Function is a code block that executes certain task.


Void Example

A void function doesn't return any value.



Returning Result

Via the return keyword a result can be returned.

Let's have an example in which rectangle's area is calculated by passing arguments about it's sides.



There are couple of things to mark:

  • A functions is defined at lines 7 - 9. It accepts two arguments - widthArg and heightArg both of type double.
  • The function calcRectangleArea returns a double result.
  • calcRectangleArea is called at line 3.
  • It's returned value is set in the variable area.

Common Exceptions

Return Mismatch

If a function returns value different than the specified type, it causes an exception.

In this case 5 should be replaced with string value.

Arguments Type Mismatch

Atline 6 the function expects argument of type int.

At line 3 an argument of string type is passed.

The passed argument at line 3 should be replaced with integer value.

Arguments Count Mismatch

The function calcTrapezoidArea expects 3 arguments but only 2 are passed to it.