---
# System prepended metadata

title: "\U0001F3C5 Day 04 - 型別陷阱題"
tags: [2025 Node.js 後端工程師培訓營]

---

# 🏅 Day 04 - 型別陷阱題

### 題目

以下題目請合併為一份 CodePen 繳交，並透過「註解」進行回答。

問題
---
以下變數 a, b, c, d 它們的值、型別各自為何？ 
( 請先想想看，不要用 console.log 檢查 ᕙ( ˙-˙ )ᕗ )

```jsx=
let a = true + true ;
let b = false + 123 ;
let c = null + 123 ;
let d = null + '123';
```

範例回答格式：
```javascript=
// a = 值, 型別
// b = 值, 型別
```


## 回報流程

將答案寫在 CodePen 並複製 CodePen 連結貼至底下回報就算完成了喔! 
解答位置請參考下圖（需打開程式碼的部分觀看）

![](https://i.imgur.com/vftL5i0.png)

<!-- 解答：  

a = 2, number
b = 123, number
c = 123, number
d = 'null123', string

補充文章：https://ithelp.ithome.com.tw/articles/10191180
-->




回報區
---
| #   | Discord | CodePen / 答案 |
| -------- | -------- | -------- |
| 1   | 不好說 | [Codepen](https://codepen.io/zarr12steven/pen/pvzawwq) |
| 2   | Sui | [Codepen](https://codepen.io/suihsilan/pen/RNbQgXQ?editors=0010) |
| 3.  | HarryKuo |[Codepen](https://codepen.io/harry_kuo/pen/azoqyBW?editors=0011) |
| 4.  | 馬德 |[Codepen](https://codepen.io/maywang/pen/qEWxXmV?editors=0010) |
| 5.  | helena |[Codepen](https://codepen.io/helena27/pen/dPbdzKj?editors=1011) |
| 6.  | Tau |[Codepen](https://codepen.io/Tau-Hsu/pen/GgKQvBe?editors=0011) |
| 7.  | ss585801. |[Codepen](https://codepen.io/ss585801/pen/yyBvowg?editors=0012) |
| 8.  | Benson |   [Codepen](https://codepen.io/DevilButler/pen/jENZGNM?editors=0011) | 
| 9.  |ZoeKang|[CodePen](https://codepen.io/byehywmx-the-animator/pen/mybXBmd?editors=0011)
| 10. |poyi|[CodePen](https://codepen.io/poyi-the-flexboxer/pen/wBwyrWG?editors=0012)
| 11. |pja._.|[Codepen](https://codepen.io/PJA0103/pen/ZYzrXpa?editors=1010)
| 12. |Nora|[Codepen](https://codepen.io/ehguhcmy-the-reactor/pen/gbYvXWx?editors=1111)
| 13. |hsiang4100|[Codepen](https://codepen.io/vvnrbgxl-the-typescripter/pen/jENZamv?editors=0010)|
| 14. |adengg|[Codepen](https://codepen.io/Osases/pen/LEPQOdR?editors=0012)|
| 15. |Lee|[Codepen](https://codepen.io/leemo-tseng/pen/azoqVem)|
| 16. |JerryOOO|[Codepen](https://codepen.io/fatiangel/pen/VYZQQWJ?editors=0011)|
| 17. |Ali|[Codepen](https://codepen.io/Alicia1117/pen/YPKeayq)|
| 18. |Xuan|[Codepen](https://codepen.io/YiXuan-Chen-the-vuer/pen/OPLQvPg)|
| 19. |JC|[Codepen](https://codepen.io/lifetimingwhisper/pen/ZYzroEY)|
| 20. |Tammy|[Codepen](https://codepen.io/Tammy_Tsai/pen/raBJvBO) | 
| 21. |yutzu|[Codepen](https://codepen.io/dtafsrmf-the-lessful/pen/zxORjLz?editors=0010) | 
| 22.   | 柴郡貓 | [Codepen](https://codepen.io/cssf998811/pen/wBwyxar?editors=0010)|
| 23.   | potato_17859 | [CodePen](https://codepen.io/Girl-Lee/pen/JoPpBEo?editors=0010) |
| 24.   | 佩妮 | [CodePen](https://codepen.io/pen/?editors=0011) |
| 25.   | CC(tofuuu_cat) | [CodePen](https://codepen.io/CC-cat/pen/QwLQVmw?editors=0010) |
| 26.   | jameschen5522 | [CodePen](https://codepen.io/frswsqve-the-selector/pen/raBJqmd?editors=0010) |
|27.|-----這條線以下都麻糬-----|[Codepen](https://codepen.io/tsfaydhk-the-selector/pen/YPKeJZb?editors=0012)|
|28.|weins_jo3jo3|[Codepen](https://codepen.io/Shao-the-selector/pen/gbYvQjo?editors=0010)|
|29.|Jayhsu|[Codepen](https://codepen.io/Jay-Hsu-the-bold/pen/wBwyNOJ?editors=1111)| 
|30.|Wayne_957|[Codepen](https://codepen.io/Wayne957/pen/dPbdEWr?editors=0011)
| 31  | ally_tsao           | [Codepen](https://codepen.io/ggnhmrxv-the-scripter/pen/XJrZwaq?editors=0011)|
| 32 |地呱  |[Codepen](https://codepen.io/wiibxzdw-the-bold/pen/dPbdBvG?editors=0011) |
| 32 |shiang  |[Codepen](https://codepen.io/shiang29/pen/bNbLXYy?editors=1010) |
| 33 | daffytseng | [Codepen](https://codepen.io/Daffy-Tseng/pen/EaYEVwq) |
| 34 | 五五(evelyn_hey2024) | [Codepen](https://codepen.io/EvelynCH/pen/OPLvNKb) |
| 35 | mu mu | [Codepen](https://codepen.io/ishuki916/pen/xbKjKPj?editors=1111) |
| 36 | Rylee | [Codepen](https://codepen.io/ryleezheng/pen/EaYLvbK) |
| 37 | JanllyGuo | [Codepen](https://codepen.io/kedugaw/pen/xbKYaOq) |
| 38 | hsin yu |   [Codepen](https://codepen.io/tina2793778/pen/NPKzXgz?editors=0010) | 
| 39 | wuyuli_21403 |   [Codepen](https://codepen.io/Job-Wilhelm/pen/raBKqGW) 
| 40 | will092317 |   [Codepen](https://codepen.io/xuazoblx-the-flexboxer/pen/RNbMVjX) /
| 41 | Arsian Kuo |   [Codepen](https://codepen.io/Arsian-Kuo/pen/wBwjxEq)
| 42 | chun0075 |   [Codepen](https://codepen.io/Lin-Angela/pen/emOPNap)
| 43 | 0111 |   [Codepen](https://codepen.io/0111mina/pen/LEPqvgd?editors=0011)
| 44 | Cami | [Codepen](https://codepen.io/irisLife/pen/EaxgroP) |
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|   |  |   [Codepen](作業網址放這邊) | 
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