I encountered a bug in Javascript that took me hours to realize. The way I see it logically: The object after receiving the value had nothing to do with the array but it changes as the array changes. Please explain the interaction, I am new to Javascript. Thank you so much!

const x = [[1,5],[2],[3]];
const y = {change:[]};
y.change.unshift(x[0]);
console.log(y); //{ change: [ [ 1, 5 ] ] }
x[0][1] = 10;
console.log(y); // { change: [ [ 1, 10 ] ] }