JavaScript 常數

使用 const 我們仍然可以修改 Javascript 物件的內容，但對該物件的引用將是不可變的。

const product = {name: "Sugar", weight: "1 kg"};
product.name = "Some New Name";

console.log(product);

{
  name: "Some New Name",
  weight: "1 kg"
}

JavaScript 凍結

在我們不想修改物件內容的情況下，首選使用凍結。

const product = {name: "Sugar", weight: "1 kg"};
Object.freeze(product);
product.name = "Some New Name";

console.log(product);

{
  name: "Sugar",
  weight: "1 kg"
}