What are the potential security risks of using array_merge function without understanding its purpose in PHP?

Using the array_merge function without understanding its purpose in PHP can lead to potential security risks such as unintended data overwriting, unexpected behavior, and vulnerability to injection attacks. To mitigate these risks, it is crucial to understand how array_merge works and properly sanitize input data before merging arrays.

// Example of how to safely use array_merge by sanitizing input data
$array1 = [1, 2, 3];
$array2 = [4, 5, 6];

// Sanitize input data before merging arrays
$sanitizedArray1 = array_map('intval', $array1);
$sanitizedArray2 = array_map('intval', $array2);

// Merge sanitized arrays
$mergedArray = array_merge($sanitizedArray1, $sanitizedArray2);

print_r($mergedArray);