What are the implications of not properly initializing variables and not thoroughly testing PHP scripts that involve array manipulation?

Not properly initializing variables and not thoroughly testing PHP scripts that involve array manipulation can lead to unexpected behavior, errors, and security vulnerabilities. To solve this issue, always initialize variables before using them and thoroughly test your scripts with various input scenarios to ensure they handle arrays correctly.

// Initializing variables before using them
$myArray = array();

// Thoroughly testing array manipulation
$myArray = [1, 2, 3];
array_push($myArray, 4);
print_r($myArray);