If Statement

Code Fragment can be executed only if a certain condition is met.

Syntax

if(condition) { // Code to execute if condition is met. }

condition has a boolean type (true or false).

Basic Example

<?php if (true) { echo "a"; } if (false) { echo "b"; } $varName = true; if ($varName) { echo "c"; }

Output:

ac

if condition is true - execute the code inside if fragment.

Comparison Operators

Operator	Description	Examples	Result
==	Equal to	5 == 5	true
		4 == 5	false
		'4' == 4	true
===	Identical to	5 === 5	true
		4 === 5	false
		'3' === 3	false
!=	Not equal to	7 != 5	true
		4 != 4	false
		true != false	true
!==	Not Identical to	7 != 5	true
		4 !== 4	false
		5 !== '5'	true
>	Greater than	5 > 0	true
		5 > 5	false
		10 > 0	true
>=	Greater than or equal to	3 >= 3	true
		5 >= 4	true
		3 >= 5	false
<	Less than	3 < 5	true
		5 < 6	true
		5 < 5	false
<=	Less than or equal to	2 <= 0	false
		5 <= 5	true
		5 < 1	false

Let's create a program that uses comparisons operators.

Determine whether person is adult (age >= 21) or child (age < 13) depending on his/her age.

<?php $age = 25; if ($age >= 21) { echo "Adult"; } if ($age < 13) { echo "Child"; }

Output:

Adult

Since age is greater than 21, line 5 executes.

Because age is not less than 13, line 9 is not executed.