The JavaScript Interview Handbook: 100+ Interview Questions/

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Solution Review: `this` Keyword

Solution Review: `this` Keyword

In this lesson, we will discuss the solutions to the questions in the previous lesson.

We'll cover the following...

Question 1: Solution review #

In the previous lesson, you were given the following code:

Javascript (babel-node)
length = 10;
function func() {
	console.log(this.length);
}
var obj = {
  length: 5,
  thisFunc: function(func) {
    func.call(this);
    arguments[0]();
  }
};
obj.thisFunc(func, 3);

For the code above, you had to answer the following question:

Explanation #

The solution is given below.

As you can see, Option D is the correct answer. Let’s discuss the code to understand the answer.

Let’s start from line 14, where we are calling obj.thisFunc.

obj.thisFunc(func, 3);

We are passing it an argument, the function func, and an extra argument, the number 3.

We pass func to thisFunc at a global level, so the ...