javascript - 算术运算符作为变量 javascript

Question

var x = 10;
var y = 5;
var action = '+';
var z = x action y; //15

是否可以将算术运算符指定为变量？

Answer 1

您可以只检查您想要支持的操作:

var x = 10;
var y = 5;
var action = '+';
var z = null;
if (action == '+') {
    z = x + y;
} else if (action == '-') {
    z = x - y;
} else if (action == '*') {
    z = x * y;
} else if (action == '/') {
    z = x / y;
} else {
    alert('Unsupported action');
}

还有eval函数允许你执行一些动态 javascript 语句，但它的使用经常被人皱眉:

var x = 10;
var y = 5;
var action = '+';
var z = window.eval(x + action + y);