// Initialize items as a Map
let items = new Map([
["uuid-1", { id: "uuid-1", title: "Item 1" }],
["uuid-2", { id: "uuid-2", title: "Item 2" }],
["uuid-3", { id: "uuid-3", title: "Item 3" }],
]);
// Delete item with id "uuid-2"
const deleteId = "uuid-2";
const deletedItem = items.get(deleteId); // Get the item to be
deleted (for logging)
items.delete(deleteId); // Delete the item from the Map
console.log(deletedItem); // Log the deleted item
console.log(Array.from(items)); // Convert Map to Array to log remaining items
// modify item with id "uuid-3"
const modifyId = "uuid-3";
const modifiedItem = items.get(modifyId); // Get the item to be modified (for logging)
items.set(modifyId, { ...modifiedItem, title: "Modified Item 3" });
// Modify the item in the Map
console.log(modifiedItem); // Log the modified item
console.log(Array.from(items)); // Convert Map to Array to log remaining items
// Add a new item
const newItem = { id: "uuid-4", title: "Item 4" }; // Create a new item
items.set(newItem.id, newItem); // Add the new item to the Map
console.log(Array.from(items)); // Convert Map to Array to log all items
// MAP IS IMMUTABLE
// Original items Map
const items = new Map([
["uuid-1", { id: "uuid-1", title: "Item 1" }],
["uuid-2", { id: "uuid-2", title: "Item 2" }],
["uuid-3", { id: "uuid-3", title: "Item 3" }],
]);
// Immutable Delete
const deleteId = "uuid-2";
const itemsAfterDelete = new Map([...items].filter(([key, _]) => key !== deleteId));
// Immutable Modify
const modifyId = "uuid-3";
const modifiedItem = { ...items.get(modifyId), title: "Modified Item 3" };
const itemsAfterModify = new Map([...itemsAfterDelete]
.map(([key, value]) => key === modifyId ? [key, modifiedItem] : [key, value]));
// Immutable Add
const newItem = { id: "uuid-4", title: "Item 4" };
const itemsAfterAdd = new Map([...itemsAfterModify, [newItem.id, newItem]]);
// Logging for demonstration
console.log(Array.from(items)); // Original items Map remains unchanged
console.log(Array.from(itemsAfterDelete)); // Items after deletion
console.log(Array.from(itemsAfterModify)); // Items after modification
console.log(Array.from(itemsAfterAdd)); // Items after adding a new item