Difference between Elvis, and Null Coalescing Operators

In this article, I will show you the differences between popular operators in PHP. I hope my short post will help you understand operators better.

Elvis operator

The elvis operator (?:) is actually the name used for the abbreviated ternary operator (which was introduced in PHP 5.3). The elvis operator is a shorthand operator for the ternary operator. We can also say that it is a modified form of the ternary operator. To understand the Elvis operator in PHP, we need to know the ternary operator and how it works. The ternary operator is a conditional operator used to perform a simple comparison or check of a condition having simple statements. It is a shorter version of the if-else statement.

It has the following syntax:

$var ?: false;

This is equivalent to:

$var ? $var : false;

and

if ($var) {
    $result = $var;
} else {
    $result = false;
}

Null Coalescing Operator

The null coalescing operator (??) was introduced in PHP 7. The null coalescing operator checks whether the specified variable is null or not, and returns a non-null value from the value pair. The output of the null coalescing operator depends on whether the variable is null.

It has the following syntax:

$var ?? false;

This is equivalent to:

isset($var) ? $var : false;

and

if (isset($var)) {
    $result = $var;
} else {
    $result = false;
}