What is globals php

PHP Variables Scope

In PHP, variables can be declared anywhere in the script.

The scope of a variable is the part of the script where the variable can be referenced/used.

PHP has three different variable scopes:

Global and Local Scope

A variable declared outside a function has a GLOBAL SCOPE and can only be accessed outside a function:

Example

Variable with global scope:

function myTest() // using x inside this function will generate an error
echo «

Variable x inside function is: $x

«;
>
myTest();

echo «

Variable x outside function is: $x

«;
?>

A variable declared within a function has a LOCAL SCOPE and can only be accessed within that function:

Example

Variable with local scope:

function myTest() $x = 5; // local scope
echo «

Variable x inside function is: $x

«;
>
myTest();

// using x outside the function will generate an error
echo «

Variable x outside function is: $x

«;
?>

You can have local variables with the same name in different functions, because local variables are only recognized by the function in which they are declared.

PHP The global Keyword

The global keyword is used to access a global variable from within a function.

To do this, use the global keyword before the variables (inside the function):

Example

function myTest() global $x, $y;
$y = $x + $y;
>

myTest();
echo $y; // outputs 15
?>

PHP also stores all global variables in an array called $GLOBALS[index] . The index holds the name of the variable. This array is also accessible from within functions and can be used to update global variables directly.

The example above can be rewritten like this:

Example

function myTest() $GLOBALS[‘y’] = $GLOBALS[‘x’] + $GLOBALS[‘y’];
>

myTest();
echo $y; // outputs 15
?>

PHP The static Keyword

Normally, when a function is completed/executed, all of its variables are deleted. However, sometimes we want a local variable NOT to be deleted. We need it for a further job.

To do this, use the static keyword when you first declare the variable:

Example

Then, each time the function is called, that variable will still have the information it contained from the last time the function was called.

Note: The variable is still local to the function.

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What is the use of $GLOBALS in PHP ?

A lot of functionality of WordPress is already dependent on global variables, and looking into the source code it would seem that the function is actually setting a global variable called . functions.php: and then in header.php you could have: I should also point out that by the looks of the variables you have, you probably only need because the others can all be retrieved using WordPress functions and are just redundant.

What is the use of $GLOBALS in PHP ?

In this article, we will discuss $GLOBALS in PHP. $GLOBALS is a superglobal variable used to access global variables from anywhere in the PHP program. PHP stores all global variables in an array called $GLOBALS[index].

Example: PHP Program to demonstrates $GLOBALS.

PHP

Example 2: PHP program to perform arithmetic operations using $GLOBALS.

PHP

Are global variables in PHP considered bad practice? If, The best way to avoid globals is a philosophy called Dependency Injection. This is where we pass the tools we need into the function or class. function foo (\Bar …

Alternative to Globals

I have a set of variables that need to be accessible across my site. While I could declare them in my header.php file, I would prefer to define them in functions.php, or just not in a template file (view). Everything I read says DON’T USE GLOBAL’s. fine. But then what is the best way define these variables?

Here’s what I’m looking to define:

 global $favorites_array; global $user; global $user_id; global $user_name; global $uri; $user = wp_get_current_user(); $user_name = $user->user_login; $user_id = $user->ID; $user_id = get_current_user_id(); $uri = $_SERVER['REQUEST_URI']; 

The common advice you’ve found against using globals (or avoiding them whenever possible) is generally good advice, and you are correct to look first for alternatives rather than resorting to using them. The most common alternative is to pass the values into your functions as parameters.

A lot of functionality of WordPress is already dependent on global variables, and looking into the source code it would seem that the function wp_get_current_user() is actually setting a global variable called $current_user .

Multiple calls to wp_get_current_user() will immediately return if the global $current_user is already populated:

So looking over the list of variables you intended to set, I see no compelling need for any container variables on any of them. My advice would be to opt for explicit readability in your code wherever possible. Since WordPress supplies the function wp_get_current_user() whose purpose is to get that user, instead of creating a global $user and passing that around, make a call to the available function . It’s true that you cannot, for example, use the function call inside a string interpolation:

// Can't do this: echo "The user is user_login>"; 

. and so in cases where you had otherwise intended to create a global variable for the user’s login, set a local on one in your function.

function your_func() < $login = wp_get_current_user()->user_login; echo "The user is $login"; > 

As for setting a variable like $user_id which serves as a container for the ID property of the user object, since ID is indeed a property of the user object, it makes good logical sense to maintain that relationship in your code. Though this may be faster to type:

This makes explicit the source of the variable:

echo wp_get_current_user()->ID; // or even better, using the API function echo wp_get_current_user_id(); 

Finally, with regard to the $_SERVER array, it is already a PHP Superglobal array, available in all scopes without any extra effort needed. So instead of abstracting out one key from it in the form of:

I would opt to just make use of $_SERVER[‘REQUEST_URI’] directly in your own functions. If you find you need to use it several times in one function, for example, then feel free to create a local variable in the function:

But again, if you are using the superglobal value, your code will be more readable if it is used directly or the local variable is defined near where it is to be used (as opposed to a global variable defined in a separate include file whose value must be traced back to be understood).

Because I am not terribly familiar with WordPress’ API, I cannot say for certain if it provides an API function to retrieve the request URI. I would not be surprised however, if such a function already exists and is conventionally used in WP code.

You’re right, you shouldn’t use globals. One way around this is to put your theme code in a class and instantiate it.

The example below uses a singleton style class definition with the variables your theme template files might need and I think it achieves what your trying to do.

class My_Theme < public $favorites_array; public $user; public $user_id; public $user_name; public $uri; protected function __construct()< // TODO: put all your add_filter and add_action calls here $this->favorites_array = array(); $this->user = wp_get_current_user(); $this->user_name = $this->user->user_login; $this->user_id = get_current_user_id(); $this->uri = $_SERVER['REQUEST_URI']; > function get_instance() < static $instance; if( ! isset( $instance ) ) $instance = new self(); return $instance; >> My_Theme::get_instance(); 

and then in header.php you could have:

I should also point out that by the looks of the variables you have, you probably only need $favorites_array because the others can all be retrieved using WordPress functions and are just redundant.

Well, there is a lot of blog saying «Don’t use global» but in fact without explaining why. In all langages we have «global». And it’s not seems to be a problem. The only «problem» we can find is that, in a large code, it can be hard to find problem wuth global as they are (on many cases) in a different file (a huge C dev can have more than 100 files). In PHP, the code is, often, short.

What you must consider in fact, is using a naming convention to be able to detect quickly if a var is a global one or not. Eg naming them staring with «gl» or «glb», as yo want. This avoid forgetting to put «global» at beginning of function. Use session, fucntion parameter global and so on. Each as positive and negative point. No need to avoid using one of them.

Notice also if the value stay the same all over your code, maybe using a constant (DEFINE) can be another good option.

How to define global functions in PHP, In your php.ini file, search for the option auto_prepend_file and add your PHP file to that line, like this: `auto_prepend_file = …

How to create Globals Array

How do you create an array in GLOBALS for php?

for example, I want to do something like this:

$GLOBALS["chapter_names"] = array(); 

$GLOBALS["chapter_names"][$i] = $row -> CHAPTER_NAME; 

where $i is the index of the array

is this the optimal way to do things?

$GLOBALS["chapter_names"] = array(); foreach ($rows as &$row) < array_push($GLOBALS["chapter_names"], $row->CHAPTER_NAME); > 

Pretty much exactly as you gave it there. Except you don’t need to put an index of $i when you’re adding new stuff, unless it needs some specific index. You could just do it something like this:

$GLOBALS['chapter_names'] = array(); $GLOBALS['chapter_names'][] = $row -> CHAPTER_NAME; print_r($GLOBALS); 

$GLOBALS["chapter_names"] = array(); $row = new StdClass; $row->CHAPTER_NAME = 'test'; $i = 0; $GLOBALS["chapter_names"][$i] = $row -> CHAPTER_NAME; var_dump($GLOBALS); 

Amongst other things, the value is displayed.

["chapter_names"]=> array(1) < [0]=>string(4) "test" 

However, as you are probably aware, variables should only have as much scope as required, to prevent clashes and possible problems. Therefore, global variables should be avoided in most scenarios.

Don’t use $GLOBALS, it’s an outdated and quite dangerous practice. You can read about the registry pattern — it’s an OO solution to the problem. As for your example, it should be completely working.

PHP superglobals — Biggest Online Tutorials Library, PHP Server Side Programming Programming Introduction In addition to user defined variables, PHP populates the global namespace with a number …

PHP $GLOBALS

Introduction

$GLOBALS is an associative array of references to all globalle defined variables. Names of variables form keys and their contents are values of associative array.

$GLOBALS example

This example shows $GLOBALS array containing name and contents of global variables

Example

Output

This will produce following result. −

In following example, $var1 is defined in global namespace as well as a local variable inside function. Global variable is extracted from $GLOBALS array;

Example

 $var1="Hello World"; myfunction(); ?>

Output

This will produce following result. −

var1 in global namespace:Hello World var1 as local variable :Hello PHP

PHP $GLOBALS (super global) variable, Description $GLOBAL is a php super global variable which can be used instead of ‘global’ keyword to access variables from global scope, i.e. the …

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