Expressions And Operators: Ternary

The ternary operator ? : is a shorthand for if statements. It is an expression, so it evaluates to a value. For example:

$days_in_feb = is_leap_year($year) ? 29 : 28;

It takes three operands e1 ? e2 : e3. If e1 evaluates to a truthy value, then the result is the evaluation of e2. Otherwise the result is the evaluation of e3.

Elvis Operator

There is also a two operand version ?:, sometimes called the "elvis operator". This results in the first operand if it evaluates to a truthy value. For example:

$x = foo() ?: bar();

// Is equivalent to:
$tmp = foo();
$x = $tmp ? $tmp : bar();