This loop is used when we have to execute a part of code in finite times.
for (Expression 1; Expression 2; Expression 3)
{
Loop body
}
Expression 1: Setting a loop counter to an initial value.
Expression 2: Testing the loop counter to determine whether its value has reached the number of repetitions desired.
Expression 3:(‘loop counter or index variable) Increasing the value of loop counter each time the program segment within the loop has been executed.
Flow Chart of for loop: same as while loop
#include<stdio.h>
#include<conio.h>
int main( )
{
int p, n, count ;
float r, si ;
for(count = 1 ;count <= 3;count++)
{
printf ( "Enter values of p, n, and r: \n" ) ;
scanf ( "%d %d %f", &p, &n, &r ) ;
si = p * n * r / 100 ;
printf ( "Simple Interest = Rs.%f\n", si ) ;
}
getch();
return 0;
}
Enter values of p, n, and r:
500
6
6
Simple Interest = Rs.180.000000
When the for statement is executed for the first time, the value of count is set to an initial value 1.
Now the condition count <= 3 is tested. Since count is 1 the condition is satisfied and the body of the loop is executed for the first time.
Upon reaching the closing brace of for, control is sent back to the for statement, where the value of count gets incremented by 1.
Again the test is performed to check whether the new value of count exceeds 3.
If the value of count is still within the range 1 to 3, the statements within the braces of for are executed again.
The body of the for loop continues to get executed till count doesn’t exceed the final value 3.
When count reaches the value 4 the control exits from the loop and is transferred to the statement (if any) immediately after the body of for.
#include<stdio.h>
#include<conio.h>
int main ( )
{
int r, c, sum ;
for ( r = 1 ; r <= 3 ; r++ ) /* outer loop */
{
for ( c = 1 ; c <= 3 ; c++ ) /* inner loop */
{
sum = r + c ;
printf ( "r = %d c = %d sum = %d\n", r, c, sum ) ;
}
}
getch();
}
r = 1 c = 1 sum = 2
r = 1 c = 2 sum = 3
r = 1 c = 3 sum = 4
r = 2 c = 1 sum = 3
r = 2 c = 2 sum = 4
r = 2 c = 3 sum = 5
r = 3 c = 1 sum = 4
r = 3 c = 2 sum = 5
r = 3 c = 3 sum = 6
Note: for loop can occur within a while loop, or a while within a for loop.