The "pass by value" and "pass by reference" modes of parameter passing are supported by most languages.
C++ and Pascal directly support "by reference" parameters and C directly supports only "by value" parameters. In C, "pass by reference" is emulated by passing the address of a variable to a parameter defined as a pointer to type.
In JADE external function support, the C++ "by reference" parameter definition of the type& form and the C pointer parameter definition of the type* form are considered equivalent. As they are the same from the viewpoint of the caller, the address of a variable is passed to the called function in both forms.