What are the potential pitfalls of not properly defining variables within PHP functions?

Not properly defining variables within PHP functions can lead to unexpected behavior, errors, and security vulnerabilities. It's important to explicitly declare variables within functions to ensure they are properly scoped and initialized. This can prevent conflicts with variables outside the function and make the code more readable and maintainable. 

// Incorrect way of defining variables within a PHP function
function calculateSum($num1, $num2) {
    $sum = $num1 + $num2;
    return $sum;
}

// Correct way of defining variables within a PHP function
function calculateSum($num1, $num2) {
    $sum = 0; // Initialize the variable
    $sum = $num1 + $num2;
    return $sum;
}

Keywords

undefined variables scope function errors debugging

Related Questions