How to round a number down to 8 decimal places if its over 8 decimal places in Javascript

Question

I'm trying to check if a number inputed has over 8 decimal places and if it does then I want to round it back down to 8 decimal places. However, when I input the number 1.234001, it automatically rounds it to 8 decimal places. (1.234001 / 0.00000001) % 1 = 0 so I'm not sure why its rounding it. Here's my code

var SAT = 0.00000001;
if(!isNaN(input.value) && ((input.value / SAT) % 1 != 0)) {
                input.value = parseFloat(input.value).toFixed(8);
                console.log(6);
            }

Answer 1

Try it in this way:

function nrOfDecimals(number) {
    var match = (''+number).match(/(?:\.(\d+))?(?:[eE]([+-]?\d+))?$/);
    if (!match) { return 0; }

    var decimals =  Math.max(0,
       (match[1] ? match[1].length : 0)
       // Correct the notation.
       - (match[2] ? +match[2] : 0));

     if(decimals > 8){
        //if decimal are more then 8
        number = parseFloat(number).toFixed(8);
     }
     //else no adjustment is needed
     return number;
}