Dcmal

Dcmal.js

class Dcmal {
    constructor(prec) {
        this.prec = prec;
    }
    _noExponents(num) {
        var data = String(num).split(/[eE]/);
        if (data.length == 1) return data[0];

        var z = '',
            sign = this < 0 ? '-' : '',
            str = data[0].replace('.', ''),
            mag = Number(data[1]) + 1;

        if (mag < 0) {
            z = sign + '0.';
            while (mag++) z += '0';
            return z + str.replace(/^\-/, '');
        }
        mag -= str.length;
        while (mag--) z += '0';
        return str + z;
    }
    round(num) {

        let minus = parseInt(num) < 0 ? '-' : ''
        num = Math.abs(num)



        let str = this._noExponents(num)

        str = str.replace(",", ".").split(".")

        let prec = this.prec

        if (str[1] !== undefined) {
            prec = str[1].length < this.prec ? str[1].length : this.prec
        } else {
            prec = 0
        }

        let last = parseInt(str[1])



        if (num < 1 && num > 0) {
            return minus + "0." + str[1].replace(last, "") + parseFloat("0." + last).toFixed(prec).replace(",", ".").split(".")[1]
        } else {
            return minus + num.toFixed(prec)
        }

    }
}