this in javascript: methods and scope

Question

I'm having a doubt about the this reference to object and global scope. I know that a method inside an object is refering to the object who contains that function. And that a normal function will refer to the window object. But for some reason it changes depending on how i write it. At least in this code:

this.name = 'global scope'

function log() {
  console.log(this.name);
}

const obj1 = {
  name: 'obj1 scope',
  objlog1: function() {
    console.log(this.name);
  },
  objlog2() {
    console.log(this.name);
  },
  objlog3: log,
  objlog4: function() {
    log()
  },
  objlog5: log()
}

obj1.objlog1(); //obj1 scope
obj1.objlog2(); //obj1 scope
obj1.objlog3(); // obj1 scope
obj1.objlog4(); // global scope
obj1.objlog5 // it executes before i call it for some reason? global scope.

obj1,2,3, is all ok because it marks the obj1 scope. But the obj4 marks the global scope (and it's just a function that calls another function, should be as obj3, right?) and the objlog5 is even executed before I call it (I think it has to be something related to the ()). Sorry if this sounds very 'newbie' question, but I'm having trouble understanding the this.

"name" in global is going to be window.name which is going to lead to fun debugging problems. — epascarello, Aug 24 '21 at 19:18
`objlog5: log()` <-- because you call the function and assign what it returns to the property. — epascarello, Aug 24 '21 at 19:22
https://stackoverflow.com/questions/4616202/self-references-in-object-literals-initializers — epascarello, Aug 24 '21 at 19:23
learn `this` in two minutes. https://www.youtube.com/watch?v=kb0Af7dzCTs — Abbas, Aug 24 '21 at 19:27

this in javascript: methods and scope

0 Answers0