Show a leading zero if a number is less than 10

javascript math numbers digits

Nicekiwi · Nov 11, 2011 · Viewed 104.8k times · Source

Possible Duplicate:
JavaScript equivalent to printf/string.format
How can I create a Zerofilled value using JavaScript?

I have a number in a variable:

var number = 5;

I need that number to be output as 05:

alert(number); // I want the alert to display 05, rather than 5.

How can I do this?

I could manually check the number and add a 0 to it as a string, but I was hoping there's a JS function that would do it?

Answer

There's no built-in JavaScript function to do this, but you can write your own fairly easily:

function pad(n) {
    return (n < 10) ? ("0" + n) : n;
}

Meanwhile there is a native JS function that does that. See String#padStart

console.log(String(5).padStart(2, '0'));