Conditionals in PHP

Conditionals in PHP:

Conditionals are fundamental to any programming language, enabling you to make decisions within your code. PHP offers a range of conditional statements to help control the flow of your script based on various conditions. In this blog, we’ll delve into the core conditional statements in PHP: ‘if‘, ‘else‘, ‘elseif‘ statements, ‘switch‘ case statements, and logical operators.

If, Else, and Elseif Statements

The ‘if‘ statement is used to execute a block of code if a specified condition is true. If the condition is false, you can use ‘else‘ to execute an alternative block of code. The ‘elseif‘ statement allows you to test multiple conditions.

If Statement

The ‘if‘ statement evaluates an expression. If the expression is true, the block of code within the ‘if‘ statement is executed.

<?php
$number = 10;

if ($number > 0) {
    echo "The number is positive.";
}
?>

Else Statement

The ‘else‘ statement executes a block of code if the condition in the ‘if‘ statement is false.

<?php
$number = -10;

if ($number > 0) {
    echo "The number is positive.";
} else {
    echo "The number is not positive.";
}
?>

Elseif Statement

The ‘elseif‘ statement allows you to test multiple conditions. It executes a block of code if the previous conditions are false but the 'elseif' condition is true.

<?php
$number = 0;

if ($number > 0) {
    echo "The number is positive.";
} elseif ($number < 0) {
    echo "The number is negative.";
} else {
    echo "The number is zero.";
}
?>

Switch Case Statements

The ‘switch‘ statement is an alternative to using multiple ‘if...elseif‘ statements. It is used to perform different actions based on different conditions.

Syntax of Switch Case

<?php
$color = "red";

switch ($color) {
    case "red":
        echo "The color is red.";
        break;
    case "blue":
        echo "The color is blue.";
        break;
    case "green":
        echo "The color is green.";
        break;
    default:
        echo "The color is neither red, blue, nor green.";
}
?>

In the example above, the ‘switch‘ statement evaluates the value of ‘$color‘. It then matches the value against each ‘case‘. If a match is found, the corresponding block of code is executed. The ‘break‘ statement is used to prevent the code from running into the next case. If no match is found, the ‘default‘ block is executed.

Logical Operators

Logical operators are used to combine multiple conditions. The most common logical operators in PHP are ‘&&‘ (AND), ‘||‘ (OR), and ‘!‘ (NOT).

AND (&&) Operator

The ‘&&‘ operator returns true if both conditions are true.

<?php
$age = 25;
$hasLicense = true;

if ($age >= 18 && $hasLicense) {
    echo "You are eligible to drive.";
} else {
    echo "You are not eligible to drive.";
}
?>

In this example, the message “You are eligible to drive.” is displayed only if both ‘$age‘ is 18 or older and ‘$hasLicense‘ is true.

OR (||) Operator

The ‘||‘ operator returns true if at least one of the conditions is true.

<?php
$isWeekend = true;
$isHoliday = false;

if ($isWeekend || $isHoliday) {
    echo "You can relax today.";
} else {
    echo "It's a working day.";
}
?>

Here, the message “You can relax today.” is displayed if either ‘$isWeekend‘ is true or ‘$isHoliday‘ is true.

NOT (!) Operator

The ‘!‘ operator returns true if the condition is false.

<?php
$isRaining = false;

if (!$isRaining) {
    echo "You can go for a walk.";
} else {
    echo "You should stay indoors.";
}
?>

In this example, the message “You can go for a walk.” is displayed because ‘$isRaining‘ is false.

Combining Logical Operators

You can combine logical operators to form complex conditions.

?php
$age = 20;
$isStudent = true;

if (($age < 18 || $age > 65) && $isStudent) {
    echo "You are eligible for a student discount.";
} else {
    echo "You are not eligible for a student discount.";
}
?>

In this example, the message “You are eligible for a student discount.” is displayed if the person is either younger than 18 or older than 65 and is also a student.

Conclusion

Understanding conditionals in PHP is crucial for making decisions and controlling the flow of your code. By mastering ‘if‘, ‘else‘, ‘elseif‘ statements, ‘switch‘ case statements, and logical operators, you’ll be able to write more flexible and dynamic scripts. As you continue to practice and apply these concepts, you’ll gain confidence in handling complex conditions and enhancing the functionality of your PHP applications.