Arista Frontend Engineer - Round1

221

I was asked following questionin the interview.

what will be output of following code?

function test1() {
  console.log(this);
}
test1();

"use strict";
function test2() {
  console.log(this);
}
test2();

Answer :
window
this

call introduce with person's object.

function introduce(city, country) {
  console.log(`${this.name} is ${this.age} years old from ${city}, ${country}`);
}

const person = { name: "ABC", age: 20 };

Answer :

introduce.call(person, "Bangalore", "India");

const boundIntro = introduce.bind(person, "Bangalore", "India");
boundIntro();

call function from the object of function.

function Person(name) {
  this.name = name;
}

const sayHello = function() {
  console.log(`Hello, I am ${this.name}`);
};

const p1 = new Person("Arjun");
p1.sayHello();  // calling sayHello from object

Answer : I was not able to answer the question.

Person.prototype.sayHello = function() {
  console.log(`Hello, I am ${this.name}`);
};

implement custom reduce function

Answer : I was able to implement with little bit of help.

Array.prototype.customReduce = function(cb, init) {
  let acc = init === undefined ? this[0] : init;
  let i = init === undefined ? 1 : 0;
  for (; i < this.length; i++) {
    acc = cb(acc, this[i], i, this);
  }
  return acc;
};

[1, 2, 3, 4].customReduce((a, b) => a + b, 0);

Final Verdict : not selected.

Comments (1)