NULL in Javascript
A variable is a storage location that contains a value. A null represents nothing . Its not an actual value. It means that the storage location does not contain anything (but null itself is just a special kind of value).What's the typeof null?
typeof null // "object"
The null value is technically a primitive , the way "object" or "number" are primitives. This would typically mean that the type of null should also be "null". However, this is not the case because of a peculiarity with the way JavaScript was first defined.
Why is null considered an object in JavaScript?
Actually null is not an object , it is a primitive value. For example, you cannot add properties to it. Sometimes people wrongly assume that it is an object, because typeof null returns "object". It is a JavaScript design error they can't fix now (that might even be fixed in ECMAScript 6). It should have been type null , not type object, or not have it at all. It necessitates an extra check (sometimes forgotten) when detecting real objects and is source of bugs.
Related Topics
- JavaScript Interview Questions (Part2)
- JavaScript Interview Questions (Part3)
- Is JavaScript a true OOP language?
- Advantages and Disadvantages of JavaScript
- Difference Between JavaScript and ECMAScript?
- What is noscript tag?
- Escaping Special Characters in JavaScript
- What is undefined x 1 in JavaScript?
- JavaScript : Logical Operators
- Difference between '=', '==' and '===' operators?
- How to reload a page using JavaScript?
- How to write html code dynamically using JavaScript?
- How to add html elements dynamically with JavaScript?
- How to load another html page from javascript?
- What Is The Disadvantages Using InnerHTML In JavaScript?
- What is Browser Object Model
- How to detect the OS on the client machine in JavaScript?
- Difference between window, document, and screen in Javascript?
- Difference between the substr() and substring() in JavaScript?
- How to replace all occurrences of a string in JavaScript?
- How to test a string as a literal and as an object ?
- What is Associative Array? How do we use it?
- What is an anonymous function in JavaScript?
- What is the use of 'bind' method in JavaScript?
- Pure functions Vs. Impure functions in javascript
- Is Javascript a Functional Programming Language?
- What's the Difference Between Class and Prototypal Inheritance?
- Javascript, Pass by Value or Pass by Reference?
- How to prevent modification of an object in Javascript?
- What is 'this' keyword in JavaScript?
- How Does Function Hoisting Work in JavaScript?
- What does the delete operator do in JavaScript?
- What is the Infinity property used for in Javascript?
- Event bubbling and Event Capturing in JavScript?
- What is "strict mode" and how is it used in JavaScript?
- What is the difference between .call() and .apply()?
- Entire content of a JavaScript source file in a function block?
- What is an immediately-invoked function expression?
- What is escape & unescape String functions in JavaScript?
- What is the instanceof operator in JavaScript?
- What Are RESTful (REpresentational State Transfer)Web Services?
- What is Unobtrusive JavaScript & Why it's Important?
- What Does JavaScript Void(0) Mean?
- What are JavaScript Cookies?
- Difference between Client side JavaScript and Server side JavaScript
- TypeError: document.getelementbyid(...) is null
- Uncaught TypeError: Cannot read property of undefined In JavaScript
- What's the difference between Null and Undefined?