Question:

Describe and demonstrate the function of the delete keyword in deleting object properties.

The delete keyword is used in JavaScript to delete object properties. For example:

 var person = {
 name: "Oscar",
 age: 27
};

delete person.name;

// outputs: { age: 27}
console.log(person);

You can not delete ordinary variables with the delete operator.

var man = "Batman";

delete man;

//outputs : "Batman"
console.log(man);

You can delete global variables however because their part of the window global object.

 justiceLeague = "Cyborg"; // since var left out becomes property of window
 
 delete window.justiceLeague
 
 // ReferenceError: justiceLeague not defined
 console.log(justiceLeague)

And there is also a return value for the delete operator. This value is either true or false. Here we get the return of true but a false value may happen because of the property being unwritable.

 var person = {
 name: "Oscar",
 age: 27
};

var nameDeleted = delete person.name;

// outputs: true
console.log(nameDeleted);

Use the delete operator whenever you need to remove a property from an object and that’s about everything you need to know about this operator.