Source: Difference between null and undefined in JavaScript
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In JavaScript, `null` and `undefined` are two distinct primitive values that represent the absence of a meaningful value. Although they are similar in some ways, they have subtle differences. Here’s a breakdown of the differences between `null` and `undefined`:
- Assignment: `undefined` is a default value assigned to a variable that has been declared but has not been assigned a value. On the other hand, `null` is a value that can be assigned explicitly to a variable by the programmer to indicate the absence of an object or an empty value.
- Type: `undefined` is a type itself in JavaScript and represents the absence of a value. It is considered a primitive value. On the other hand, `null` is an object type, which means it is an empty object reference.
- Usage: `undefined` is commonly used to indicate the absence of a value, such as when a variable has not been assigned a value or when a function does not return a value explicitly. `null`, on the other hand, is typically used to indicate the intentional absence of an object or value.
- Behavior: When you try to access a variable that has been declared…