I need to round a value with 2 decimal places that I receive from a web service. To do this i use this methods toFixed and parseFloat because I need the final value in a float. However when I have this value "5.5000000" he shows me the value with only one decimal place "5.5"...

I did in that way:

var num = 5.5000000;
var n = num.toFixed(2);
var numFinal = parseFloat(n);

I need to round a value with 2 decimal places that I receive from a web service. To do this i use this methods toFixed and parseFloat because I need the final value in a float. However when I have this value "5.5000000" he shows me the value with only one decimal place "5.5"...

I did in that way:

var num = 5.5000000;
var n = num.toFixed(2);
var numFinal = parseFloat(n);

• javascript

• If you have a number and want a string you don't need parseFloat() because that function does the exact opposite (convert from string to number). – Álvaro González Commented Jun 17, 2016 at 11:40
• but the method toFixed returns a string and i want a float – sampaioPT Commented Jun 17, 2016 at 13:55
• "5.5000000" is just how the float happens to be displayed when you print it. There's no direct translation between the internal base 2 representation of a floating point number and decimals in a given base 10 representation. – Álvaro González Commented Jun 17, 2016 at 14:53
• 1 @sampaioPT, Refer stackoverflow./a/2283670/1746830 – Rayon Commented Jun 18, 2016 at 4:48
• 1 Thanks for reply @ÁlvaroGonzález! Now i understand! (I owe you one beer ;) ) – sampaioPT Commented Jun 20, 2016 at 15:53

3 Answers 3

You have to call toFixed after parseFloat:

parseFloat(yourString).toFixed(2)

Short Answer: There is no way in JS to have Number datatype value with trailing zeros after a decimal.

Long Answer: Its the property of toFixed or toPrecision function of JavaScript, to return the String. The reason for this is that the Number datatype cannot have value like a = 2.00, it will always remove the trailing zeros after the decimal, This is the inbuilt property of Number Datatype. So to achieve the above in JS we have 2 options

1. Either use data as a string or
2. Agree to have truncated value with case '0' at the end ex 2.50 -> 2.5. Number Cannot have trailing zeros after decimal

You can do something like this

   /**
       * Convert the value to the Number with the precision.
       * @param   {Number} value         value to be converted
       * @param   {Number} [precision=0] number of decimal places
       * @returns {Number} converted number.
       */
      function toNumber (value, precision) {
        precision = precision || 0;
        if (precision === 0) {
          return value * 1;
        } else {
          return Number((value * 1).toFixed(precision));
        }
      }