Dynamically access methods of class TypeScript

Question

I'm trying to access the methods of a class dynamically, using the value of a previously set variable in TypeScript.

class Foo {
    bar(){ }
}

var methodName = "bar";
var fooBar = new Foo();

fooBar.methodName(); // I would like this to resolve to fooBar.bar();

Answer 1

我们只需要离开强类型（和检查）世界，只使用 JavaScript 风格（这仍然很有用，例如在这些情况下）

fooBar[methodName]();

Answer 2

I believe an interface<\/a> will sort you out here...

interface FooInterface {
  bar: () => void
  // ...other methods
}

class Foo implements FooInterface {
  bar() {
    console.log('bar')
  }
  // .. other methods omitted
}

const foo = new Foo()

// good 
foo['bar']

// Element implicitly has an 'any' type because expression of type '"barry"' can't be used to index type 'Foo'.
//  Property 'barry' does not exist on type 'Foo'.
foo['barry']

let method: keyof FooInterface

// good
method = 'bar'
foo[method]()

// Type '"barry"' is not assignable to type 'keyof FooInterface'.
method = 'barry'
foo[method]()