Strict Comparison

Strict comparison is a comparison operator or a control structure that checks not only the value but also the type of the value. In other words, it does not apply any type-juggling to the values before processing.

Here are the strict operators : == may be replaced with ===, != may be replaced with !==, switch may be replaced with match, in_array() with the third parameter strict set to true.

<?php

//true
var_dump(1 == "1");
//false
var_dump(1 === "1");

//true
var_dump(null == 0);
//false
var_dump(null === 0);

?>

Documentation

See also Strict vs. Loose Comparisons in PHP

Related : Switch, Match, Relaxed Comparison