? PHP Variable Functions

? Quick Overview

PHP variable functions allow a variable to hold the name of a function and call it dynamically. This enables flexible and dynamic execution of functions at runtime.

? Key Concepts

• Function names can be stored in variables
• Variables can dynamically invoke functions
• Useful for callbacks and dynamic logic

? Syntax / Theory

// Store function name in a variable and call it
$functionName = 'someFunction';
$functionName();

? Example 1: Basic Variable Function

Call a function dynamically using a variable:

// Define a simple function
function sayHello() {
echo "Hello, World!";
}

// Assign function name to variable and call it
$func = 'sayHello';
$func();

? Example 2: Passing Arguments to Variable Functions

You can also pass arguments to functions via variable functions:

// Function with parameter
function greet($name) {
echo "Hello, $name!";
}

// Call function dynamically with argument
$func = 'greet';
$func('Alice');

? Example 3: Multiple Functions

// Define multiple operations
function add($a, $b) {
return $a + $b;
}

function multiply($a, $b) {
return $a * $b;
}

// Choose operation dynamically
$operation = 'multiply';
echo $operation(5, 10);

? Interactive Concept

Think of variable functions like a remote control — the button you press (variable value) decides which action (function) runs.

? Use Cases

• Callback systems
• Routing logic
• Plugin or hook architectures