In JavaScript, both `null` and `undefined` are primitive values, not objects. Despite the fact that they are often mistakenly referred to as objects, they are distinct primitive data types.
`null`:
Type: `null` is a primitive value.
Use Case: It is often used to explicitly represent the absence of any object value or no value.
Example:
let myVar = null;
`undefined`:
Type: `undefined` is a primitive value.
Use Case: It is typically the default value assigned to a variable that has been declared but not initialized with a value.
Example:
let myVar;
Difference:
1. Assignment:
- `null` is often assigned explicitly to represent the absence of a value.
- `undefined` is often the default value assigned by JavaScript when a variable is declared but not initialized.
2. Usage:
- `null` is commonly used by developers to indicate intentional absence of a value.
- `undefined` is often automatically assigned by JavaScript in certain situations, such as when accessing an uninitialized variable or when a function does not return a value.
3. Typeof Operator:
- The `typeof` operator returns the string "object" for `null`.
- The `typeof` operator returns the string "undefined" for `undefined`.
Example:
console.log(typeof null); // Outputs: "object"console.log(typeof undefined); // Outputs: "undefined"
Despite these differences, both `null` and `undefined` represent the absence of a meaningful value in JavaScript, and developers use them in different contexts based on their specific use cases.
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