The "this" keyword

Question 1

The ‘this’ keyword evaluates to the value of the … of the current execution context

Answer 1

The ‘this’ keyword evaluates to the value of the ThisBinding of the current execution context

Question 2

The … site determines the …Binding

Answer 2

The callsite determines the ThisBinding

Question 3

This is the … that owns the method in a method invocation

Answer 3

This is the object that owns the method in a method invocation

Question 4

When invoking a method on an object, this becomes …

Answer 4

When invoking a method on an object, this becomes the object itself

Question 5

In non-strict mode, a function’s internal ThisBinding defaults to …

Answer 5

In non-strict mode, a function’s internal ThisBinding defaults to the global object (the window object in a browser)

Question 6

In regards to the ThisBinding, there is an important distinction between … invocation & … invocation

Answer 6

In regards to the ThisBinding, there is an important distinction between function invocation & method invocation

Question 7

In regards to prototypal inheritance, the ThisBinding is still the context of the …, even when the prototype chain is queried

Answer 7

In regards to prototypal inheritance, the ThisBinding is still the context of the invocation, even when the prototype chain is queried

Question 8

What is this automatically set to in a constructor function?

Answer 8

This is set to the newly created object

Question 9

If we run a function in the global execution context, and console.log the this value inside the function, what will we see when we call the function?

Answer 9

We will see ‘window’ in a browser in non-strict mode.

We will see undefined in strict-mode.

Question 10

In ES6 classes, methods called on a class use the … as the ThisBinding

Answer 10

In ES6 classes, methods called on a class use the object itself as the ThisBinding

Question 11

Do arrow functions have their own ThisBinding?

Answer 11

No, arrow functions defer to the ThisBinding of their surrounding lexical context

Question 12

What is the difference between call & apply?

Answer 12

Both call and apply take an object as their first argument, which sets the this value of a function. However, call takes a list of comma separated arguments as optional inputs, while apply takes an array of arguments as the second optional argument.

Question 13

Name 3 methods that can explicitly change the this value of a function.

Answer 13

.call()
.apply()
.bind()

Question 14

Every single JavaScript program is executed within an …

Answer 14

Execution Context

Question 15

Every execution context has a …

Answer 15

ThisBinding

Question 16

Is ‘this’ a reference to the function’s lexical scope?

Answer 16

No.