What is the difference between call_user_func() and call_user_func_array() in PHP?

call_user_func() and call_user_func_array() are two PHP functions that are used to dynamically call a function by its name or reference.

The main difference between the two functions is in the way they pass arguments to the function being called:

1. call_user_func() expects the function’s arguments to be passed as individual parameters after the function name or reference. For example:

$result = call_user_func('my_function', $arg1, $arg2, $arg3);

2. call_user_func_array() expects the function’s arguments to be passed as an array after the function name or reference. For example:

$args = array($arg1, $arg2, $arg3);
$result = call_user_func_array('my_function', $args);

In other words, call_user_func_array() allows you to pass a variable number of arguments to the function being called, whereas call_user_func() requires you to explicitly pass each argument as a separate parameter.

It’s worth noting that call_user_func_array() is generally slower than call_user_func() because it has to create an array of arguments and then pass that to the function being called. However, if you need to call a function with a variable number of arguments, call_user_func_array() is the only option.