Javascript toFixed function

Question

The expected result of:

(1.175).toFixed(2) = 1.18 and
(5.175).toFixed(2) = 5.18

But in JS showing:

Answer 1

It's because the numbers are stored as IEEE754.

I would recommend you to use the Math class (round, floor or ceil methods, depending on your needing).

I've just created a class MathHelper that can easily solve your problem:

var MathHelper = (function () {
    this.round = function (number, numberOfDecimals) {
        var aux = Math.pow(10, numberOfDecimals);
        return Math.round(number * aux) / aux;
    };
    this.floor = function (number, numberOfDecimals) {
        var aux = Math.pow(10, numberOfDecimals);
        return Math.floor(number * aux) / aux;
    };
    this.ceil = function (number, numberOfDecimals) {
        var aux = Math.pow(10, numberOfDecimals);
        return Math.ceil(number * aux) / aux;
    };

    return {
        round: round,
        floor: floor,
        ceil: ceil
    }
})();

Usage:

MathHelper.round(5.175, 2)

Demo: http://jsfiddle.net/v2Dj7/