Ten typical JavaScript interview questions and their responses are provided below:
1. First, what is a script written in Java?
A client-side programming language called JavaScript is used to give web pages interaction.
2. Can you explain the distinction between Java and JavaScript?
Java is a programming language, whereas JavaScript is a scripting language. They are unrelated and have separate use cases and syntax.
3. Describe JavaScript hoisting in detail.
Hoisting is a JavaScript behavior in which, at compilation time, function and variable declarations are pushed to the top of their contained scope.
4. What do JavaScript closures mean?
Functions known as closures can access variables from their external, enclosing lexical context even after the outer function has terminated.
5. What does a JavaScript event loop do?
JavaScript employs the event loop as its asynchronous operation handling mechanism. It makes handling events, callbacks, timers, and other asynchronous activities in JavaScript more effective.
6. In JavaScript, what are arrow functions?
In JavaScript, anonymous functions may be written with ease using the arrow functions syntax. The "this" keyword is lexically bound, and their syntax is shorter.
7. What distinguishes "null" from "undefined"?
A basic JavaScript value called "Undefined" is applied to variables that have been declared but not yet given a value. Although it is also a primitive value, "Null" is expressly set to a variable by the developer to indicate the purposeful lack of an object value.
8.Describe the JavaScript prototype concept.
In JavaScript, prototypes are used for object inheritance. Every object has a prototype that it derives its methods and attributes from; this prototype might be shared by several objects.
9. What kinds of data exist in JavaScript?
The six primitive data types available in JavaScript are text, numeric, boolean, undefined, null, and symbol. Object is the only non-primitive data type it possesses.
10. In JavaScript, how can one determine whether a variable is an array?
The Array.isArray() function may be used to determine whether a variable is an array.
For example:
```javascript
const arr = [1, 2, 3];
console.log(Array.isArray(arr)); // Output: true
```
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