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

var str = "43215"; 
console.log("Before : \n string :"+str+"\n Length :"+str.length);
var max = 9;
while(str.length < max ){
                                str = "0" + str;

                        }
console.log("After : \n string :"+str+"\n Length :"+str.length);

It worked for me ! To increase the zeroes, update the 'max' variable

Working Fiddle URL : Adding extra zeros in front of a number using jQuery?: