JavaScript Primitives and Objects

Introduction

• Difference between primitive data types and objects in JavaScript.

Primitive Data Types

• Fundamental, built-in data types in JavaScript.
• 7 Primitive Data Types: NN BB SS U
  • NN : Null, Number
  • BB : Boolean, BigInt
  • SS : String, Symbol
  • U: Undefined
• Purpose of Data Types: The type of content that can be stored in a variable, e.g., strings, numbers.

Examples of Primitive Data Types:

• Declaration examples: let a = null; let b = 42; // number let c = true; // boolean let d = BigInt(567); // BigInt let e = "Harry"; // string let f = Symbol("I am a nice symbol"); // symbol let g = undefined; // undefined
• Console Logging: console.log(a, b, c, d, e, f, g);
• Type Checking: console.log(typeof d); // BigInt
• null vs undefined:
  • null: Explicitly signifies no value.
  • undefined: Default state of a variable that has not been assigned a value.

Non-Primitive Data Types

• Objects: Key-value pairs.
• Key: Simple strings or numbers.
• Value: Any data type.

Object Example

• Creation and Usage: const item = { "Harry": true, "Shubh": false, "Lovish": 67, "Rohan": undefined }; console.log(item["Harry"]); // true console.log(item["Rohan"]); // undefined console.log(item["Shubh"]); // false
• Use Cases:
  • Mapping student marks, item prices, student-classroom assignments.
  • Easy value lookup using keys.

Conclusion

• Two Types of Data Types in JavaScript:
  • Primitive: NN BB SS U
  • Non-Primitive: Object
• Importance of understanding data types for JavaScript mastery.

Next Steps: More detailed exploration of symbols and BigInt in future videos.