变量运算符可能吗？ [英] Are Variable Operators Possible?

问题描述

有没有办法做类似于以下任何一种情况：

Is there a way to do something similar to either of the following:

var1 = 10; var2 = 20;
var operator = "<";
console.log(var1 operator var2); // returns true

- 或 -

var1 = 10; var2 = 20;
var operator = "+";
total = var1 operator var2; // total === 30

推荐答案

不出来框。但是，很容易用包括JS在内的多种语言手工构建。

Not out of the box. However, it's easy to build by hand in many languages including JS.

var operators = {
    '+': function(a, b) { return a + b },
    '<': function(a, b) { return a < b },
     // ...
};

var op = '+';
alert(operators[op](10, 20));

您可以使用基于ascii的名称，例如加上，如果你不需要，避免通过字符串。然而，有一半类似于这个问题的问题被问到了，因为有人用字符串表示操作符和想要的函数。

You can use ascii-based names like plus, to avoid going through strings if you don't need to. However, half of the questions similar to this one were asked because someone had strings representing operators and wanted functions from them.

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