javascript unset

hello = document.getElementById("Hello")
delete hello

let monTableauAssociatif = {
     'prenom' : 'Mark' ,
     'nom'    : 'Zuckerberg' , 
     'poste'  : 'Pdg de Facebook',

 } ;
 delete(monTableauAssociatif.poste)
 console.log(monTableauAssociatif) ;

var person = {
  firstName:"John",
  lastName:"Doe",
  age:50,
  eyeColor:"blue"
};

delete person.age;  // or delete person["age"];

// Before deletion: person.age = 50, after deletion, person.age = undefined