Output Basics — Series 2

Preview — 3 of 10 questions

What is the output?

javascript

console.log(NaN === NaN);
console.log(NaN == NaN);
console.log([NaN].includes(NaN));

Atrue, true, true

Btrue, false, true

Cfalse, false, true

Dfalse, false, false

What is the output?

javascript

const arr = [1, 2, 3];

console.log(typeof arr);
console.log(Array.isArray(arr));
console.log(arr instanceof Array);

A"array", true, true

B"object", false, true

C"object", true, false

D"object", true, true

What is the output?

javascript

const key = 'color';
const value = 'blue';

const obj = {
  [key]: value,
  size: 10,
};

console.log(obj.color);
console.log(obj[key]);
console.log(Object.keys(obj));

Aundefined, "blue", ["key", "size"]

B"blue", "blue", ["color", "size"]

C"blue", "blue", ["key", "size"]

Dundefined, undefined, ["color", "size"]

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