Edit in JSFiddle

let obj = {
  name: {
    fName: 'Tony',
    lName: 'Stark',
    weaponNames: ['Lasers','Pulse Bolts','Energy Blade','Repulsor Rays']
  },
  age: 55,
  friends: [
		{ name: 'Peter Parker', character: 'Spider Man' },
    { name: 'Bruce Banner', character: 'Hulk' },
  ]
};

let clone = obj;
clone.name.weaponNames = ['Unibeam','Smart Missiles'];
clone.friends = [
		{ name: 'Steve Rogers', character: 'Captain America' },
		{ name: 'Natasha Romanoff', character: 'Black Widow' },
    { name: 'Clint Barton', character: 'Hawkeye' },
];


console.log(JSON.stringify(obj, null, 2));
console.log(JSON.stringify(clone, null, 2));