JS Practice — Built-in Objects

String() vs new String() — primitive vs object

📖 Usage Example

String(42)         // → '42'
String(true)       // → 'true'
String(null)       // → 'null'
String(undefined)  // → 'undefined'

Use String() to safely convert any value to its string representation.

String Primitive vs String Object

String(value) returns a primitive string. new String(value) returns a String object (rarely used).

Challenge: Implement isPrimitiveString(val) that returns true when val is a primitive string (not a String object).

isPrimitiveString(String('hi'))     // → true
isPrimitiveString(new String('hi')) // → false

💡 Hints (2)