按名称调用函数

2022-01-24 00:00:00 javascript coffeescript

有时我们需要通过函数名来调用函数.我可以用纯 JavaScript 来完成，如下所示:

Sometimes we need to call a function by its name. I can do it in plain JavaScript as below:

global=this
function add(a,b){return a+b}
global['add'](1,2)

按预期工作，add() 被调用.

Which works as expected and add() gets called.

等效的 CoffeeScript 代码可以写成如下.

Equivalent CoffeeScript code might can be written as below.

global=@
add=(a,b)->a+b
global['add'](1,2)

编译成 JavaScript 为:

which compiles to JavaScript as:

(function() {
  var add, global;
  global = this;
  add = function(a, b) {
    return a + b;
  };
  global['add'](1, 2);
}).call(this);

...它不起作用.

Microsoft JScript runtime error: Object doesn't support this property or method

这个问题有简单的解决方法吗?

Is there an easy solution to this problem?

注意:

  1. 我没有在浏览器中运行代码，因此没有窗口对象.但是在普通的 JS 中，我总是可以通过分配 global=this 来捕获全局范围，然后从中获取函数指针.

  1. I am not running the code in a browser therefore there is no window object. But in plain JS I can always capture the global scope by assigning global=this and then get the function pointer from it.

我发现 CoffeeScript 中的一个解决方案是将所有函数声明为像 global.add=[function definition] 这样的全局对象的成员.但是我通常必须将该函数称为 global.add().而且它比必要的样板更多.

One solution in CoffeeScript I found is by declaring all functions as member of a global object like global.add=[function definition]. But then I have to normally call the function as global.add(). And it's more boiler plate than necessary.

有简单的技巧吗?还是有更简单的解决方案?

Is there a simple hack? Or any simpler solution?

推荐答案

你的 add 是一个局部变量.使用

Your add is a local variable. Use

@add=(a,b)->a+b

将其附加到 global 对象.由于 global 是脚本的全局范围，您仍然可以调用 add 而无需在其前面加上 global..

to attach it to the global object. Since global is the global scope of your script you can still call add without prefixing it with global..

相关文章