How to pass callback to init function in a class-CodePudding

As I mentioned in the title, I would like to pass some function as a callback to init function in some class

I will put here some basic structure:

class Person {

  constructor() {
    this.nums = [1, 2, 3];
    this.init();
  }

  init() {
    this.nums.forEach(num => {
      console.log(num);
    });
  }

}

Let's say I would like to add this function as a callback to the init function

test(){
  console.log('test')
}

How can i do this

CodePudding user response：

class Person {
  constructor(cb) {
    this.nums = [1, 2, 3];
    this.cb = cb;
    this.init()
  }
  init() {
    this.nums.forEach(num => {
      console.log(num)
    })
    this.cb()
  }
}

const test = () => {
  console.log('test')
}

const myPerson = new Person(test)

CodePudding user response：

Declare callback as a parameter in your init method, & call the callback at the end of your init method.

While calling your init method, pass test as an argument.

CodePudding user response：

In case the OP wants to have the callback invoked as if it was a method of the Person instance and in addition also wants to handle the passing of arguments to such a callback then init is not anymore just an initializer.

It turns into a single generic method of any Person instance which does invoke any passed function within such an instance' context while passing the rest of its arguments to the callback.

Such a method then might be renamed from init to execute ...

function pushNumberValues(...values) {
  this.nums.push(...(values.flat()));
}
function logInstanceNumbers() {
  this.nums.forEach(num =>
    console.log(num)
  );
}

class Person {
  constructor() {  
    this.nums = [0, 1, 2];
  }
  execute(callback, ...args) {
    return callback.apply(this, args);
  }
}
const person = new Person;

person.execute(pushNumberValues, 3, 4, 5, 6);
person.execute(pushNumberValues, [7 , 8 , 9]);

person.execute(logInstanceNumbers);

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