如何修復 React：'變量'未定義 no-undef

Question

我剛剛開始學習反應我被困在這個問題上我已經創建了一個數組費用。 聲明沒有問題，但在使用時會拋出錯誤。

import ExpenseItem from "./components/ExpenseItem";
function App() {
const expenses = [
{
  id: "e1",
  title: "Toilet Paper",
  amount: 94.12,
  date: new Date(2020, 7, 14),
},
{ 
  id: "e2", 
  title: "New TV", 
  amount: 799.49,
  date: new Date(2021, 2, 12) 
 },

]; return (
<div>
  <h2>Let's get started!</h2>
  <ExpenseItem
    title={expenses[0].title}
    amount={expense[0].amount}
    date={expense[0].date}
  ></ExpenseItem>
  <ExpenseItem
    title={expenses[1].title}
    amount={expense[1].amount}
    date={expense[1].date}
  ></ExpenseItem>
</div>
    );
     }
   export default App;

錯誤日志是：

 src\App.js
 Line 23:17:  'expense' is not defined  no-undef
 Line 24:15:  'expense' is not defined  no-undef
 Line 28:17:  'expense' is not defined  no-undef
 Line 29:15:  'expense' is not defined  no-undef

Answer 1

看起來你拼錯了expenses ，而是在你的ExpenseItem元素中寫了expense 。 修正錯字應該修正你的代碼。

Answer 2

function 應用程序應該返回：

return (
<div>
  <h2>Let's get started!</h2>
  <ExpenseItem
    title={expenses[0].title}
    amount={expenses[0].amount}
    date={expenses[0].date}
  ></ExpenseItem>
  <ExpenseItem
    title={expenses[1].title}
    amount={expenses[1].amount}sa
    date={expenses[1].date}
  ></ExpenseItem>
</div>
);