Page 252 - Computer_Science_F5

Program Example 4.9:

Global variable declaration

int x=5, y=2; Chapter Four: Object oriented programming with C++
FOR ONLINE READING ONLY
main()
{
fun();
}
fun()
{
int sum;
sum = x + y;
}

Variables x and y in this program are global variables because they have been
declared before the main function, main(), and are also used within the function.

(c) Static variables
Static variables are types of variables declared only once within a function, but they
are used in a whole program. The keyword “static” is used to declare static variables.
For Example:
static int i, j;
static float a, b;
static char name;

The following is a Program Example 4.10 of a C++ program that finds the area of
the rectangle. The output is shown in Figure 4.24.

Program Example 4.10:

Finding the area of the rectangle

#include<iostream>
using namespace std;
int main()
{
int l, w; //Declaration of length (l) and width (w)as integers data type
double area; //Declaration of area as double data type
cout<<”Enter a length in metres: “;
cin>>l; //Read value of length entered by the user
cout<<”Enter a width in metres: “;
cin>>w; //Read value of width entered by the user
area=l*w;
cout<<”The area of the rectangle is “<<area<<”square metres”<<endl;
return 0;
}

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Student’s Book Form Five

Computer Science Form 5.indd 243 23/07/2024 12:33