Copying Objects

Build a new object from existing fields.

copy_object.js

const quantity = 3;
const copied = JSON.stringify({
  ...{ item: "book" },
  quantity: quantity,
});
const label = "quantity=" + quantity;

console.log("copied=" + copied);
console.log("label=" + label);

copy-object Object spread copies fields into a new object. Later fields can add new values without mutating the original shape.