Introduction to Loops in JavaScript: Iteration and Examples

Loops provide a quick and effortless way to repeat certain operations. Let us see some of the important loops in JS

1. for statement
2. while statement
3. do...while statement
4. For of loop
5. For in Loop

For Loop

Syntax

 for ([initialization]; [condition]; [final-expression])
   statement

• Initialization - An expression to initialize counter variable
• condition - An expression to evaluate every loop iteration
• final-expression - An expression to update the counter variable

Example:

    for (var i = 0; i < 9; i++) 
    {
            console.log(i);
            // more statements
    }

While Loop

Syntax

 while (condition) { statement} 

Example:

    var n = 0;
    var x = 0;
    while (n < 3) {
         n++;
         x += n;
 }

Do... While Loop

Syntax

do statement while condition 

Example:

 var i = 0;
    do {
     i += 1;
     console.log(i);
    } while (i<5); 

Assignment 1

• Write a program to draw a chessboard of size 8X8.
• Each line of the chessboard should have a + and a - . + indicates black cell and - indicates a white cell on the chess board.
• Draw a border with * on all four sides.
• You can try this using different loops.