运算精度问题https://blog.csdn.net/smile_ping/article/details/80284969

export default {

add(num1, num2) {

let r1;

let r2;

try { r1 = num1.toString().split('.')[1].length; } catch (e) { r1 = 0; }

try { r2 = num2.toString().split('.')[1].length; } catch (e) { r2 = 0; }

const m = 10 ** Math.max(r1, r2);

const n = (r1 >= r2) ? r1 : r2;

return ((num1 * m + num2 * m) / m).toFixed(n);

},

sub(num1, num2) {

let r1;

let r2;

try { r1 = num1.toString().split('.')[1].length; } catch (e) { r1 = 0; }

try { r2 = num2.toString().split('.')[1].length; } catch (e) { r2 = 0; }

const n = (r1 >= r2) ? r1 : r2;

const m = 10 ** Math.max(r1, r2);

return ((num1 * m - num2 * m) / m).toFixed(n);

},

mul(num1, num2) {

let m = 0;

try { m += num1.toString().split('.')[1].length; } catch (e) { m += 0; }

try { m += num2.toString().split('.')[1].length; } catch (e) { m += 0; }

return (Number(num1.toString().replace('.', '')) * Number(num2.toString().replace('.', ''))) / (10 ** m);

},

div(arg1, arg2) {

let t1;

let t2;

try { t1 = arg1.toString().split('.')[1].length; } catch (e) { t1 = 0; }

try { t2 = arg2.toString().split('.')[1].length; } catch (e) { t2 = 0; }

const r1 = Number(arg1.toString().replace('.', ''));

const r2 = Number(arg2.toString().replace('.', ''));

return (r1 / r2) * (10 ** (t2 - t1));

},

};