Iteration Statements (Loop Statements)

Iteration statements are also called loop statements.
Iteration or loop allows a set of instructions to be executed repeatedly based on some condition.
The statements which appear in the source code only once but execute many times, such kind of statements are called loops.
It has initialization expression, condition expression and updates expression.
Loop statements are divided into two:
1. Entry Controlled Loop
2. Exit Controlled Loop

Entry Controlled Loop

In the entry, controlled loop condition expression will be evaluated first.
If it is true the body of the loop will be executed and repeats until the condition becomes true.

In an exit controlled loop, first, the body of the loop will be executed without checking the condition.
The condition expression will be evaluated after the execution of loop body once.
Loops can be again classified as
1. for loop
2. while loop
3. do-while loop

     for (Initialization Expression; condition Expression; Update Expression){
          body-of the-loop;
     }

First the initialization expression will be evaluated first.
Then checks the condition expression.
If the condition expression is true, the body of the loop will be executed and update the update expession.
Then checks the condition of update expression. If it is true repeat steps two and three.If it is false exit from the loop.

C PROGRAM TO PRINT NUMBERS FROM 1 TO 10

      #include
      main()
      {
        for(i=0;i<10;i++){ 
          printf("%d",i);
        }
      }

In the main function, the execution of the program starts.
First executes initialization expression,ie set i=0.
Then evaluates condition expression i<10.ie 0<10 ,it is true, so jump to the body of the loop.
In the body of the loop it has given to the print value of i.ie the current value of i is 0, so print 0.
Next, evaluate condition expession.here increment the value of i.ie i=i+1,ie i=0+1=1 .
Again evaluates condition expression i<10.ie 1<10 and loop body works.
Repeat steps 3,4,5,6 until the condition becomes false.
When i=10, the condition expression will not satisfy. ie 10<10 is false.so exit from the loop.

C program to print numbers up to a given limit.
C program to print even numbers up to a given limit.
C program to print odd numbers up to a given limit.
C program to find the sum of even numbers and sum of odd numbers up to a given limit.
C program to print factorial of a number.
C program to print the Fibonacci series up to a limit.
C program to check whether a number is prime or not.
C program to check whether a number is a palindrome or not.
C program to find the sum of natural numbers up to a limit.