PHP If-Else Statements

The if and else statements in PHP are control structures that allow you to execute different blocks of code based on conditions. They are fundamental for decision-making in your PHP scripts.

Basic if Statement

The if statement checks a condition, and if it's true, it executes the block of code inside:

<?php
    $number = 10;
    if ($number > 5) {
        echo "The number is greater than 5.";
    }
    ?>

Output:

The number is greater than 5.

Using else for Alternate Conditions

The else statement runs a block of code when the if condition is false:

<?php
    $number = 3;
    if ($number > 5) {
        echo "The number is greater than 5.";
    } else {
        echo "The number is not greater than 5.";
    }
    ?>

Output:

The number is not greater than 5.

Adding elseif for Multiple Conditions

You can use elseif (short for "else if") to check additional conditions:

<?php
    $number = 8;
    if ($number > 10) {
        echo "The number is greater than 10.";
    } elseif ($number > 5) {
        echo "The number is greater than 5 but not greater than 10.";
    } else {
        echo "The number is 5 or less.";
    }
    ?>

Output:

The number is greater than 5 but not greater than 10.

Nesting if Statements

You can nest if statements to check complex conditions:

<?php
    $x = 7;
    $y = 15;
    if ($x > 5) {
        if ($y > 10) {
            echo "x is greater than 5 and y is greater than 10.";
        }
    }
    ?>

Output:

x is greater than 5 and y is greater than 10.

Using Logical Operators

Combine conditions with logical operators like and, or, and !:

<?php
    $age = 20;
    if ($age >= 18 && $age <= 25) {
        echo "You are eligible for this program.";
    }
    ?>

Output:

You are eligible for this program.

Next Steps

Practice creating decision-making structures in PHP. Understanding if, else, and elseif will help you build dynamic and interactive web applications. Now you can learn about loops!