create CRUD functions for UserAPI class

src/index.ts

@@ -1,2 +1,104 @@
-console.log("TEST")
-console.log("HI AARON!")
+
+// user object has these fields
+// id (optional)
+// name
+// age
+// color
+
+// -create a class called UserAPI
+// it has a class property called users, which is just a map {}
+// add the following functions to the class, using es6 syntax (arrow functions)
+// 1. getUser by id (eg. getUser = (id)=  > { return ...})
+// 2. getUsers (returns all users in array)
+// 3. createUser has argument of user object {}. Make sure to assign an id property to the user object
+// 4. deleteUser by id
+// 5. updateUser has argument of user object {}
+
+// each of the functions will manipulate / access the users class property
+// use immutability via the spread operator:  { ...user, id: "myID" }
+// show that these operations work by creating an instance of your class, and calling the methods
+// and console logging the output
+
+// const myApi = new UserApI()
+// myApi.xxx()
+
+class UserAPI {
+  constructor() {
+    this.users = {};
+  }
+
+  getUsers = () => Object.values(this.users);
+
+  getUserById = (id) => {
+    return this.users[id];
+  };
+
+  createUser = (user) => {
+    const users = this.users;
+    const newId = () => {
+      if (Object.keys(users).length === 0) {
+        return 1;
+      } else {
+        let max = Math.max(...Object.keys(users));
+        return max + 1;
+      }
+    };
+    const userWithId = { ...user, id: newId() };
+    this.users = { ...this.users, [newId()]: userWithId };
+    return userWithId;
+  };
+
+  updateUser = (user) => {
+    this.users = { ...this.users, [user.id]: user };
+    return user;
+    //use spread operator to update by key
+  };
+
+  deleteUser = (id) => {
+    const { [id]: user, ...updatedUsers } = this.users;
+    this.users = updatedUsers;
+  };
+}
+
+const myApi = new UserAPI();
+
+const userOne = {
+  id: null,
+  name: "hank",
+  age: 7,
+  color: "orange",
+};
+
+const userTwo = {
+  id: null,
+  name: "rob",
+  age: 5,
+  color: "green",
+};
+
+const userThree = {
+  id: null,
+  name: "elbert",
+  age: 8,
+  color: "blue",
+};
+
+const userThreeUpdate = {
+  id: 3,
+  name: "elbert",
+  age: 9,
+  color: "blue",
+};
+
+console.log(myApi.createUser(userOne));
+console.log(myApi.createUser(userTwo));
+console.log(myApi.createUser(userThree));
+console.log(myApi.getUsers());
+console.log(myApi.getUserById(1));
+console.log(myApi.updateUser(userThreeUpdate));
+console.log(myApi.getUsers());
+console.log(myApi.deleteUser(1));
+console.log(myApi.getUsers());
+
+
+