` [Logical Operators][6]

 - https://stackoverflow.com/questions/2127260

---

`@` [Error Control Operators][8]

 - https://stackoverflow.com/questions/1032161
 - https://stackoverflow.com/questions/3551527
 - https://stackoverflow.com/questions/3984864
 - https://stackoverflow.com/questions/4872340
 - https://stackoverflow.com/questions/3621215

---

`?:` [Ternary Operator][9]

 - https://stackoverflow.com/questions/1080247
 - https://stackoverflow.com/questions/1993409
 - https://stackoverflow.com/questions/4055355
 - https://stackoverflow.com/questions/4210187

---

`??` [Null Coalesce Operator][36] (since PHP 7)

 - https://stackoverflow.com/questions/7278835

---

`?string`
`?int`
`?array`
`?bool`
`?float` [Nullable return type declaration][10] (since PHP 7.1)

 - [Nullable return type declaration](https://stackoverflow.com/a/54217328/250259)
 - [Nullable parameter type declaration](https://stackoverflow.com/a/48450841)
 - [php method argument type hinting with question mark (?type)][34]

---

`:` [Alternative syntax for control structures][11], [Ternary Operator][9], [Return Type Declaration](https://www.php.net/manual/en/language.types.declarations.php)

 - https://stackoverflow.com/questions/2908095
 - https://stackoverflow.com/questions/4747761
 - https://stackoverflow.com/questions/40346754

---

`::` [Scope Resolution Operator][12]

 - https://stackoverflow.com/questions/2903564
 - https://stackoverflow.com/questions/2588298
 - https://stackoverflow.com/questions/3173501
 - https://stackoverflow.com/questions/1912902
 - https://stackoverflow.com/questions/4120755
 - https://stackoverflow.com/questions/8734823

---

`\` [Namespaces][13]

 - https://stackoverflow.com/questions/10788400
 - https://stackoverflow.com/questions/4790020

---

`-&gt;` [Classes And Objects][14]

 - https://stackoverflow.com/questions/2588149
 - https://stackoverflow.com/questions/3037526
 - https://stackoverflow.com/questions/3173501
 - https://stackoverflow.com/questions/2316370
 - https://stackoverflow.com/questions/4502587

---

`=&gt;` [Arrays][15]

 - https://stackoverflow.com/questions/1241819
 - https://stackoverflow.com/questions/1655336
 - https://stackoverflow.com/questions/4758791

---

`^` [Bitwise Operators][4]

 - https://stackoverflow.com/questions/2674920
 - https://stackoverflow.com/questions/2724936

---

`&gt;&gt;` [Bitwise Operators][4]

 - https://stackoverflow.com/questions/2790329

---

`&lt;&lt;` [Bitwise Operators][4]

- https://stackoverflow.com/questions/9718689/strange-print-behaviour-in-php

---

`&lt;&lt;&lt;` [Heredoc or Nowdoc][16]

 - https://stackoverflow.com/questions/5539669
 - https://stackoverflow.com/questions/1048481
 - https://stackoverflow.com/questions/3700042
 - https://stackoverflow.com/questions/2090081
 - https://stackoverflow.com/questions/2333779

---

`=` [Assignment Operators][17]

 - https://stackoverflow.com/questions/2063480

---

`==` [Comparison Operators][18]

 - https://stackoverflow.com/questions/80646
 - https://stackoverflow.com/questions/1663451
 - https://stackoverflow.com/questions/2063480
 - https://stackoverflow.com/questions/15813490/

---

`===` [Comparison Operators][18]

 - https://stackoverflow.com/questions/1117967
 - https://stackoverflow.com/questions/80646
 - https://stackoverflow.com/questions/2063480
 - https://stackoverflow.com/questions/15813490/

---

`!==` [Comparison Operators][18]

 - https://stackoverflow.com/questions/1298083
 - https://stackoverflow.com/questions/1139154

---

`!=` [Comparison Operators][18]

 - https://stackoverflow.com/questions/1663451
 - https://stackoverflow.com/questions/1139154
 - https://stackoverflow.com/questions/6356826
 - https://stackoverflow.com/questions/9671785/what-is-the-difference-between-and

---

`&lt;&gt;` [Comparison Operators][18]

 - https://stackoverflow.com/questions/249312
 - https://stackoverflow.com/questions/589391
 - https://stackoverflow.com/questions/9671785
 - https://stackoverflow.com/questions/15813490/

---

`&lt;=&gt;` [Comparison Operators][18] (since PHP 7.0)

 - [Spaceship (three way comparison) operator][19]

---

`|` [Bitwise Operators][4]

 - https://stackoverflow.com/questions/2233835
 - https://stackoverflow.com/questions/13811922

---

`||` [Logical Operators][6]

 - https://stackoverflow.com/questions/2233835
 - https://stackoverflow.com/questions/4502092
 - https://stackoverflow.com/questions/5666741
 - https://stackoverflow.com/questions/12213283

---

`~` [Bitwise Operators][4]

 - https://stackoverflow.com/questions/1967360

---

`+` [Arithmetic Operators][7], [Array Operators][20]

 - https://stackoverflow.com/questions/2140090

---

`+=` and `-=` [Assignment Operators][17]

 - https://stackoverflow.com/questions/542995
 - https://stackoverflow.com/questions/7140158

---

`++` and `--` [Incrementing/Decrementing Operators][21]

 - https://stackoverflow.com/questions/1968371
 - [Answer below][22]

---

`.=` [Assignment Operators][17]

 - https://stackoverflow.com/questions/2202331
 - https://stackoverflow.com/questions/1241432

---

`.` [String Operators][23]

 - https://stackoverflow.com/questions/1466408
 - https://stackoverflow.com/questions/6484968

---

`,` [Function Arguments][24]

 - https://stackoverflow.com/questions/1466408

`,` [Variable Declarations][25]

 - https://stackoverflow.com/questions/41383218

---

`$$` [Variable Variables][26]

 - https://stackoverflow.com/questions/2715654
 - https://stackoverflow.com/questions/4169882
 - https://stackoverflow.com/questions/4891872

---

`` ` `` [Execution Operator][27]

 - https://stackoverflow.com/questions/6002296

---

`&lt;?=` [Short Open Tags][28]

 - https://stackoverflow.com/questions/1963901
 - https://stackoverflow.com/questions/2020445
 - https://stackoverflow.com/questions/1959256/what-does-mean

---

`[]` [Arrays][15] (short syntax since PHP 5.4)

 - https://stackoverflow.com/q/20709055/2758197
 - https://stackoverflow.com/questions/6933345
 - https://stackoverflow.com/questions/2431629
 - https://stackoverflow.com/questions/3908576
 - [Shorthand for arrays: literal `$var = []` empty array](https://stackoverflow.com/questions/4271874)


---

`&lt;?` [Opening and Closing tags][29]

 - https://stackoverflow.com/questions/200640


---

`...` [Argument unpacking][30] (since PHP 5.6)

---
`**` [Exponentiation][31] (since PHP 5.6)

---
`#` [One-line shell-style comment][32]

 - [Can I use hashes for comments in PHP?][33]

---
`?-&gt;` [NullSafe Operator Calls][35] (since PHP 8.0)

- https://stackoverflow.com/questions/62178354/what-does-this-symbol-mean-in-php-within-an-object-or-null-value

---


  [1]: https://meta.stackexchange.com/questions/160100/a-new-search-engine-for-stack-exchange
  [2]: https://stackoverflow.com/search?q=%5Bphp%5D%20%22===%22%20vs%20%22==%22
  [3]: http://secure.php.net/manual/en/tokens.php
  [4]: http://secure.php.net/manual/en/language.operators.bitwise.php
  [5]: http://secure.php.net/manual/en/language.references.php
  [6]: http://secure.php.net/manual/en/language.operators.logical.php
  [7]: http://secure.php.net/manual/en/language.operators.arithmetic.php
  [8]: http://secure.php.net/manual/en/language.operators.errorcontrol.php
  [9]: http://php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary
  [10]: https://www.php.net/manual/en/migration71.new-features.php
  [11]: http://secure.php.net/manual/en/control-structures.alternative-syntax.php
  [12]: http://secure.php.net/manual/en/language.oop5.paamayim-nekudotayim.php
  [13]: http://php.net/namespaces
  [14]: http://secure.php.net/manual/en/language.oop5.php
  [15]: http://secure.php.net/manual/en/language.types.array.php
  [16]: http://php.net/manual/en/language.types.string.php#language.types.string.syntax.heredoc
  [17]: http://secure.php.net/manual/en/language.operators.assignment.php
  [18]: http://secure.php.net/manual/en/language.operators.comparison.php
  [19]: https://stackoverflow.com/a/31298778
  [20]: http://secure.php.net/manual/en/language.operators.array.php
  [21]: http://secure.php.net/manual/en/language.operators.increment.php
  [22]: https://stackoverflow.com/a/3737177
  [23]: http://secure.php.net/manual/en/language.operators.string.php
  [24]: http://php.net/manual/en/functions.arguments.php
  [25]: http://php.net/manual/en/language.variables.scope.php
  [26]: http://php.net/manual/en/language.variables.variable.php
  [27]: http://php.net/manual/en/language.operators.execution.php
  [28]: http://php.net/manual/en/ini.core.php#ini.short-open-tag
  [29]: http://secure.php.net/manual/en/language.basic-syntax.php
  [30]: http://php.net/manual/en/functions.arguments.php#functions.variable-arg-list
  [31]: http://secure.php.net/manual/en/migration56.new-features.php#migration56.new-features.exponentiation
  [32]: http://php.net/manual/en/language.basic-syntax.comments.php
  [33]: https://stackoverflow.com/questions/9093609/can-i-use-hashes-for-comments-in-php
  [34]: https://stackoverflow.com/questions/48881489/php-method-argument-type-hinting-with-question-mark-type
  [35]: https://stackoverflow.com/a/62178856/250259
  [36]: https://www.php.net/manual/en/migration70.new-features.php#migration70.new-features.null-coalesce-op

Reference — What does this symbol mean in PHP?

I reckon that the handle `$@` in a shell script is an array of all arguments given to the script. Is this true? 

I ask because I normally use search engines to gather information, but I can&#39;t google for `$@` and I have grown too accustomed to easily getting served everything.

&lt;!-- character limits are dumb: https://meta.stackexchange.com/a/90014/238319 --&gt;

What is $@ in Bash?

In Python, how do I convert a list to `*args`?

I need to know because the function

    scikits.timeseries.lib.reportlib.Report.__init__(*args)

wants several time_series objects passed as `*args`, whereas I have a list of timeseries objects.

Content Type	Original Author	Original Content on Stackoverflow
Question	Rakward	View Question on Stackoverflow
Solution 1 - Php	ircmaxell	View Answer on Stackoverflow

Get method's arguments?

Php Problem Overview

Php Solutions

Solution 1 - Php

Is Port Number Required in HTTP "Host" Header Parameter?

Fast replacement of values in a numpy array

Attributions