decimal插件计算

import {
Decimal
} from 'decimal.js'; //引入
export const cal = {
jia(num1, num2) {
return new Decimal(num1).add(new Decimal(num2))
},
jian(num1, num2) {
return new Decimal(num1).sub(new Decimal(num2))
},
cheng(num1, num2) {
return new Decimal(num1).mul(new Decimal(num2))
},
chu(num1, num2) {
return new Decimal(num1).div(new Decimal(num2))
},
}

/* 解决js计算精度问题 */
export function cheng(arg1, arg2) {
var m = 0,
s1 = arg1.toString(),
s2 = arg2.toString();
try {
m += s1.split(".")[1].length
} catch (e) {}
try {
m += s2.split(".")[1].length
} catch (e) {}
return Number(s1.replace(".", "")) * Number(s2.replace(".", "")) / Math.pow(10, m);
}
export function jia(arg1, arg2) {
var r1, r2, m;
try {
r1 = arg1.toString().split(".")[1].length
} catch (e) {
r1 = 0
}
try {
r2 = arg2.toString().split(".")[1].length
} catch (e) {
r2 = 0
}
m = Math.pow(10, Math.max(r1, r2));
return (arg1 * m + arg2 * m) / m;

}

export function chu(arg1, arg2) {
var t1 = 0,
t2 = 0,
r1, r2;
try {
t1 = arg1.toString().split(".")[1].length
} catch (e) {}
try {
t2 = arg2.toString().split(".")[1].length
} catch (e) {}
r1 = Number(arg1.toString().replace(".", ""))
r2 = Number(arg2.toString().replace(".", ""))
return (r1 / r2) * Math.pow(10, t2 - t1);

}

export function jian(arg1, arg2) {
var r1, r2, m, n;
try {
r1 = arg1.toString().split(".")[1].length
} catch (e) {
r1 = 0
}
try {
r2 = arg2.toString().split(".")[1].length
} catch (e) {
r2 = 0
}
m = Math.pow(10, Math.max(r1, r2));
//lastmodifybydeeka
//动态控制精度长度
// n = (r1 >= r2) ? r1 : r2;
return ((arg1 * m - arg2 * m) / m);
}

// 实例
this.contractPriceExcludingValueAddedTax = cal.chu(this.subtotal, (cal.jia(1, 0)))

这样计算就不会出现精度失真为问题，但是为了保障代价的可靠性还是需要再用户输入框中限制用户输入为整数或者最多两位小数的限制。