Question

How to access the PHP function of a class where the function is stored in variable?

For example:

$functionname = "say_hello";
$obj = new Class();
$obj -> $functionname();

Answer 1

if function name is stored in a variable check if it is exists and is callable like

   if ( method_exists( $product, $method ) ) {
print $product->$method(); // invoke the method
}

then check if it is callable

if ( is_callable( array( $product, $method) ) ) {
print $product->$method(); // invoke the method
}