Unary Operator

A unary operator is an operator that operates on a single operand. It performs an operation on the value of the operand. PHP supports several unary operators, including the following:

  • Post increment operator $a++

  • Pre increment operator ++$a

  • Post decrement operator $a--

  • Pre decrement operator --$a

  • Negative operator -$a (produces the opposite of the value)

  • Logical Not operator !$a

  • Bitwise Not operator ~$a

  • Noscream operator @$a

The four first operators change the underlying value and also return the value. The three last operators only return the changed value, leaving the original value unchanged.

<?php

$a = 10;
print -$a;  // -10, $a unchanged
print $a;   // 10
print ++$a; // 10, $a changed
print $a;   // 11

?>

Related : Ternary Operator