List of functions

I want to create a list of functions that can be run by a numerical variable without if statements.

I have tried to create an array and then store functions in that array as follows

$funcs = array();
$funcs[4] = function() {
//function code in here
}

and then to run the function I will do the following

$num = 4;
$funcs$num;

However, when I run the code I get the following error

Parse error: syntax error, unexpected T_FUNCTION

Does anyone know where I am going wrong or if there is an alternative way of achieving the same goal?

Any help would be great.