Daily JavaScript Quiz - 2024-03-16

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Daily JavaScript Quiz - 2024-03-16

Predict the output of the following JavaScript code snippet - 2024-03-16

var x = 5;
function test() {
        console.log(this.x === x);
}
test();

true

false

ReferenceError: y is not defined

TypeError: Cannot read property ’toString’ of undefined

The answer is Option 1

In this JavaScript code, you’re declaring a variable x with a value of 5 and defining a function test(). Inside test(), you’re comparing this.x with the outer variable x. Let’s break it down:

var x = 5;

Declares a variable x and assigns it the value 5.

function test() {
    console.log(this.x === x);
}

Defines a function named test.
Inside the function, it logs the result of the comparison this.x === x.
this.x refers to the value of x in the context of the function invocation.
x refers to the outer variable declared in the global scope.

test();

Calls the test function.

In this case, since the function test is not invoked with any specific context, this inside the function refers to the global object (in browsers, it would be the window object). So, this.x refers to the global variable x which is 5. Therefore, the comparison this.x === x evaluates to true, and true will be logged to the console.

So, the output of this code will be:

true

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