如何使用变量引用类

Question

If I have this object:

var myclass = {

  foo: {
    bar: function(var) {}
  },
  some: {
    bar: function(var) {}
  }
}

and I want to call the bar function depending on a variable that defines the parent level of the object like this:

var part = "some";
myclass.part.bar(var);

How can I do?

Answer 1

You can do it using array access notation:

myclass[part].bar(var);

JavaScript objects are like associative arrays, and you can use a property name to either set or get the property's value, you can even create new properties with this syntax.

For example:

var obj = { a : 1 };
console.log(obj["a"]); // 1
obj["b"] = 2; // this creates a property called b and assigns 2 as the value
console.log(obj["b"]); // 2

Answer 2

You can keep a reference to a function as a variable, which is a little cleaner than a string.

var func = myclass.foo.bar;//or myclass.some.bar
...
func.call(myclass, var);

Or keep a reference to the part:

var part = myclass.foo;//or myclass.some
part.bar.call(myclass, var);