🧵 String Primitives vs String Objects in JavaScript – What’s the Difference?

In JavaScript, strings can be created in two different ways — as primitives or as objects. Although they may look similar, they behave differently under the hood. Understanding the distinction is crucial for writing clean and bug-free code.

🔹 What is a String Primitive?

A String primitive is the most common way to create a string in JavaScript. It’s created using single or double quotes.

const name = "Hari";
console.log(typeof name); // "string"

✅ Lightweight
✅ Fast
✅ Preferred way to handle text

🔹 What is a String Object?

A String object is created using the new String() constructor. It wraps the primitive string in an object.

const nameObj = new String("Hari");
console.log(typeof nameObj); // "object"

❌ Heavier
❌ Can lead to unexpected bugs
✅ Rarely needed

🔍 Key Differences

⚖️ Equality Pitfall

const primitive = "hello";
const object = new String("hello");

console.log(primitive == object);  // true
console.log(primitive === object); // false ❗

• == does type coercion → returns true
• === checks both type and value → returns false

🛠️ Auto-boxing Explained

Even though primitives are not objects, JavaScript temporarily wraps them with String objects to allow method access.

const msg = "hello";
console.log(msg.toUpperCase()); // "HELLO"

👉 Behind the scenes:

new String("hello").toUpperCase();

✅ Best Practice

Always use string primitives unless you have a very specific reason to use new String() (which is extremely rare).

📌 Conclusion

• Use string primitives: "name"
• Avoid string objects: new String("name")

They may seem the same, but small differences can lead to big bugs.