javascript interview questions and answers for experienced pdf free download

javascript interview questions and answers for experienced pdf free download

Ans: Since 1is a string, everything is a string, so the result is Ans: Since 3and 4are integers, this is number arithmetic, since 7is a string, it is concatenation, so 77is the result. Ans: Code Collapse Copy Code. Ans: JavaScript 1. Ans: for, while, dowhileloops 22 What is an object in JavaScript, give an example? Ans: Both will call String constructor function Javascript You can confirm it by running the following statement: Interview.

Download console. CodeProject interviews Anders console. Hejlsberg andconsole. When comparing complex objects, they are equal only when they reference the same object i. Two variables containing identical objects are not equal to each other since they do not actually point at the same object.

Ans: Three dimensional array 30 Name any two JavaScript functions which are used to convert nonnumeric values into numbers? Ans: Yes! Javascript support automatic type conversion. You should take advantage of it, It is most common way of type conversion used by Javascript developers.

The program will stop executing code where the debugger keyword is applied in the program. Weakmap is similar to a collection of objects like a map. If the weak map object is set to a process, it considers each element as a key object and that key object will have a weak reference.

The applications written in JavaScript are known as JavaScript frameworks. These frameworks are a different form of JavaScript libraries and flows. Here is a list of some important frameworks, they are:. Espace characters are used to handle the special characters without breaking the code in javascript. It uses a black slash for different characters like single and double quotes, newline and so on.

Number objects help to represent the number of values to the variables. The values may be floating point or integer. Set objects are used to store different values to the elements. The values may be a reference or primitive values.

Ans: JavaScript 1. Ans: for , while , do - while loops. Give an example. Ans: Both will call String constructor function You can confirm it by running the following statement:. Many people think it to be complicated but in reality, it is very simple if one starts understanding it. It can be better understood as a number that is lower than any other number. Its properties are as follows: — A number of objects need not to be created to access this static property.

A function with the specific parameters is known as function declarations. To create a variable in JavaScript is called declarations.

Earlier in javascript, we use the var keyword for creating variables. Immutable variables are variables whose value is never changed in the complete life cycle of the program. Mutable variables are normal variables like var that can be changed any number of time. An arrow function is a consise and short way to write function expressions in Es6 or above. A rrow functions cannot be used as constructors and also does not supports this, arguments, super, or new.

It is best suited for non-method functions. Imports and exports help us to write modular javascript code. Using Imports and exports we can split our code into multiple files. Imports allow taking only some specific variables or methods of a file. We can import methods or variables that are exported by a module. See the below example for more detail. The module is a plain JavaScript object with an exports property.

Exports is a plain JavaScript variable that happens to be set to module. At the end of your file, node. A simplified way to view a JS file in Node could be this:. Strict mode also solves some mistakes that hamper the JavaScript engines to work efficiently. Strict mode can be enabled by adding the string literal "use strict" above the file. What is the way to get the status of a CheckBox? The status can be acquired as follows - alert document. How can the OS of the client machine be detected?

The navigator. Explain window. The onload function is not run until all the information on the page is loaded. This leads to a substantial delay before any code is executed.

This allows early manipulation of the code. How will you explain closures in JavaScript? When are they used? Closure is a locally declared variable related to a function which stays in memory when the function has returned. How can a value be appended to an array? A value can be appended to an array in the given manner - arr[arr. Explain the for-in loop? The for-in loop is used to loop through the properties of an object. Describe the properties of an anonymous function in JavaScript? A function that is declared without any named identifier is known as an anonymous function.

In general, an anonymous function is inaccessible after its declaration. What is the difference between. The function. On the other hand,. The basic difference between. Their usage can be illustrated by the given example. Define event bubbling? JavaScript allows DOM elements to be nested inside each other. In such a case, if the handler of the child is clicked, the handler of parent will also work as if it were clicked too.

Is JavaScript case sensitive? Give an example? Yes, JavaScript is case sensitive. For example, a function parseInt is not same as the function Parseint.

What boolean operators can be used in JavaScript? How can a particular frame be targeted, from a hyperlink, in JavaScript? This can be done by including the name of the required frame in the hyperlink using the 'target' attribute.

What is the role of break and continue statements? Break statement is used to come out of the current loop while the continue statement continues the current loop with a new recurrence. The code above will clear the existing array by setting its length to 0. This way of emptying the array also updates all the reference variables that point to the original array. The output would be 0. The delete operator is used to delete properties from an object.

Here x is not an object but a local variable. The main difference is the function foo is defined at run-time whereas function bar is defined at parse time. The output would be xyz. Here, emp1 object has company as its prototype property. You can test it console. However, we can delete the company property directly from theEmployee object using delete Employee. The trick of this question is that in the IIFE there are two assignments but the variable a is declared using the keyword var. What this means is that a is a local variable of the function.

On the contrary, b is assigned to the global scope. If strict mode was enabled, the code would raise the error Uncaught ReferenceError: b is not defined. Remember that strict mode requires you to explicitly reference to the global scope if this was the intended behavior.

So, you should write:. Stated in other words, the code above is equivalent to the following:. Yes JavaScript does support automatic type conversion, it is the common way of type conversion used by JavaScript developers. The parseInt function is used to convert numbers between different bases. Void 0 is used to call another method without refreshing the page. A function that is declared without any named identifier is known as an anonymous function.

In general, an anonymous function is inaccessible after its declaration. By default, the parsing of the HTML code, during page loading, is paused until the script has not stopped executing. It means, if the server is slow or the script is particularly heavy, then the webpage is displayed with a delay. This reduces the loading time of web pages and they get displayed faster. There is no scope for validation in innerHTML and, therefore, it is easier to insert rouge code in the document and, thus, make the web page unstable.

Unobtrusive JavaScript is basically a JavaScript methodology that seeks to overcome browser inconsistencies by separating page functionality from structure. Event delegation makes use of two often overlooked features of JavaScript events: event bubbling and the target element. This process is known as event bubbling; the event bubbles up from the originating element to the top of the DOM tree. The target element of any event is the originating element, the button in our example, and is stored in a property of the event object.

The tags that are provided the necessary information like alert to the browser for the program to begin interpreting all the text between the tags. The window. The downside to this is it might take a while before any code is actually executed.

Javascript is a scripting language supports scripts for Web pages but it is also used in non-browser environments as well. It is a powerful, lightweight, interpreted, scripting language with first-class functions i. That's the reason why it is widely used for the behavior of the web pages. We have listed some Javascript Jabascript interview questions with their answers that help you javascript interview questions and answers for experienced pdf free download crack javascript interviews. Javascript is an object-oriented computer programming language commonly used to create interactive effects within web browsers. In Javascript close abd is javacsript to close the current window. Javascript interview questions and answers for experienced pdf free download must write window. Closures are the combination exlerienced lexical environment and computer software books in urdu free download within which the function was declared. This allows JavaScript programmers to write better, more creative, concise and expressive codes. The closure will consist of all the local variables that were in-scope when the closure was created. Sure, closures appear to be complex and beyond the scope, but after you read this article, closures will be much more easy to understand and more simple for your everyday JavaScript programming tasks. In JavaScript, there is some experiended stuff that makes it the best of all. One of them is Delegation Model. When capturing and bubbling, allow functions to implement one single handler to many elements at one particular time then that is called event delegation. Event delegation allows you to add event listeners to one parent instead of specified nodes. javascript interview questions and answers for experienced pdf free download 1. What is JavaScript? JavaScript is a client-side as well as server side scripting language that can be inserted into HTML pages and is. 65 JavaScript Interview Questions and Answers – The ULTIMATE List (PDF Download). Posted by: Fabio Cimo in JavaScript December 30th. JavaScript Interview Questions for both Experienced Programmers and Freshers. 1) What is JavaScript? Ans:JavaScript is a scripting language. When you are interviewing for a javascript job, in addition to the basic interview questions you will be asked during a job interview, you will be asked more focused. This JavaScript interview questions blog will provide you an in-depth knowledge about JavaScript and prepare you for the interviews in Javascript Interview Questions | Advanced Technical Topics | For freshers & Professionals | Free Practice Test | Free Sample Resumes. In this blog, I have come up with the most frequently asked JavaScript interview questions and answers. Latest JavaScript Interview Questions and Answers PDF - CodeProject55 - Free download as PDF File .pdf), Text File .txt) or read online for free. of latest and updated JavaScript interview questions and their answers for freshers as well as. Tagged: javascript interview questions and answers pdf free download. Follow: PHP Interview Questions and Answers for freshers and experienced – We uploaded Javascript interview questions and answers in various downloadable formats like pdf, doc, zip etc. All these files are very easy to download with. In order to convert 4F of base 16 to integer, the code used will be - parseInt "4F", 16 ; How to disable an HTML object document. Use the "value" property. What is unshift method in JavaScript? Also the pop method take the last element off of the given array and returns it. Ajax uses asynchronous data transfer between the Browser and the web server. How to select an element by id and swapping an image? What is break and continue statements? If this activity does not load, try refreshing your browser. What type of environment are you looking to step into? How do you create a new object in JavaScript? How do you create array in javascript? Ans: Print third array element document. The Page object in ASP. Following are looping structures in Javascript: For While do-while loops javascript interview questions and answers for experienced pdf free download