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JavaScript Practice Questions - Part 2

Prashant Surya | Feb 28, 2020 | Views: 101

Description:

What will be the outputs of the following questions ?

Question 11:

(function(x) {
    return (function(y) {
        console.log(x);
    })(2)
})(1);

Question 12:


var hero = {
    _name: 'John Doe',
    getSecretIdentity: function (){
        return this._name;
    }
};
var stoleSecretIdentity = hero.getSecretIdentity;
console.log(stoleSecretIdentity());
console.log(hero.getSecretIdentity());

undefined

John Doe

Question 13:

var length = 10;
function fn() {
	console.log(this.length);
}
var obj = {
  length: 5,
  method: function(fn) {
    fn();
    arguments[0]();
  }
};
obj.method(fn, 1);

Question 14:

(function () {
    try {
        throw new Error();
    } catch (x) {
        var x = 1, y = 2;
        console.log(x);
    }
    console.log(x);
    console.log(y);
})();

undefined

Question 15:

var x = 21;
var girl = function () {
    console.log(x);
    var x = 20;
};
girl ();

undefined

Question 16:

for (let i = 0; i < 5; i++) {
  setTimeout(function() { console.log(i); }, i * 1000 );
}

0 1 2 3 4

Question 17:

console.log(1 < 2 < 3);
console.log(3 > 2 > 1);

true

Question 18:

var a = [1, 2, 3];
a[10] = 99;
console.log(a[6]);

undefined

Question 19:

typeof undefined == typeof NULL

true

Question 20:


console.log(typeof typeof 1);

string

Question 21:


var b = 1;
function outer(){
   	var b = 2
    function inner(){
        b++;
        var b = 3;
        console.log(b)
    }
    inner();
}
outer();

Comments:

Content Contributor★★★★★

Prashant Surya

Software developer at Uniserve Data Technologies Pvt. Ltd. | Noida, Uttar Pradesh, India

I am a software developer, freelancer and trainer working on technologies likes. MEAN stack, MERN Stack, ASP.NET full stack, WebRTC, socket.io ,PWA, SQL, JavaScript, jQuery, HTML, CSS, SEO, responsive UI/UX designing... having 7 years of experience in development in multiple domains like, eCommerce, RTA, capital markets, education, real estate...