十进制比较，不舍入javascript

Question

I have 2 textboxex for decimal values and I need to compare them in JavaScript. The scenario is

var first = $('#txtFirst').val();
var second= $('#txtSecond').val();

In textboxex I'm entering following values

• first => 99999999999998.999999997

• second => 99999999999998.999999991

I tried the below code

     if (parseFloat(parseFloat(first).toFixed(10)) <= parseFloat(parseFloat(second).toFixed(10))) 

This returns true because it rounds it so both the values becomes 99999999999999. How to fix it?

Answer 1

Just compare without converting into integer

var first = $('#txtFirst').val();
var second= $('#txtSecond').val();

if ( first == second )
{
  // they are equal
}

if you want to compare upto 10 decimals then

var first10Decimals  = first.split(".").pop().substring(0,10);
var second10Decimals  = second.split(".").pop().substring(0,10);
if ( first10Decimals  == second10Decimals )
{
   //they are equal
}

Answer 2

Vanilla JavaScript can't handle such big numbers. You should use something like big.js that is designed to work with arbitrary large numbers :

• GitHub : https://github.com/MikeMcl/big.js/

• Documentation : https://mikemcl.github.io/big.js/