Hash Tables & JavaScript Objects

const table = new Map();
const key1 = { id: 1 };
const key2 = { id: 1 };
table.set(key1, 'value1');
console.log(table.get(key2));

'value1'
undefined
The code outputs undefined because: 1) Map uses reference equality for object keys, 2) key1 and key2 are different objects despite same content, 3) Object literals create distinct references, 4) Map.get() uses strict equality comparison, 5) Different references are treated as different keys, 6) Common source of confusion in Map usage, 7) Important consideration for object keys, 8) Different from value equality in some other languages.
null
Error