Demystifying Functions

Functions are reusable blocks of code that perform specific tasks, promoting code organization and efficiency.

1. Built-in Function Example

Let's use the built-in `strlen` function to find the length of a string:

    $name = "Kristi";
    $nameLength = strlen($name);
    echo "The name '$name' has $nameLength characters.";
    

2. User-defined Function

Here's a function to calculate the area of a rectangle:

    function calculateRectangleArea($width, $height) {
        return $width * $height;
    }

    $area = calculateRectangleArea(5, 3);
    echo "
The area of a rectangle with width 5 and height 3 is $area square units.";
    

This function takes two arguments (width and height) and returns the calculated area.

Understanding Function Concepts

• Function definition: Defines the function name, arguments, and code block.
• Function call: Executes the function with specific arguments.
• Arguments: Values passed to the function for processing.
• Return values: Optional values returned by the function after execution.

Functions enable code reusability, modularity, and cleaner organization, making your code more readable and maintainable.