In C# whenever I wanted to print two digit numbers I've used

int digit=1;
Console.Write(digit.ToString("00"));

How can I do the same action in Javascript ?
Thanks

In C# whenever I wanted to print two digit numbers I've used

int digit=1;
Console.Write(digit.ToString("00"));

How can I do the same action in Javascript ?
Thanks

• javascript
• string
• formatting

• possible duplicate of Javascript printf/string.format – Jerod Venema Commented Jun 2, 2011 at 21:43

4 Answers 4

c# digit.toString("00") appends one zero to the left of digit (left padding). In javascript I use this functon for that:

function zeroPad(nr,base){
  var  len = (String(base).length - String(nr).length)+1;
  return len > 0? new Array(len).join('0')+nr : nr;
}
zeroPad(1,10);   //=> 01
zeroPad(1,100);  //=> 001
zeroPad(1,1000); //=> 0001

You can also rewrite it as an extention to Number:

Number.prototype.zeroPad = Number.prototype.zeroPad || 
     function(base){
       var nr = this, len = (String(base).length - String(nr).length)+1;
       return len > 0? new Array(len).join('0')+nr : nr;
    };
 //usage:
(1).zeroPad(10);   //=> 01
(1).zeroPad(100);  //=> 001
(1).zeroPad(1000); //=> 0001

[edit oct. 2021]

A static es20xx Number method, also suitable for negative numbers.

Number.padLeft = (nr, len = 2, padChr = `0`) => 
  `${nr < 0 ? `-` : ``}${`${Math.abs(nr)}`.padStart(len, padChr)}`;
console.log(Number.padLeft(3));
console.log(Number.padLeft(284, 5));
console.log(Number.padLeft(-32, 12));
console.log(Number.padLeft(-0)); // Note: -0 is not < 0

I usually just do something like ("00000000"+nr).slice(-base) where nr is the number and base is the number of digits you want to end up with.

One way would be to download sprintf for javascript and writing something like this:

int i = 1;
string s = sprintf("%02d", i);
document.write(s); // Prints "01"

var num =10
document.write(num);

But if your question is to use two digit numbers twice then you can use this

var num1 = 10;
var num2 = 20;
var resultStr = string.concat(num1,num2);
document.write(resultStr);
...
Result: 1020

if you want a space in between,

var resultStr = string.concat(num1,"",num2);

Hope this helps...