There are three parameter modes for a procedure, given as follows:
IN — Refers to a constant value, which is assigned to this parameter from the calling environment. The IN parameter value cannot be modified within a procedure. It is a default mode.
OUT— Refers to a return value, which is passed from the procedure back to the calling environment.
IN OUT — Refers to a value, which is assigned from the calling environment to this parameter and a same or different value is passed back from the procedure to the calling environment using this parameter.
IN — Refers to a constant value, which is assigned to this parameter from the calling environment. The IN parameter value cannot be modified within a procedure. It is a default mode.
OUT— Refers to a return value, which is passed from the procedure back to the calling environment.
IN OUT — Refers to a value, which is assigned from the calling environment to this parameter and a same or different value is passed back from the procedure to the calling environment using this parameter.