Update DataTypes.md

Author: aachal28

Notes/Basics/DataTypes.md

@@ -1 +1,48 @@
+# JavaScript Data Types 📚
 
+It defines the What kind of data that a variable can hold.
+
+JavaScript supports various data types, which can be classified into primitive and non-primitive types. 
+1. Primitive Data Types
+- These are the most basic data types in JavaScript.
+- They are immutable (cannot be changed).
+- They are passed by value.
+  
+2. NonPrimitive Data Types
+- These are more complex data types.
+- They are mutable (can be changed).
+- They are passed by reference.
+
+Here's an overview: 👇
+
+## Primitive Data Types
+
+| Data Type  | Description                                       | Example           |
+|------------|---------------------------------------------------|-------------------|
+| Number     | Represents numeric values                        | `let num = 42;`   |
+| String     | Represents sequences of characters                | `let str = "Hello";` |
+| Boolean    | Represents a logical value (true or false)        | `let bool = true;` |
+| Undefined  | Represents a variable that hasn't been assigned a value | `let undef;` |
+| Null       | Represents the intentional absence of any value   | `let nul = null;` |
+
+## Non-Primitive Data Types
+
+| Data Type  | Description                                       | Example                         |
+|------------|---------------------------------------------------|---------------------------------|
+| Object     | Represents a collection of key-value pairs        | `let obj = { key: "value" };`  |
+| Function   | A special type of object that is callable         | `function func() {}`           |
+
+## Other Data Types
+
+JavaScript also has other data types, such as `Symbol` and `BigInt`, which are less commonly used in everyday programming tasks.
+
+## Usage of `typeof`
+
+You can use the `typeof` operator to determine the data type of a value or variable:
+
+`Example`
+
+```javascript
+let num = 42;
+console.log(typeof num); // Output: "number"
+```