Page 287 - Computer_Science_F5

Computer Science Note: There are two ways to call functions, which are function call by value (pass
by value) and function call by reference (pass by reference).
(a) Call by value involves copying the values of actual parameters into the
formal parameters.
FOR ONLINE READING ONLY
(b) Call by reference involves copying the address of the arguments into
actual parameters within the function.

Program examples 30 and 31 demonstrate call by value and call by reference. Program
Example 4.29 demonstrates a C++ program that finds cube of the number. The output
is shown in Figure 4.58.

Program Example 4.29:

Finding the cube of the number using function

#include<iostream>
using namespace std;
int cube(int x)
{
x=x*x*x;
return x;

}
int main()
{
int a;
cout<<”Enter number to find its cube “;
cin>>a;
cout<<”Cube of “<<a<<” is “<<cube(a);// call by value
}

Output:

Figure 4.58: Output of the program

You can use the following program example to learn on program that interchanges
values entered by a user. The following Program Example 4.30 demonstrates a
C++ program that interchanges value entered by the user. The output is shown in
Figure 4.59.

278
for Advanced Secondary Schools

Computer Science Form 5.indd 278 23/07/2024 12:34