Advanced Patterns

Preview — 3 of 10 questions

What will be the output of the following code?

javascript

function foo() {
  console.log(this);
}

foo();

Awindow (in browsers) or global (in Node.js)

Bundefined

Cnull

DReferenceError

Which of the following is not true about JavaScript closures?

javascript

function outer() {
  let count = 0;
  return function inner() {
    count++;
    return count;
  };
}

AA closure allows a function to remember variables from its outer scope.

BClosures help in creating private variables.

CA closure is created when a function is defined inside another function.

DClosures cannot access variables declared with let or const.

What will be logged by the following code?

javascript

let a = {};
let b = a;

console.log(a == b, a === b);

Atrue, true

Btrue, false

Cfalse, true

Dfalse, false

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