Advanced Output Traps — Series 2

Preview — 3 of 10 questions

What is the output?

javascript

const arr = [1, , 3];
let forEachCount = 0;

arr.forEach((item) => {
  forEachCount++;
});

let forLoopCount = 0;
for (let i = 0; i < arr.length; i++) {
  forLoopCount++;
}

console.log(forEachCount);
console.log(forLoopCount);
console.log(arr[1]);

A3, 3, undefined

B2, 2, undefined

C2, 3, undefined

D3, 3, 3

What is the output?

javascript

const proto = {
  get value() {
    return 42;
  },
};

const obj = Object.create(proto);

function trySet() {
  'use strict';
  obj.value = 100;
}

try {
  trySet();
} catch (e) {
  console.log(e instanceof TypeError);
}

console.log(obj.value);

Afalse, 100

Btrue, 100

Cfalse, 42

Dtrue, 42

What is the output?

javascript

const items = ['a', 'b', 'c'];
const log = [];

for (const item of items) {
  setTimeout(() => log.push(item), 0);
}

setTimeout(() => console.log(log), 10);

A[]

B["a", "b", "c"]

C["c", "c", "c"]

D["c", "b", "a"]

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