Add .00 (toFixed) only if number has less than two decimal places

Question

I need to add zeroes, so that each number has at least two decimals, but without rounding. So for example:

5      --> 5.00 5.1    --> 5.10 5.11   --> 5.11 (no change) 5.111  --> 5.111 (no change) 5.1111 -->  5.1111  (no change)  

My function is missing an IF to check for less than two decimal places:

function addZeroes( num ) {    var num = Number(num);    if ( //idk ) {       num = num.toFixed(2);    }    return num; } 

Thanks!

Posting an alternative answer, in addition to the two below. (Keep in mind that I'm no expert and this is just for text inputs, not for parsing complex values like colors that could have floating point issues, etc.)

function addZeroes( value ) {     //set everything to at least two decimals; removs 3+ zero decimasl, keep non-zero decimals     var new_value = value*1; //removes trailing zeros     new_value = new_value+''; //casts it to string      pos = new_value.indexOf('.');     if (pos==-1) new_value = new_value + '.00';     else {         var integer = new_value.substring(0,pos);         var decimals = new_value.substring(pos+1);         while(decimals.length<2) decimals=decimals+'0';         new_value = integer+'.'+decimals;     }     return new_value; } 

[This is not a duplicate question. The question you linked assumes "knowing that they have at least 1 decimal." Decimal points cannot be assumed in text inputs, and this was making errors.]

Answer 1

Here you go:

function addZeroes(num) { // Convert input string to a number and store as a variable.     var value = Number(num);       // Split the input string into two arrays containing integers/decimals     var res = num.split(".");      // If there is no decimal point or only one decimal place found.     if(res.length == 1 || res[1].length < 3) {  // Set the number to two decimal places         value = value.toFixed(2);     } // Return updated or original number. return value; }  // If you require the number as a string simply cast back as so var num = String(value); 

See updated fiddle for demonstration.

edit: Since I first answered this, javascript and I have progressed, here is an updated solution using es6, but following the same idea:

function addZeroes(num) {   const dec = num.split('.')[1]   const len = dec && dec.length > 2 ? dec.length : 2   return Number(num).toFixed(len) } 

Updated fiddle

Answer 2

Maybe use .toLocaleString():

var num = 5.1;     var numWithZeroes = num.toLocaleString("en",{useGrouping: false,minimumFractionDigits: 2}); console.log(numWithZeroes); 

As a function/demo:

function addZeroes(num) {     return num.toLocaleString("en", {useGrouping: false, minimumFractionDigits: 2})  }    console.log('before   after       correct');  console.log('5      ->', addZeroes(5) , '  --> 5.00');  console.log('5.1    ->', addZeroes(5.1) , '  --> 5.10');  console.log('5.11   ->', addZeroes(5.11) , '  --> 5.11 (no change)');  console.log('5.111  ->', addZeroes(5.111) , ' --> 5.111 (no change)');  console.log('5.1111 ->', addZeroes(5.1111) , '--> 5.1111 (no change)');  console.log('-5     ->', addZeroes(-5) , ' --> -5.00');

And if you must use .toFixed(), here's a one-liner:

var num = 5.1;     var numWithZeroes = num.toFixed(Math.max(((num+'').split(".")[1]||"").length, 2)); console.log(numWithZeroes); 

Or, again, as a function/demo:

function addZeroes(num) {     return num.toFixed(Math.max(((num+'').split(".")[1]||"").length, 2));  }    console.log('before   after       correct');  console.log('5      ->', addZeroes(5) , '  --> 5.00');  console.log('5.1    ->', addZeroes(5.1) , '  --> 5.10');  console.log('5.11   ->', addZeroes(5.11) , '  --> 5.11 (no change)');  console.log('5.111  ->', addZeroes(5.111) , ' --> 5.111 (no change)');  console.log('5.1111 ->', addZeroes(5.1111) , '--> 5.1111 (no change)');  console.log('-5     ->', addZeroes(-5) , ' --> -5.00');