What is the difference between null and undefined in JavaScript?
Ava W

In JavaScript,null andundefined are two distinct values used to represent different concepts. Let's explore the differences between them: 1.undefined: -undefined is a primitive value that is automatically assigned to variables that have been declared but have not been assigned a value. - It indicates the absence of a value or the uninitialized state of a variable. - It is the default value for function parameters that have not been provided. -undefined is a type in JavaScript and represents an undefined value. - When accessing an object property or array element that does not exist, the result isundefined. - Here's an example:

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     var x;
     console.log(x); // Output: undefined

     function example(a) {
       console.log(a); // Output: undefined
     }
     example();

2.null: -null is also a primitive value that represents the intentional absence of any object value. - It is used to explicitly indicate that a variable or object property has no value or is empty. - Unlikeundefined,null is a value that needs to be assigned explicitly. - It can be used to clear the value of an object property or to indicate that a variable is intentionally empty. -null is considered an object type in JavaScript, even though it is a primitive value. - Here's an example:

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     var x = null;
     console.log(x); // Output: null

     var obj = { name: null };
     console.log(obj.name); // Output: null

3. Comparison: - When comparingnull andundefined using loose equality (==), they are considered equal to each other and to no other value. - However, when using strict equality (===),null andundefined are not considered equal, as they have different types. - Here's an example:

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     console.log(null == undefined); // Output: true
     console.log(null === undefined); // Output: false

In summary,undefined is used to indicate the absence of a value, uninitialized variables, or when accessing non-existent object properties or array elements. On the other hand,null is used to explicitly indicate the intentional absence of an object value or an empty variable or property. Although they are often used interchangeably, they have different meanings and behaviors in JavaScript.

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