如果您想獲取所有更改（添加、刪除、更新和未更改）以及檢查對象的多個鍵，您也可以嘗試類似的操作。
時間復雜度為 O(N)，空間復雜度為 O(N)。假設“id”是唯一的。
function getProductChanges(oldProductsList, newProductsList) {
let oldProductsMap = {};
let newProductsMap = {};
let addedProductsList = [];
let updatedProductsList = [];
let removedProductsList = [];
let unchangedProductsList = [];
// considering id is unique
// creating map for old products list
oldProductsList.map((oldProduct) => {
oldProductsMap[oldProduct.id] = oldProduct;
});
// creating map for new products list and
// filtering newly added, updated and unchanged products list
newProductsList.map((newProduct) => {
newProductsMap[newProduct.id] = newProduct;
let oldProduct = oldProductsMap[newProduct.id];
if (oldProduct) {
// if an existing product is updated
if (JSON.stringify(oldProduct) !== JSON.stringify(newProduct)) {
updatedProductsList.push(newProduct);
} else {
unchangedProductsList.push(newProduct);
}
}
else {
// if a new product is added
addedProductsList.push(newProduct);
}
});
// populating removedProductsList
removedProductsList = oldProductsList.filter((oldProduct) => !newProductsMap[oldProduct.id]);
return {
added: addedProductsList,
updated: updatedProductsList,
removed: removedProductsList,
unchanged: unchangedProductsList,
};
}
輸入：
let products = [
{ id: "A32S", title: "Car" },
{ id: "D12E", title: "Rabbit" },
{ id: "A321", title: "Ghost" },
{ id: "A320", title: "Lion" },
];
let newProducts = [
{ id: "A32S", title: "Ferrari" },
{ id: "D12E", title: "Rabbit" },
{ id: "A321", title: "Ghost" },
{ id: "A322", title: "Zebra" },
];
console.log(getProductChanges(products, newProducts));
輸出：
{
added: [{ id: "A322", title: "Zebra" }],
removed: [{ id: "A320", title: "Lion" }],
unchanged: [
{ id: "D12E", title: "Rabbit" },
{ id: "A321", title: "Ghost" },
],
updated: [{ id: "A32S", title: "Ferrari" }],
}
