Provides programmers with the ability to hide procedural details Process abstraction allows us to be concerned only with a procedure’s interfaceE. g given a procedure sort we don’t need to know the body of sort in order to use it.
Data abstraction: allows the use of sophisticated data types without knowing how such types are implemented. Again, the aims are to separate concerns and to promote reusability and maintainability of programs.
By position: The binding of actual parameters to formal parameters is by their order of appearance: the first actual parameter is bound to the first formal parameter and so forth. x=foo(3, 0); Safe and effective.
Keyword: The names of the formal and actual parameters are used Advantage: Parameters can appear in any order, thereby avoiding parameter correspondence errors. Disadvantage: User must know the formal parameters’ names.
what is in(put) mode in referance to Parameter Passing Methods