What is the PHP Reference Assignment Operator (=&) and How Does It Work?

Understanding the Reference Assignment Operator (=&) in PHP

In the realm of PHP, the =& assignment operator plays a crucial role by establishing a reference relationship between variables. Unlike the regular assignment operator (=) that creates a copy, =& ensures that both variables point to the same underlying data.

This is particularly useful in scenarios where you want to work on a shared copy of an object or array. By using =&, you can make changes to one variable and observe those changes reflected in the other. This mechanism is often referred to as assignment by reference.

Is =& Deprecated?

Contrary to popular misconceptions, the =& operator is not deprecated in PHP. It remains the standard approach for establishing reference relationships.

Unique Syntax

While the =& operator is commonly written as equals-ampersand (=&), it can also be expressed as equals space ampersand (= &), often condensed into $x=&$y where it appears as if it's running into the target variable.

Practical Example

Consider the following code snippet:

$a = 3;
$b = &$a;
$a = 4;
print "$b"; // outputs 4

In this example, $b is assigned by reference to $a using =&. When $a is subsequently updated to the value 4, $b automatically reflects this change because it points to the same underlying data.

Additional Resources

For a more comprehensive understanding of assignment by reference in PHP, consult the following resources:

• [PHP Manual: Assign By Reference](https://www.php.net/manual/en/language.references.basics.html)
• [PHP Manual: References Part 1 - Introduction](https://www.php.net/manual/en/language.references.whatare.php)

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