JSFiddle - React, Tailwind, and code Playground

by jfriend00

JavaScript

var fillZeroes = "00000000000000000000";  // max number of zero fill ever asked for in global

function zeroFill(number, width) {
    // make sure it's a string
    var input = number + "";  
    var prefix = "";
    if (input.charAt(0) === '-') {
        prefix = "-";
        input = input.slice(1);
        --width;
    }
    var fillAmt = Math.max(width - input.length, 0);
    return prefix + fillZeroes.slice(0, fillAmt) + input;
}

var testValues = [0, 1, 88, 9999999, -1, -88, -999999];
var result;
for (var i = 0; i < testValues.length; i++) {
    result = zeroFill(testValues[i], 5);
    $(document.body).append(result + "<br>");
}