如何在变量中加号

问题描述

我想计算两个数字而且非常简单。

I want to calculate two numbers and its pretty simple.

但是有没有办法在变量中运算运算符然后进行计算？

But Is there any way to take operator in variable and then do the calculation?

var x = 5;
var y = 5;
var p = '+';
var z = x + p + y;

$(".button").click(function() {
  alert(z);
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div class="button">Click ME !</div>

推荐答案

尽可能避免 eval 。对于此示例，一个简单的 switch ... case 语句就足够了：

Avoid eval whenever possible. For this example, a simple switch...case statement will be sufficient:

var x = 5;
var y = 5;
var z;
var p = "+";
switch (p) {
    case "+":
        z = x + y;
        break;
    case "-":
        z = x - y;
        break;
}

---

您还可以使用功能图：

---

You can also use a map of functions:

var fnlist = {
    "+": function(a, b) { return a + b; },
    "-": function(a, b) { return a - b; }
}
var x = 5;
var y = 5;
var p = "+";
var z = fnlist[p](x, y);

这篇关于如何在变量中加号的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！