JavaScript-this

Question 1

What is “this” in JavaScript

Answer 1

It’s an implicit parameter that references the object that is executing the current function

Question 2

What does it mean to say that “this” is an “implicit parameter”?

Answer 2

It is available in a function’s code block even though ti was never included in the function’s parameter list or declared with var.

Question 3

When is the value of this determined in a function; call time or definition time?

Answer 3

Call time

Question 4

What does this refer to in the following code snippet? 
var character = {
firstName: 'Mario",
greet: function ( ) {
var message = 'It\'s-a-me, ' + this.firstName + '!';
console.log(message):
)};

Answer 4

The value of the firstName property in the object, character.

Question 5

Given the above character object, what is the result of the following code snippet? Why? character.greet( );

Answer 5

“It’s-a-me, Mario!” because it’s within the object.

Question 6

Given the above character object, what is the result of the following code snippet? Why? 
var hello = character.greet;
hello ( );

Answer 6

“it’s-a-me, undefined!”

Question 7

How can you tell what the value of “this” will be for a particular function or method definition?

Answer 7

The object to the left of the dot

Question 8

How can you tell what the value of this is for a particular function or method call?

Answer 8

I don’t know.