let obj = {
one: function(){
this.two();
},
two: function(){
console.log("two");
}
}
let oneFunc = obj.one;
obj.one(); // two
oneFunc(); // TypeError: this.two is not a function
I have been programming in JavaScript for quite some time. I thought I had a really solid grasp on the this keyword. However, I ran in to this today and it blew my mind. I can't figure out why this is happening. When I call oneFunc(), this refers to the global object. Why does this happen?
this refere to the object, and what you are doing here is creating a function equal to the methode of the object and so you lose the reference to the object.
You can use bind
let obj = {
one: function(){
this.two();
},
two: function(){
console.log("two");
}
}
let oneFunc = obj.one;
oneFunc = oneFunc.bind(obj);
obj.one(); // two
oneFunc(); // TypeError: this.two is not a function