Display Big decimal Number in Java script

Question

I am new in javascript,so please forgive if it is worthless question. However,I have big decimal number which I need to show without any exponential notation.

For e.g. var a = 0.00000000005545545468864654 should be shown as 0.00000000005545545468864654 instead of 5.545545468864654e-11

Can anyone help me regarding it.

I have tried the below approach

var a = 0.00000000005545545468864654
Number.parseFloat(a).toFixed(30)

where 30 is the count of decimal places.But this approach is not working and giving result "0.000000000055455454688646537182" which is not "0.00000000005545545468864654"

score 1 · Answer 1 · answered Jun 13 '18 at 07:03

1

Why 30 decimal places when you have only 26.

var a = 0.00000000005545545468864654
console.log(Number.parseFloat(a).toFixed(26));

answered Jun 13 '18 at 07:03

Matus Dubrava

13,637
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38
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Thanks for your help,But this is not working when we have value like this 1.00000000005545545468864654 – Ankur Sharma Jun 13 '18 at 07:11
can you please suggest regarding 1.00000000005545545468864654 – Ankur Sharma Jun 13 '18 at 09:42

score 0 · Answer 2 · answered Jun 13 '18 at 07:04

0

You can use a function if you want:

function toFixed(x) {
  if (Math.abs(x) < 1.0) {
    var e = parseInt(x.toString().split('e-')[1]);
    if (e) {
        x *= Math.pow(10,e-1);
        x = '0.' + (new Array(e)).join('0') + x.toString().substring(2);
    }
  } else {
    var e = parseInt(x.toString().split('+')[1]);
    if (e > 20) {
        e -= 20;
        x /= Math.pow(10,e);
        x += (new Array(e+1)).join('0');
    }
  }
  return x;
}

const num = 0.00000000005545545468864654;

console.log(toFixed(num))

answered Jun 13 '18 at 07:04

wobsoriano

12,348
24
92
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Sorxrob: This is not working :( – Ankur Sharma Jun 13 '18 at 07:18
What do you mean it's not working? – wobsoriano Jun 13 '18 at 07:19
you can check the result the number you are passing is not exactly what you are getting – Ankur Sharma Jun 13 '18 at 08:43

score 0 · Answer 3 · answered Jun 13 '18 at 07:48

Precision is an intrinsic issue of binary representation of decimal numbers. There are techniques and precision setters which will work well only up to a certain precision. Then limits are hit. It is not an issue it's possible to solve but workarounds include:

converting every digit to int and keeping them separate, print with a toString, define custom operations
multiplying chunks of decimal digits before performing operations and then dividing back, which may or may not work and may or may not scale. This includes converting numbers to ints by multiplying by a power of 10.

And of course libraries have been made to address this concern. Check BigNumbers based on decimaljs

Display Big decimal Number in Java script

3 Answers3