PHP Magic - the Null Coalescing Operator (??) - return the value if the give variable is NULL

The PHP Null Coalescing Operator (??) is a convenient way to handle situations where a variable or an array element might be null or undefined. It provides a concise syntax for choosing a default value when the variable or array element is null or does not exist.

Syntax:

$variable = $value ?? $default;

Explanation:

If $value is not null, $variable will be assigned the value of $value.

If $value is null, $variable will be assigned the value of $default.

Example Usage:

1. Using with Variables:

$username = $input_username ?? 'Guest';

In this example, if $input_username is set and not null, $username will be assigned its value. Otherwise, $username will be assigned the default value 'Guest'.

2. Using with Array Elements:

$value = $array['key'] ?? $default;

Here, if the key 'key' exists in $array and its value is not null, $value will be assigned that value. If the key doesn't exist or its value is null, $value will be assigned the default value $default.

Notes:

The null coalescing operator was introduced in PHP 7.0, so make sure you are using PHP 7.0 or later versions.

It's especially useful for avoiding "undefined variable" or "undefined index" notices in your code.

The null coalescing operator is a handy tool for writing clean and concise PHP code, especially when dealing with potentially null values.