If, Else, Elseif in

About If, Else, Elseif

Conditional statements using if, elseif, and else are a fundamental parts of program control flow. The if statement evaluates an expression, and if true, will execute the code branch.

<?php

if ($expression) {
    // .. executed if $expression is true
}

If the expression is not a boolean value, the evaluation determines the value's "truthiness" or "not falsiness". In PHP, the following values are considered equal to false:

• boolean false
• integer 0
• float 0.0 and -0.0
• an empty array []
• an empty string "" or a numeric string "0"
• null

All other values are considered true.

Responding to multiple conditions

Following an if statement, you may chain multiple conditions using elseif and else.

<?php

if ($value === 0) {
    // .. do something
} elseif ($value === 1) {
    // .. do something else
} else {
    // ,, do this if nothing else
}

Only one conditional statement evaluated as true will be executed. So if multiple conditions may evaluate to true, the order they are written is important.

<?php

if (true) {
    // .. always do something
} elseif (true)
    // .. will never be executed
} else {
    // .. will never be executed
}