what is coelscing operator

 The coalescing operator (also known as the null coalescing operator) ?? is a shorthand operator introduced in PHP 7.0. It provides a concise way to handle cases where a variable may be null or undefined, allowing you to specify a default value if the variable is null. The syntax for the coalescing operator is ??. Here's how it works:

php
$variable = $value ?? $default;

In this syntax:

• $value is the variable whose value you want to check.
• $default is the default value to use if $value is null or not set.

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

Here are some examples of using the coalescing operator:

php
$name = $username ?? 'Guest';

In this example, if $username is not null, $name will be assigned the value of $username. Otherwise, $name will be assigned the value 'Guest'.

php
$price = $product['price'] ?? 0;

Here, if $product['price'] exists and is not null, $price will be assigned that value. Otherwise, $price will be assigned 0 as the default value.

The coalescing operator is especially useful for handling cases where you want to provide a default value for variables that may be null or not set, without having to use longer conditional statements or ternary operators. It improves code readability and reduces boilerplate code for handling null values.