1. 数组(Array)
1. 数组(Array)
示例场景:显示一个待办事项列表,并允许用户添加新的待办事项。
import React, { useState } from "react";
function TodoList() {
const [todos, setTodos] = useState(["学习React", "练习算法"]);
const [inputValue, setInputValue] = useState("");
const handleAddTodo = () => {
if (inputValue.trim()) {
setTodos([...todos, inputValue]);
setInputValue("");
}
};
return (
<div>
<ul>
{todos.map((todo, index) => (
<li key={index}>{todo}</li>
))}
</ul>
<input
type="text"
value={inputValue}
onChange={(e) => setInputValue(e.target.value)}
/>
<button onClick={handleAddTodo}>添加</button>
</div>
);
}
export default TodoList;