Conditional Statements in PHP
Introduction
Conditional statements are an essential part of any programming language. They allow you to execute different code blocks based on certain conditions. In PHP, there are several types of conditional statements:
- if statement
- if-else statement
- if-elseif-else statement
- switch statement
if Statement
The if statement executes a block of code if a specified condition is true. The syntax is as follows:
if (condition) {
// code to be executed if condition is true
}
Example:
<?php
$a = 10;
if ($a > 5) {
echo "a is greater than 5";
}
?>
if-else Statement
The if-else statement executes one block of code if a condition is true and another block of code if the condition is false. The syntax is as follows:
if (condition) {
// code to be executed if condition is true
} else {
// code to be executed if condition is false
}
Example:
<?php
$a = 10;
if ($a > 15) {
echo "a is greater than 15";
} else {
echo "a is not greater than 15";
}
?>
if-elseif-else Statement
The if-elseif-else statement allows you to test multiple conditions and execute different code blocks based on which condition is true. The syntax is as follows:
if (condition1) {
// code to be executed if condition1 is true
} elseif (condition2) {
// code to be executed if condition2 is true
} else {
// code to be executed if neither condition1 nor condition2 is true
}
Example:
<?php
$a = 10;
if ($a > 15) {
echo "a is greater than 15";
} elseif ($a == 10) {
echo "a is equal to 10";
} else {
echo "a is less than 10";
}
?>
switch Statement
The switch statement is used to perform different actions based on different conditions. It is often used as an alternative to the if-elseif-else statement. The syntax is as follows:
switch (expression) {
case value1:
// code to be executed if expression == value1
break;
case value2:
// code to be executed if expression == value2
break;
default:
// code to be executed if expression doesn't match any case
}
Example:
<?php
$day = "Tuesday";
switch ($day) {
case "Monday":
echo "Today is Monday";
break;
case "Tuesday":
echo "Today is Tuesday";
break;
case "Wednesday":
echo "Today is Wednesday";
break;
default:
echo "Today is not Monday, Tuesday or Wednesday";
}
?>