JavaScript String padStart()

Pad a string with "0" until it reaches the length 4:

let text = "5";
let padded = text.padStart(4,"0");

Pad a string with "x" until it reaches the length 4:

let text = "5";
let padded = text.padStart(4,"x");

Description

The padStart() method pads a string from the start.

The padStart() method pads a string with another string (multiple times) until it reaches a given length.

The padStart() method is a string method.

To pad a number, convert the number to a string first.

See the example below.

let numb = 5;
let text = numb.toString();
let padded = text.padStart(4,"0");

string.padStart(length, string)

Parameter	Description
length	Required. The length of the resulting string.
string	Optional. The string to pad with. Default is space.

Type	Description
A string	A String of the specified length, with the padding applied from the start.

padStart() is an ECMAScript 2017 feature.

ES2017 is supported in all modern browsers since September 2017:


Chrome 58	Edge 15	Firefox 52	Safari 11	Opera 45
Apr 2017	Apr 2017	Mar 2017	Sep 2017	May 2017

padStart() is not supported in Internet Explorer.