Top 10 Javascript Interview Question And Answer

1. Top 10 Javascript Interview Ques Top 10 Javascript Interview Question And Answer tion And Answer It is best to get in now, when the technology is still in its infancy, if you intend to establish a career in JavaScript and want to learn the skills associated with it. You will gain in-depth knowledge through our JavaScript training and from our JavaScript interview questions And JavaScript quiz, which will help you get ready for your interviews. Q1.What are the scopes of a variable in JavaScript? Answar: The area of your programme where a variable is defined is its scope. Only two scopes are available for JavaScript variables. Global Variables- A global variable is visible throughout your JavaScript code since it has a global scope. Local variables- Local variables are only accessible within the function in which they are defined. The parameters of a function are always specific to that function. Q2. What is closure in JavaScript? Answer: An inner function with access to the variables in the outer function's scope chain is referred to as a closure. Three scoped variables are accessible to the closure: 1. Variables in their own scope

2. 2.Variables in the function’s scope 3. Global variables Q3. What are screen objects? Define its properties? Answer: This is an example of an advanced Javascript interview question. To read various kinds of information from a client screen, screen objects are employed. These are the properties: The screen's height is specified. Images from the client's screen are additionally offered. The screen's width is specified. The taskbar and screen items are included in the client screen's total height measurement. Q4. How does TypeOf Operator work? Answer: To determine the data type of its operand, use the typeof operator. A literal or a data structure, such as a variable, function, or object, can serve as the operand. Prior to its sole operand, which can be of any type, it is a unary operator. Its value is a string that specifies the operand's data type. Q5. How to create a cookie using JavaScript?

3. Answer: The simplest way to create a cookie is to provide the document a string value. a thing that resembles a cookie- Syntax : document.cookie = "key1 = value1; key2 = value2; expires = date"; Q6. Why do we use “use strict” at the beginning of the JS file? Answer:“use-strict” is a method to enforce strict parsing and error handling at runtime. There could be some code errors that could be ignored, but now they will be thrown explicitly. Q7. What is the difference between Attributes and Property? Answer: Attributes- provide more details on an element like id, type, value etc. Property- is the value assigned to the property like type=”text”, value=’Name’ etc. Q8. How does a cookie is read in JS? Answer: A cookie is read using JS. A cookie is nothing more than the value of another object, commonly known as the document cookie. You can obtain cookies by using this string. The same string maintains track of the name lists and can write cookies in several ways, including with a semicolon. A cookie typically consists of simply one value.

4. Q9. Name some of the JavaScript Frameworks Answer: Interview questions on JavaScript Frameworks A JavaScript framework is a JavaScript-based application framework. Its control flow makes it different from a JavaScript library. Although there are many JavaScript frameworks, these are some of the more popular ones: 1. Angular 2.React 3. Vue Q10. What will be the output of the following code? var Output = (function(x) { Delete X; return X; } )(0); console.log(output); Answer: The result would be ‘0’. You can remove properties from an object with the delete operator. Here, x is a local variable rather than an object. Local variables are unaffected by delete operators. If you run into any difficulties while using these JavaScript interview questions, please share your issues in the section below.