JS Practice — Built-in Objects

hasOwnProperty() — after delete

📖 Usage Example

// Check for own (non-inherited) property
const obj = { a: 1 }
obj.hasOwnProperty('a')          // → true
obj.hasOwnProperty('toString')   // → false

Use hasOwnProperty() to check whether a property exists directly on an object rather than on its prototype chain.

hasOwnProperty() — after delete

Once a property is deleted with the delete operator, hasOwnProperty() returns false for it.

Challenge: Delete a property and verify it's gone using hasOwnProperty().

💡 Hints (1)