PHP Conditions

Conditions let your program choose what to do, for example show "Pass" or "Fail" depending on marks.

Comparison Operators

A comparison gives true or false.

Operator	Meaning	Example (`$a = 5`)	Result
`==`	Equal value	`$a == "5"`	true
`===`	Equal value and same type	`$a === "5"`	false
`!=`	Not equal	`$a != 3`	true
`!==`	Not equal or different type	`$a !== 5`	false
`>`	Greater than	`$a > 2`	true
`<`	Less than	`$a < 2`	false
`>=`	Greater or equal	`$a >= 5`	true
`<=`	Less or equal	`$a <= 4`	false

Prefer === and !==. They check the type too, so they avoid surprises when a form sends the number "5" as text.

Logical Operators

&& (and): true when both sides are true
|| (or): true when at least one side is true
! (not): turns true into false and false into true

if, elseif and else

Example

php

<?php
$marks = 72;

if ($marks >= 80) {
    echo "Grade A";
} elseif ($marks >= 60) {
    echo "Grade B";
} elseif ($marks >= 40) {
    echo "Grade C";
} else {
    echo "Fail";
}

Output

Grade B

PHP checks the conditions from top to bottom and runs only the first block whose condition is true.

Combining Conditions

Example

php

<?php
$age = 20;
$hasCnic = true;

if ($age >= 18 && $hasCnic) {
    echo "You can register for the course online.";
} else {
    echo "Please visit the institute with a guardian.";
}

Output

You can register for the course online.

The Ternary Operator

A short form of if/else for simple choices:

Example

php

<?php
$stock = 0;
echo $stock > 0 ? "In stock" : "Out of stock";

Output

Out of stock

The null coalescing operator ?? gives a default when a value is missing or null:

Example

php

<?php
$username = null;
echo "Hello, " . ($username ?? "Guest");

Output

Hello, Guest

switch

switch compares one value against many cases:

Example

php

<?php
$day = "Fri";

switch ($day) {
    case "Sat":
    case "Sun":
        echo "Weekend classes at 10 am";
        break;
    case "Fri":
        echo "Short day: classes end at 12";
        break;
    default:
        echo "Regular classes at 4 pm";
}

Output

Short day: classes end at 12

Do not forget break. Without it PHP continues into the next case.

match (PHP 8)

match is a cleaner, safer version of switch. It returns a value, uses strict comparison (===), and needs no break.

Example

php

<?php
$code = 404;

$message = match ($code) {
    200 => "OK",
    301, 302 => "Moved",
    404 => "Page not found",
    500 => "Server error",
    default => "Unknown status",
};

echo $message;

Output

Page not found

Exercise

What is the result of 10 === "10" in PHP?

truefalseAn errornull