math-all/index.ts

Versatile JavaScript library for precise rounding of decimal places and significant digits.

const MathAll = {
  round: function (target: number, digit: number): number {
    const copiedTarget = target < 0 ? -1 * target : target;
    const isNegative = target < 0 ? true : false;

    if (digit >= copiedTarget.toString().length) {
      throw new Error("digit can't be over the target's digit");
    } else if (digit > 100 || digit < -100) {
      throw new Error("digits argument must be between -100 and 100 ");
    } else if (digit > -100 && digit < 0) {
      const result = Number(
        Math.round((copiedTarget + "e" + -1 * digit) as any) + "e-" + -1 * digit
      );
      return isNegative ? -1 * result : result;
    } else {
      const result = Number(
        Math.round(copiedTarget / 10 ** digit) * 10 ** digit
      );
      return isNegative ? -1 * result : result;
    }
  },
};
export { MathAll };