const users = [
    {
        name: 'A',
        age: 20,
        isAdmin: false,
    },
    {
        name: 'B',
        age: 15,
        isAdmin: true,
    },
    {
        name: 'C',
        age: 35,
        isAdmin: false,
    },
]

// 1) remove the age property from each object
// 2) add property isAdminUnder18 to each object (boolean)