---
# System prepended metadata

title: "\U0001F3C5 JS 任務 Day6 - if 流程判斷 II"
tags: [30 天軟體工程師體驗營｜2025]

---

---
tags: 30 天軟體工程師體驗營｜2025
---
> 建議觀看的影音章節：
> JS - 流程判斷 - if、else if、else
> JS - if 流程圖規劃流程
> JS - if 中階運用

# 🏅 JS 任務 Day6 - if 流程判斷 II

### 題目一：日幣計算機 (1:0.32)

``` =JavaScript
// input 輸入
TWDtoJPY(-1)
TWDtoJPY("hi~")
TWDtoJPY(2000)
TWDtoJPY(320)
// output 輸出
"...沒錢別來亂"
"當我看不懂字串？？"
"你換到的日幣有：6250"
"你換到的日幣有：1000"

```
### 題目二：匯率計算機
* 美金：1:29
* 港幣：1:3
* 英鎊：1:35
``` =JavaScript
// input 輸入
TWDtoAnother(100,"USD")
TWDtoAnother(100,"Sword Art Online")
TWDtoAnother(100,"HKD")
TWDtoAnother(100,"GBP")

// output 輸出
"2900"
"..."
"300"
"3500"
```

### 題目三：BMI 計算機
* [公式](https://depart.femh.org.tw/dietary/3OPD/BMI.htm)
``` =JavaScript
// input 輸入 
// BMI(身高,體重)

// output 輸出
"正常"
"重度肥胖"
"中度肥胖"
"輕度肥胖"
"過重"
"過輕"
```

## 進階題，不適合新手
### 字串切割+if
* 如果第一個數字是質數，請將第二、三個數字加總
* 如果第一個數字是偶數，請將第二、三個數字相減
* 如果第一個數字不是質數也不是偶數，請將第二、三個數字相乘
``` =JavaScript
// input 輸入
sum("13,20,10")
sum("10,2,3")
sum("9,5,7")
// output 輸出
30
-1
35
```

## 回報流程

1. 將答案貼在 Codepen 並複製 Codepen 連結貼至「回報區」回報
（也可以將答案直接貼至「回報區」）

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

## 回報區

| 報數 | Discord 名字 | CodePen／其他回饋                                                               |
|:----:|:------------:| ------------------------------------------------------------------------------- |
| 1 | 蛋白 | [蛋白的JS CodePen Day6](https://codepen.io/sjlu-0/pen/wBBjggB)|
|2|小趴|[Codepen](https://codepen.io/papa2415/pen/yLrWrjb)|
| 3 | 4chan | [Codepen](https://codepen.io/ijuolaqc-the-looper/pen/vEEjgGv)|
| 4 | dean  | [codepen](https://codepen.io/ch933114/pen/ByyxpVj?editors=0011)|
| 5 | ying | [Codepen](https://codepen.io/Lara-Lin/pen/vEEjxgL?editors=1111)|
| 6 | B | [Codepen](https://codepen.io/Babel777/pen/MYYGJMV)|
| 7 | 叮咚 | [Codepen](https://codepen.io/pinchieh-lin/pen/yyyjoOj?editors=1111)|
| 8 | RUDY | [Codepen](https://codepen.io/Rudy-crw/pen/WbbJEgJ?editors=0010)|
| 9 | Toung | [Codepen](https://codepen.io/Toung/pen/LEEmWrp)
| 10 | 馬德 | [Codepen](https://codepen.io/maywang/pen/xbbjgoM)
| 11 | Archang  | [CodePen](https://codepen.io/pxfnrvgk-the-styleful/pen/KwwRqoW)|
| 12 | pastor | [Codepen](https://codepen.io/peter_hung/pen/vEEjxqm)|
| 13 | 登登登 | [Codepen](https://codepen.io/Duncanin/pen/bNNMRbb) |
| 14 | Joseph_Kyuu| [Codepen](https://codepen.io/zrzfastd-the-reactor/pen/jEExLjQ) |
| 15 | Anna | [Codepen](https://codepen.io/Anna-Teng/pen/gbbzXYE?editors=1011)|
|16|Saika| [Codepen](https://codepen.io/saika4501/pen/GggdyNq?editors=0011)|
|17|ann.328| [Codepen](https://codepen.io/yqmegupa-the-styleful/pen/wBBjybb)|
|18|7Lun| [Day6-Codepen](https://codepen.io/mfyvqhsn-the-bold/pen/gbbeMjr)|
| 19 | 力文 | [CodePen](https://codepen.io/liwenchiou/pen/pvvVLNE?editors=0011)|
| 20 | CBK | [CodePen](https://codepen.io/BK-C-the-styleful/pen/Pwweayx)|
| 21 | WAWATA | [CodePen](https://codepen.io/wa-wa-GNOHC-WA-Wa/pen/WbbJKeN)|
| 22 | 清蒸蚊子(avytaurus) | [CodePen](https://codepen.io/jtmlthhe-the-bashful/pen/zxxjLxz)|
|  23  |    Jessie    |         [Jessie 的 Codepen](https://codepen.io/bakyfkso-the-looper/pen/azzGGPb)
|  24  |    BL    |         [Codepen](https://codepen.io/bonnieli1414/pen/myyLKQj?editors=0011)
| 25 | 牛奶 | [CodePen](https://codepen.io/0omilko0/pen/gbbzdrM?editors=0011)|
| 26 | Hugh | [CodePen](https://codepen.io/Hugh-Chen/pen/ZYYojNr?editors=0011)|
| 27 | mambo | [CodePen](https://codepen.io/chiang_mb/pen/raavZGo)|
|  28  | ArvinSu | [Codepen](https://codepen.io/Arvin-Su/pen/azzGaxb) |
|29|yang|[codepen](https://codepen.io/Yang-J/pen/emmrLoa?editors=0012)|
|30| mercury2508. |[Codepen](https://codepen.io/Mercury2508/pen/QwwrRwZ)|
| 31 | Cami | [Codepen](https://codepen.io/irisLife/pen/LEEmQGb)|
| 32 | wei_0982 | [Codepen](https://codepen.io/nico-lai/pen/KwwRZxx)|
| 33 | stone | [Codepen](https://codepen.io/bgrwlzoz-the-reactor/pen/bNNKbNM)|
|  34  | Ali | [Codepen](https://codepen.io/Alicia1117/pen/LEEmJjP) |
|  35  | Ali | [Codepen](https://codepen.io/HoshinoSyouta/pen/LEEmJBV?editors=0012) |
|  36  | Kath | [Codepen](https://codepen.io/JLin-the-lessful/pen/pvvKyYo) |
|  37  | 野鴿 | [Codepen](https://codepen.io/HoshinoSyouta/pen/LEEmJBV) |
|  38  | William Hsieh | [Codepen](https://codepen.io/lsaimqxa-the-vuer/pen/XJJYKqz?editors=0012) |
|  39  | nora_zizi | [Codepen](https://codepen.io/Nora-Ch/pen/raaKLQY?editors=1111) |
|  40  | jingle0900 | [Codepen](https://codepen.io/EvaLi0472/pen/bNNKMZY?editors=1010) |
| 41  | WEIWEI | [Codepen](https://codepen.io/weiwei93/pen/xbbWLPG) |
| 42  | Chuang | [Codepen](https://codepen.io/uidoytjq-the-solid/pen/zxxLYVp) |
| 43  | Leonard | [Codepen](https://codepen.io/hyyfjqra-the-sans/pen/azzjZww) 
|  44  | Apple Pie | [Codepen](https://codepen.io/ymevqzjf-the-builder/pen/zxxjNML?editors=0011) 進階題待補|
| 45  | ninii | [Codepen](https://codepen.io/niiniiii/pen/qEEyjZj?editors=1112) 
|46|蛋殼|[Codepen](https://codepen.io/weybrian/pen/JooBgoL)
|47|Rogan|[Codepen](https://codepen.io/RoganHsu/pen/MYYqKyp?editors=1111)
|  48  | Owen He | [Codepen](https://codepen.io/owen1120/pen/dPPKgNp?editors=0012) 
|  49  | 姜承 | [Codepen](https://codepen.io/Troy0718/pen/jOeaRoE?editors=1011) |
|  50  | Sonia | [Codepen](https://codepen.io/YUJOU/pen/raaqYGN?editors=0012) |
|  51  | oyll | [Codepen](https://codepen.io/dizzydog-rgb/pen/GggYQvo?editors=0011) |
|  52  | Ariel| [Codepen](https://codepen.io/ariel0510/pen/pvvxLeG?editors=0011) |
|53|JHT|[Codepen](https://codepen.io/juanht/pen/KwwJMoo?editors=0012)|
|54|ja4071|[Codepen](https://codepen.io/SHAO-L/pen/PwwgwaJ?editors=1112)|
|55| vima |[Codepen](https://codepen.io/chin7004/pen/QwwoBmv?editors=0011)|
|56| kelsonhouse |[Codepen](https://codepen.io/Kelson-House/pen/MYYRozO?editors=0012)|
|  57  | YuTing | [Codepen](https://codepen.io/venus50533/pen/gbbyjjO) |
|  58  | allen3290 | [Codepen](https://codepen.io/udadkudw-the-looper/pen/raabEYG?editors=1111) |
|  59  | duchi | [Codepen](https://codepen.io/sqaz0502/pen/MYYxGGR) |
|  60  | Mic | [Codepen](https://codepen.io/Mic-Pan/pen/qEdWZMB?editors=0011) |
|  61  | Yi-Kuei | [Codepen](https://codepen.io/Yi-Kuei-Chuang/pen/qEdWMjx?editors=1112) |
|  62  | Xiaocai_97765 | [Codepen](https://codepen.io/dupre55667788/pen/qEdBVzR?editors=0110)
|  63  | 610 | [Codepen](https://codepen.io/YI-LING-LIU/pen/PwqZBPv)
|  64  | taishan_90178 | [Codepen](https://codepen.io/candy99/pen/zxGEYmj?editors=0012)
|  65  | rinn | [Codepen](https://codepen.io/cqsioetr-the-bold/pen/MYwjWBy?editors=0011)
|  66  | kent_31665 | [Codepen](https://codepen.io/kentlee406/pen/emNKLOo)
|  67  | World | [Codepen](https://codepen.io/HexschoolVuePujols/pen/xbGabXx)
| 68 | haohaoliao | [Codepen](https://codepen.io/yuyuyuhaohao/pen/qEbdPYj)
<!-- 解答：
題目一：
function TWDtoJPY(twd) {
  if (typeof twd !== "number") {
    return "當我看不懂字串？？";
  }
  if (twd < 0) {
    return "...沒錢別來亂";
  }
  const jpy = Math.floor(twd / 0.32);
  return `你換到的日幣有：${jpy}`;
}

題目二：
function TWDtoAnother(twd, currency) {
  const rates = {
    USD: 29,
    HKD: 3,
    GBP: 35,
  };

  if (!rates[currency]) {
    return "...";
  }

  return (twd * rates[currency]).toString();
}

題目三：
function BMI(height, weight) {
  const h = height / 100;
  const bmi = weight / (h * h);

  if (bmi < 18.5) return "過輕";
  if (bmi < 24) return "正常";
  if (bmi < 27) return "過重";
  if (bmi < 30) return "輕度肥胖";
  if (bmi < 35) return "中度肥胖";
  return "重度肥胖";
}


進階題：
function isPrime(n) {
  if (n <= 1) return false;
  for (let i = 2; i <= Math.sqrt(n); i++) {
    if (n % i === 0) return false;
  }
  return true;
}

function sum(str) {
  const [a, b, c] = str.split(',').map(Number);
  if (isPrime(a)) return b + c;
  if (a % 2 === 0) return b - c;
  return b * c;
}

回報區
---


| 報數 | Discord 名字 |                               Codepen／其他回饋                               |
|:----:|:------------:|:-----------------------------------------------------------------------------:|

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