What are the potential pitfalls of using global variables in PHP functions, according to the discussion?

Using global variables in PHP functions can lead to code that is difficult to debug, maintain, and test. It can create dependencies between functions that are not immediately apparent, making it harder to understand the flow of data in your code. To avoid these pitfalls, it is recommended to pass variables as parameters to functions instead of relying on global scope.

// Avoid using global variables in PHP functions by passing variables as parameters

// Bad practice using global variable
$globalVar = 10;

function badFunction(){
    global $globalVar;
    echo $globalVar;
}

badFunction(); // Output: 10

// Good practice passing variables as parameters
$globalVar = 10;

function goodFunction($var){
    echo $var;
}

goodFunction($globalVar); // Output: 10