while and do-while Loops Example: Result: Do-while loop: Syntax: Example: Result:
Two additional repeat loops are available in JavaScript. The while loop tests the supplied condition and continues to execute until it is met. Here is the syntax for it.
Syntax:
while (condition){
statement(s)
}
<html>
<body>
<script type="text/javascript">
var i=0;
while (i<=10)
{
document.write("The number is " + i);
document.write("<br />");
i=i+1;
}
</script>
</body>
</html>
The number is 0
The number is 1
The number is 2
The number is 3
The number is 4
The number is 5
The number is 6
The number is 7
The number is 8
The number is 9
The number is 10
The primary difference between these while and do-while loop is that the "do-while loop" will always execute one time whether the condition is true or not whereas the "while loop" will only execute if the condition is true.
do{
statements
} while (condition)
<html>
<body>
<script type="text/javascript">
var i=0;
do
{
document.write("The number is " + i);
document.write("<br />");
i=i+1;
}
while (i<0);
</script>
</body>
</html>
The number is 0