how can i use this of obj in sayHi()
i want this in sayHi to refer to this in obj what changes should i add to sayHi so it prints harry potter instead of undefined
let obj = {
fullName: "Harry Potter",
person: {
sayHi: function(){
return "This person's name is " + this.fullName
}
}
}
is there another way than this obj.person.sayHi.call(obj) or obj.person.sayHi.apply(obj) to do it;
You can use apply()
var obj = {
fullName: "Harry Potter",
person: {
sayHi: function(){
return "This person's name is " + this.fullName
}
}
}
console.log(obj.person.sayHi.apply({fullName: 'John'}))
console.log(obj.person.sayHi.apply(obj))Inside sayHi() function the this refers the sayHi function but not the object obj. So in this scenario you can bind the reference this using .call()
var obj = {
fullName: "Harry Potter",
person: {
sayHi: function() {
return "This person's name is " + this.fullName
}
}
}
console.log(obj.person.sayHi.call(obj))
.bind(obj) instead.No, there isn't. obj contains a reference to the object in it's person property, the object however doesn't know were it is in, it could also be referenced at multiple places.
You could create a reference from person to obj:
obj.person.parent = obj;
Then you can access it as this.parent.
You don't need it, but I think it's more appropriate to use classes for this case.
class Person{
constructor(fullName){
this.fullName=fullName;
}
sayHi(){
return "This person's name is " + this.fullName
}
};
HP = new Person("Harry Potter");
HP.sayHi()
"This person's name is Harry Potter"
bindinstead ofcall. It's a similar concept though: developer.mozilla.org/de/docs/Web/JavaScript/Reference/…varinside function is private / local scopeobj.fullNameif you don't want to usecallorapply.thisin this case points toperson. Not sure if that's what you intend to do