Adding extra zeros in front of a number using jQuery?

Question

I have file that are uploaded which are formatted like so

MR 1

MR 2

MR 100

MR 200

MR 300

Answer 1

Assuming you have those values stored in some strings, try this:

function pad (str, max) {
  str = str.toString();
  return str.length < max ? pad("0" + str, max) : str;
}

pad("3", 3);    // => "003"
pad("123", 3);  // => "123"
pad("1234", 3); // => "1234"

var test = "MR 2";
var parts = test.split(" ");
parts[1] = pad(parts[1], 3);
parts.join(" "); // => "MR 002"

Answer 2

Try following, which will convert convert single and double digit numbers to 3 digit numbers by prefixing zeros.

var base_number = 2;
var zero_prefixed_string = ("000" + base_number).slice(-3);

Answer 3

In simple terms we can written as follows,

for(var i=1;i<=31;i++)
    i=(i<10) ? '0'+i : i;

//Because most of the time we need this for day, month or amount matters.

Answer 4

Note: see Update 2 if you are using latest ECMAScript...

---

Here a solution I liked for its simplicity from an answer to a similar question:

var n = 123

String('00000' + n).slice(-5); // returns 00123
('00000' + n).slice(-5);       // returns 00123

---

UPDATE

As @RWC suggested you can wrap this of course nicely in a generic function like this:

function leftPad(value, length) { 
    return ('0'.repeat(length) + value).slice(-length); 
}

leftPad(123, 5); // returns 00123

And for those who don't like the slice:

function leftPad(value, length) {
    value = String(value);
    length = length - value.length;
    return ('0'.repeat(length) + value)
}

But if performance matters I recommend reading through the linked answer before choosing one of the solutions suggested.

UPDATE 2

In ES6 the String class now comes with a inbuilt padStart method which adds leading characters to a string. Check MDN here for reference on String.prototype.padStart(). And there is also a padEnd method for ending characters.

So with ES6 it became as simple as:

var n = 123;
n.padStart(5, '0'); // returns 00123

Answer 5

I have a potential solution which I guess is relevent, I posted about it here:

https://www.facebook.com/antimatterstudios/posts/10150752380719364

basically, you want a minimum length of 2 or 3, you can adjust how many 0's you put in this piece of code

var d = new Date();
var h = ("0"+d.getHours()).slice(-2);
var m = ("0"+d.getMinutes()).slice(-2);
var s = ("0"+d.getSeconds()).slice(-2);

I knew I would always get a single integer as a minimum (cause hour 1, hour 2) etc, but if you can't be sure of getting anything but an empty string, you can just do "000"+d.getHours() to make sure you get the minimum.

then you want 3 numbers? just use -3 instead of -2 in my code, I'm just writing this because I wanted to construct a 24 hour clock in a super easy fashion.

Answer 6

function addLeadingZeros (n, length)
{
    var str = (n > 0 ? n : -n) + "";
    var zeros = "";
    for (var i = length - str.length; i > 0; i--)
        zeros += "0";
    zeros += str;
    return n >= 0 ? zeros : "-" + zeros;
}

//addLeadingZeros (1, 3) =   "001"
//addLeadingZeros (12, 3) =  "012"
//addLeadingZeros (123, 3) = "123"