To pad a number with leading zeros, a function is created here, which checks the number with its length and add leading zeros.
Example
You can try to run the following code to pad a number with leading zeros in JavaScript −
<!DOCTYPE html>
<html>
<body>
<script>
String.prototype.padFunction = function(padStr, len) {
var str = this;
while (str.length < len)
str = padStr + str;
return str;
}
var str = "2";
document.write(str.padFunction("0", 4));
var str = "8";
document.write("<br>"+str.padFunction("0", 5));
</script>
</body>
</html>Output
0002 00008