javascript - 如何使用reducer将对象添加到数组中

Question

//我需要使用通讯录的reducer将对象添加到数组中

// reducer

const addContact = (contacts = [], action) => {
  let contactsArr = [{}];
  if (action.type = "ADD_CONTACT") {
    return [...contactsArr, action.payload];
  }
  return contacts;
};

Action

export const addContactRed = contact => {
  return {
    type: "ADD_CONTACT",
    payload: contact
  };
};


{
type:"ADD_CONTACT",
payload:{name:"xyz",phonenum:10101001}
}

{
type:"ADD_CONTACT",
payload:{name:"abc",phonenum:0101001}
}

//分派(dispatch)两个 Action 后，我想要的最终数组是

//contactsArr

[
{name:"xyz",phonenum:10101001},
{name:"abc",phonenum:0101001}
]

Answer 1

你不需要太多的 init let contactArr = [{}];它将重置您的 reducer 中的存储值。只需使用联系人存储变量

const addContact = (contacts = [], action) => {
 // if (action.type = "ADD_CONTACT") {
  if (action.type === "ADD_CONTACT") {
    return [...contacts, action.payload];
  }
  return contacts;
};