Chapter 5.2, Problem 10STE

Program Plan Intro

void Functions:

• A function must either return a single or no value at all.
• A function that would not return a value is termed as “void” function.
• The “void” function is been defined in same way as function that would return a value.
• It implements only subtask for complete problem.
• If a “void” function is called, formal parameters are substituted with arguments.
• The statements in function body are executed.
• The “return” statement specifies value that is been returned.

Call-by-Reference:

• It is a method for substituting arguments.
• The corresponding argument is substituted for formal parameter.
• The argument for a function call might be a variable.
• This argument variable is substituted for formal parameter.
• It is similar to copying of argument variables into function definition body in place of formal parameter.
• The code in function body is executed once argument is substituted.
• This code can change argument variable value.
• The ampersand sign (&) is attached to end of type name in formal parameter list in both function declaration as well as function header definition.

Call-by-value:

• It copies the actual value of an argument into function’s formal parameter.
• The changes made to parameter inside function have no effect on argument.
• This method is used in default in programs.
• The code within a function could not alter arguments used for calling function.