for Loop

for Statement

for is an entry control loop statement which executes the statements to a specified number of times. The for loop provides a more concise loop control structure. The general form of the for loop is:

Syntax:

for (initialization; test condition; increment)
{
  body of the loop;
}

statement-x;

Steps: -

1. Initialization of the loop control variable is done first.

2. The value of the loop-control variable is tested. If the condition is true, thebody of the loop 

    will be executed otherwise the loop will be terminated.        

3. When the body of the loop is executed, loop-control variable is incremented or updated wth 

     new value using assignment operator.

4. New value of the control variable is again tested to see whether it satisfies the test condition.

5. If the condition is satisfied (TRUE) means the body of the loop is again executed and this 

    process continues until the condition becomes FALSE.

    

Sample Program for printing numbers from 1 to 100

void main()
{
 int i;
 for(i=1;i<=100;i++) 
     printf(“\t%d”,i);
}
Note:- Here i is known as loop-control variable.

Features:-

1. More than one variable can be initialized at a time using comma operator.

            for(n=1,m=50;n<=m;n++,m--)

            {

                        printf(“%d”,m/n);

            }

2. The Test condition can have compound relations and the testing need not be limited to loop-   

    control variable.

            sum=0;

            for(i=1;i<10&&sum<100;i++)

            {

                        sum=sum+i;

                        printf(“%d”,sum);

            }

3. We can use assignment statements in initialization and increment sections.

            p=10;

q=6;

            for(x=(p+q)/2;x>=0;x=x/2)

            {

                        printf(“%d”,x);

            }

4. One or more sections can be omitted, but the semi-colons separating the sections must   

    remain.

            i=1;

            for(;i<=100;i++)

            {

                        printf(“%d”,i);

                        i++;

            }

    ** we can omit test condition if required, But this produces infinite loop.

5. Nesting of loops are allowed.

            for(i=2;i<=10;i++)

            {

               for(j=1;j<=10;j++)

               {

                  printf(“\t %d*%d=%d”,i,j,i*j);

               }

              printf(”\n”); 

            }

  * This program prints the Multiplication table.