PHP – Decision Making

In PHP, decision making refers to the process of controlling the flow of your program based on certain conditions. PHP provides several conditional statements to make decisions in your code, including if, else, elseif, and switch. These statements help you execute different blocks of code depending on whether specific conditions are met.

Here are some code examples illustrating decision making in PHP:

1. The if statement:

The if statement is the most basic form of decision making in PHP. It checks a condition and executes a block of code if the condition is true.

$age = 18;
if ($age >= 18) {
    echo "You are an adult.";
}

In this example, the message “You are an adult.” will be printed if the value of $age is greater than or equal to 18.

2. The else statement:

The else statement allows you to execute an alternative block of code if the condition in the if statement is false.

$age = 16;
if ($age >= 18) {
    echo "You are an adult.";
} else {
    echo "You are not an adult.";
}

In this example, the message “You are not an adult.” will be printed if the value of $age is less than 18.

3. The elseif statement:

The elseif statement allows you to test multiple conditions and execute the first block of code whose condition is true.

$grade = 85;
if ($grade >= 90) {
    echo "You got an A.";
} elseif ($grade >= 80) {
    echo "You got a B.";
} elseif ($grade >= 70) {
    echo "You got a C.";
} else {
    echo "You got a D or below.";
}

In this example, the message “You got a B.” will be printed since the value of $grade is 85.

4. The switch statement:

The switch statement is an alternative to using multiple if and elseif statements when you need to test a variable against multiple values.

$weekday = "Friday";
switch ($weekday) {
    case "Monday":
        echo "Today is Monday.";
        break;
    case "Tuesday":
        echo "Today is Tuesday.";
        break;
    case "Wednesday":
        echo "Today is Wednesday.";
        break;
    case "Thursday":
        echo "Today is Thursday.";
        break;
    case "Friday":
        echo "Today is Friday.";
        break;
    case "Saturday":
        echo "Today is Saturday.";
        break;
    case "Sunday":
        echo "Today is Sunday.";
        break;
    default:
        echo "Invalid weekday.";
}

In this example, the message “Today is Friday.” will be printed since the value of $weekday is “Friday”.

These are the basic decision-making statements in PHP, which allow you to control the flow of your program and execute different blocks of code based on specific conditions.