1 var person = {
2        name: "Harry",
3        age: 16,
4        gender: "Male"
5    };
6    
7    // Deleting a property completely
8    delete person.age;
9    alert(person.age); // Outputs: undefined
10    console.log(person); // Prints: {name: "Harry", gender: "Male"}

1var ourDog = {
2  "name": "Camper",
3  "legs": 4,
4  "tails": 1,
5  "friends": ["everything!"],
6  "bark": "bow-wow"
7};
8
9delete ourDog.bark;

1// ES6 should be in search keyword
2Reflect.deleteProperty(myObj, propNameString);
3// Source referece in Chinese.

1var person = {
2  firstName:"John",
3  lastName:"Doe",
4  age:50,
5  eyeColor:"blue"
6};
7
8delete person.age;  // or delete person["age"];
9
10// Before deletion: person.age = 50, after deletion, person.age = undefined
11