Strings in JavaScript are one of the primitive data types, alongside numbers, booleans, null, undefined, bigint, and symbols. Unlike objects, primitives do not have methods or properties of their own. However, when you attempt to call a method or access a property on a string, JavaScript automatically wraps the string in a String object to provide access to methods.

let s = "hello";
console.log(typeof s);  
console.log(s.length);  

// Example with a number
let x = 42;
console.log(x.toString()); 

// Example with a boolean
let y = true;
console.log(y.toString());

/* Internal Working of primitives
   to be treeated as objects
   
// Temporary wrapper object
let temp = new String("hello"); 

console.log(temp.length); // 5

// The wrapper is discarded after use
temp = null; */

string
5
42
true

The String Object

JavaScript has a built-in String object that can be explicitly used to create string objects. This is different from primitive strings.

const s = new String("Hello");

console.log(typeof s);

object

Key Differences Between Primitives and String Objects

Tip: Always prefer primitive strings for simplicity and performance.

Why the Confusion?

The confusion arises because strings appear to have methods and properties like objects, but they are primitives. The temporary wrapping of primitives into String objects is what enables this behavior.

const s = "Test";
console.log(s.constructor === String);

true

Here, JavaScript implicitly wraps the string in a String object to access the .constructor property.