Conditional Structures in PHP
In PHP, Conditional Structures are constructs that allow developers to execute specific blocks of code based on whether a condition is true or false. These structures are essential for decision-making within a program.
Definition
A Conditional Structure in PHP evaluates a given condition (usually a logical expression) and performs different actions depending on whether the condition evaluates to true or false.
Types of Conditional Structures in PHP
if Statement
Executes a block of code if the condition is true.
if (condition) {
// Code to be executed if condition is true
}
Example:
$number = 10;
if ($number > 5) {
echo "The number is greater than 5.";
}
if-else Statement
Provides an alternative block of code to execute if the condition is false.
if (condition) {
// Code to be executed if condition is true
} else {
// Code to be executed if condition is false
}
Example:
$number = 3;
if ($number > 5) {
echo "The number is greater than 5.";
} else {
echo "The number is not greater than 5.";
}
if-elseif-else Statement
Allows checking multiple conditions sequentially.
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 none of the conditions are true
}
Example:
$number = 5;
if ($number > 10) {
echo "The number is greater than 10.";
} elseif ($number == 5) {
echo "The number is exactly 5.";
} else {
echo "The number is less than 10 and not 5.";
}
Switch Statement
A more efficient way to evaluate a variable against multiple values.
switch (variable) {
case value1:
// Code to execute if variable equals value1
break;
case value2:
// Code to execute if variable equals value2
break;
default:
// Code to execute if no cases match
}
Example:
$day = "Wednesday";
switch ($day) {
case "Monday":
echo "Start of the work week!";
break;
case "Wednesday":
echo "Midweek day.";
break;
case "Friday":
echo "Almost the weekend!";
break;
default:
echo "Just another day.";
}
Tags:
php