function doStuff(s) { if (s.indexOf('.') == -1) s += '.'; while (s.length <= s.indexOf('.') + 2) s += '0'; return s; } console.log(doStuff("3")); console.log(doStuff("3.0")); console.log(doStuff("3.1")); console.log(doStuff("3.00")); console.log(doStuff("3.10")); console.log(doStuff("3.01")); console.log(doStuff("3.22")); console.log(doStuff("3.224")); console.log(doStuff("3.000"));