What does this log when an array is put on a constructor's prototype?

function Player(name) {
  this.name = name;
}
Player.prototype.items = [];
Player.prototype.score = 0;
 
const a = new Player("A");
const b = new Player("B");
 
a.items.push("sword");
a.score += 10;
 
console.log(b.items);
console.log(b.score, a.score);
console.log(Object.hasOwn(a, "items"), Object.hasOwn(a, "score"));