React 새로운 배열 추가하기

App.js

import React, { useRef, useState } from "react";
import Hello from "./Hello.js";
import "./App.css";
import Wrapper from "./Wrapper.js";
import Counter from "./Counter.js";
import InputSample from "./InputSample.js";
import UserList from "./UserList.js";
import CreateUser from "./CreateUser.js";

function App() {
  const [inputs, setInputs] = useState({
    username: "",
    email: ""
  });
  const { username, email } = inputs;
  const onChange = e => {
    const { name, value } = e.target;
    setInputs({
      ...inputs,
      [name]: value
    });
  };
  const [users, setUsers] = useState([
    {
      id: 1,
      username: "velopert",
      email: "public.velopert@gmail.com"
    },
    {
      id: 2,
      username: "tester",
      email: "tester@example.com"
    },
    {
      id: 3,
      username: "liz",
      email: "liz@example.com"
    }
  ]);

  const nextId = useRef(4);
  const onCreate = () => {
    const user = {
      id: nextId.current,
      username,
      email
    };
    setUsers([...users, user]);

    setInputs({
      username: "",
      email: ""
    });
    nextId.current += 1;
  };
  return (
    <>
      <CreateUser
        username={username}
        email={email}
        onChange={onChange}
        onCreate={onCreate}
      />
      <UserList users={users} />
    </>
  );
}

export default App;

CreateUser.js

import React from "react";

//4가지의 props를 받아옴
function CreateUser({ username, email, onChange, onCreate }) {
  return (
    <div>
      <input
        name="username"
        placeholder="계정명"
        onChange={onChange}
        value={username}
      />
      <input
        name="email"
        placeholder="이메일"
        onChange={onChange}
        value={email}
      />
      <button onClick={onCreate}>등록</button>
    </div>
  );
}

export default CreateUser;

 

출처 : 벨로퍼트님의 강의 예제입니다.