Identity
True if only operands are of the same data type and the same value.
/**
* Identical operator
*/
$x1 = 'xn--google.com';
$x2 = 'google.com';
var_dump(stripos($x1, 'xn--') === 0); // true - Correct
var_dump(stripos($x2, 'xn--') == 0); // true - Incorrect
Confusion
It's easy to confuse the assignment operator = for the comparison operator ==
/**
* Comparition operator, prone to error
*/
$a = 10;
$b = 9;
var_dump($a == 10); // true
var_dump(10 == $a); // true, better
if ($b = 10) echo $b; // 10 - Incorrect
Inequality
While the process is clear for numbers, things change a bit for other data types.
/**
* Comparing strings
*
* D > C, a > A
*
* ASCII value of a (97)
* ASCII value of A (65)
*/
var_dump("ABC" > "ABD"); // false
var_dump("apple" > "Apple"); // true
Last update: 432 days ago