# 5.4 鍵盤相關事件

## 通常用在表單欄位上

* focus：欄位取得焦點之後觸發。
* blur：欄位失去焦點之後，會觸發。
* change：新資料與原資料，不一樣時，會觸發。
* keydown：鍵盤按下去的狀態，會觸發。
* keyup：鍵盤按下去時放開的狀態，會觸發。
* input：資料有異動時，會觸發。

## 範例：鍵盤常用事件

HTML：

```markup
<input type="text" id="text_input">
```

範例：

{% embed url="<https://codepen.io/carlos411/pen/dyMNJdJ>" %}


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