# 🗞 7/30 (五) － 變數章節總複習
###### tags: `JavaScript 必修篇 - 前端修練全攻略`
本日為變數章節：變數與資料型別 ～ 變數：布林、undefined、null 章節的總複習！
## 問題
### 題目一
請問以下變數的值、型別分別為何？
>回覆格式：a = 值、型別

let a = 1 + "我好棒";
let b = 1 * "我好棒";
let c = 2 > 1;
let d = 1 < 2;
let e;

### 題目二
請利用賦值運算子計算冰箱布丁剩餘數量：
>情境題 布丁剩多少？
>冰箱裡原有 15 顆布丁
>被妹妹拿走了 3 顆
>被姊姊拿走了 5 顆
>媽媽又冰了 10 顆
>弟弟拿走了 2 顆

//請透過此變數進行運算
let puddingNum = 15;



console.log(`布丁還有${puddingNum}顆`)

### 題目三
小美去飲料店買了很多飲料，但她數學不好，請利用以下步驟幫小美算出購買總額：

> 1. 1 杯紅茶 30 元
> 2. 小美買了 2 杯
> 3. 她將紅茶數量 * 紅茶價格，算出 60 元
> 4. 1 杯綠茶 25 元
> 5. 小美買了 4 杯
> 6. 她將綠茶數量 * 綠茶價格，算出 ?? 元
> 7. 1 杯奶茶 50元
> 8. 小美買了 6 杯
> 9. 她將奶茶數量 * 奶茶價格，算出 ?? 元
>

//帳單從零開始計算
let bill = 0 ;
const blackTeaPrice = 30;
let blackTeaNum = 2;
bill += blackTeaPrice*blackTeaNum;
//請接續步驟指引4，協助小美算出帳單金額





console.log(`小美總共花了${bill}元`)

### 題目四
請協助以下字串與數字轉型、過濾空白：

let number = "123";//將 number 轉型為數字
let string = 123;//將 string 轉型為字串
let myEmail ="  [e-mail]";//請將 myEmail 的空白過濾掉

## 回報流程
Fork 一份此[範例](https://codepen.io/jmkhsutp/pen/BaRYzBP?editors=0010)，並將答案寫在 CodePen 複製 CodePen 連結貼至下方作業投稿區中回報就算完成了喔!

## 作業投稿區(學員自行投稿)
1. [範例投稿](https://codepen.io/jmkhsutp/pen/GRmQqpx?editors=0011)（可點此連結觀看解答）
2. [Shelly](https://codepen.io/shellyhwung/pen/XWREvMM)
3. [JarvisYu](https://codepen.io/jarvis1993/pen/eYWrJYJ)
4. [phoebe](https://codepen.io/phoebe4561/pen/rNmvxaL?editors=0012)
5. [予予](https://codepen.io/kiqzcraa/pen/Vwbxvoy)
6. [allen0524](https://codepen.io/allen0524/pen/KKmRVgw)
7. [肉鬆](https://codepen.io/klrkicog/pen/WNjJrxV?editors=0011)
8. [群嘉](https://codepen.io/efzdamnp-the-lessful/pen/ZEKoQJB?editors=0011)
9. [Bucky](https://codepen.io/bucky-3414/pen/bGWMERX?editors=0012)
10. [LMY](https://codepen.io/l_umei/pen/LYymGRe)
11. [Fleur](https://codepen.io/swwlee/pen/yLbpoZE)
12. [Vic](https://codepen.io/hsuan333/pen/ZEKoQvL)
13. [teddy wu](https://codepen.io/hongwei0522/pen/poPVgej?editors=0011)
14. [Jack](https://codepen.io/yxzzktmb/pen/qBmYboo?editors=1012)
15. [Yunei](https://codepen.io/Yunei/pen/XWRqXgM)
16. [詠銓](https://codepen.io/GGfish26/pen/rNmvxdm?editors=0012)
17. [佳鈴](https://codepen.io/zpyfpsxa/pen/BaRxjJX?editors=0011)
18. [Izumi 泉](https://codepen.io/izumi-dev/pen/poPVgQN?editors=0011)
19. [陳sam](https://codepen.io/euldpliv/pen/RwVyrvO?editors=1011)
20. [Yi Chieh](https://codepen.io/Yi-Chieh/pen/NWjMNKr?editors=1011)
21. [curry](https://codepen.io/Ted19851223/pen/JjNvXdm?editors=1012)
22. [kk](https://codepen.io/potatokaka/pen/xxdjZzY?editors=0011)
23. [aha](https://codepen.io/aha36222/pen/GRmdZpR)
24. [Nick](https://codepen.io/nick-lin/pen/VwbxavN)
25. [Sandy](https://codepen.io/Sandy_L/pen/WNjJwxR?editors=0011)
26. [YC Lu](https://codepen.io/YCLu/pen/YzVLwgB)
27. [小韭菜](https://codepen.io/jhang-jhe-wei/pen/GRmdZOo)
28. [Chiang](https://codepen.io/ChiangJ/pen/WNjJwOj?editors=0011)
29. [Bear](https://codepen.io/adaibear/pen/MWmGyqX)
30. [番茄](https://codepen.io/Tomato451321-W/pen/YzVLqJy?editors=0011)
31. [阿丁兒](https://codepen.io/dingpachan/pen/oNWdxKX?editors=0010)
32. [Betty](https://codepen.io/gtut3252300/pen/zYwjBrg?editors=0011)
33. [andersonshen](https://codepen.io/luxyenni-the-bold/pen/qBmYZzB)
34. [timothy80617](https://codepen.io/timothy_hippo/pen/dyWeMqy?editors=0011)
35. [Rain](https://codepen.io/billpop741/pen/dyWeMxY)
36. [Yue](https://codepen.io/Nick-Yo/pen/gOWzMaR?editors=0011)
37. [wendy](https://codepen.io/siaochanwu/pen/BaRxLyv?editors=0011)
38. [shehome](https://codepen.io/ks0dcongra/pen/jOmxMKW?editors=0012)
39. [Jane Lin](https://codepen.io/as60160/pen/xxdjEaY)
40. [Wei](https://codepen.io/tartle120/pen/RwVyred)
41. [AndyTsai](https://codepen.io/AndyTsai/pen/jOmxMJM)
42. [Willy](https://codepen.io/cswilly901508/pen/XWRqjOz)
43. [Allen Lin](https://codepen.io/lcf7891/pen/eYWrZLP?editors=0012)
44. [Rain Liao](https://codepen.io/billpop741/pen/dyWeMxY)
45. [Howard](https://codepen.io/yawdnhbm/pen/NWjMbYg?editors=0011)
46. [Eva](https://codepen.io/hiYifang/pen/yLbjVxj?editors=0012)
47. [Shay](https://codepen.io/fromzeroo/pen/VwbxPLa?editors=0011)
48. [Bobo.Lin](https://codepen.io/boboloiono/pen/BaRxpJx?editors=0011)
49. [琪臻](https://codepen.io/ddnbmhxw/pen/yLbjgLR?editors=0111)
50. [wind](https://codepen.io/wind7y/pen/yLbjMja)
51. [Joe Kuo](https://codepen.io/alertislow/pen/xxdjdbJ?editors=0011)
52. [Arista](https://codepen.io/arista-hsieh/pen/QWvrvEd)
53. [SolA](https://codepen.io/ma_nyeo/pen/XWRqpGX?editors=0011)
54. [中年大叔](https://codepen.io/adens123/pen/OJmZgyj?editors=0011)
55. [kun.yin](https://codepen.io/arieslerry/pen/KKmRqpB)
56. [Rogan](https://codepen.io/kigwnlyg/pen/eYdjqEy)
57. [LALA](https://codepen.io/bobee/pen/GRmdvoX?editors=0011)
58. [Mobius](https://codepen.io/dopamine908/pen/abWGyYL)
59. [皮皮](https://codepen.io/super-shrimp/pen/wvdjrwK?editors=0010)
60. [weiwei](https://codepen.io/mihtcmff-the-typescripter/pen/qBmYPeW?editors=0012)
61. [Aga](https://codepen.io/jameshappy/pen/mdmLBaP?editors=0011)
62. [乃萱](https://codepen.io/nainaikuo/pen/mdmLqBM?editors=0011)
63. [chaci3](https://codepen.io/chaci33/pen/XWRqzdw?editors=0011)
64. [AmberCYT](https://codepen.io/amberTing/pen/PomeOeQ?editors=1011)
65. [Hedy](https://codepen.io/babogooyache/pen/BaRxWXN)
66. [Margo](https://codepen.io/MargoMin/pen/poPVdvZ?editors=0011)
67. [草皮](https://codepen.io/twgrass/pen/qBmYpjV?editors=0012)
68. [RuoAn](https://codepen.io/LiauRuoAn/pen/dyWeJYZ?editors=0012)
69. [Liam Chiu](https://codepen.io/LiamChiu/pen/GRmdQKV?editors=0011)
70. [洋蔥](https://codepen.io/mikeyam/pen/ZEKoazm?editors=0012)
71. [Nat](https://codepen.io/dxnqcnen/pen/ZEKoxrd)
72. [yojanni](https://codepen.io/unayo/pen/dyWemOM?editors=0010)
73. [肉魚](https://codepen.io/zoechen13/pen/zYwjWax?editors=0010)
74. [Mimino](https://codepen.io/mimino/pen/ZEKoovp?editors=0012)
75. [Fred](https://codepen.io/fred8196/pen/XWRqyWO?editors=1011)
76. [axlrock1021](https://codepen.io/andy1021/pen/YzZdYvO)
77. [Ulysses](https://codepen.io/dullshen/pen/LYymMMm?editors=0011)
78. [Avery](https://codepen.io/averyhsutw/pen/WNjJPNw)
79. [Wilson Han](https://codepen.io/wi0821/pen/VwbxgWO?editors=0011)
80. [ans9323052](https://codepen.io/ans9323052/pen/PomeVeN?editors=0011)
81. [weiliang](https://codepen.io/k7741118/pen/gOWzqBr)
82. [周周](https://codepen.io/jhoujhou-the-decoder/pen/rNmvgPZ?editors=0012)
83. [DoraYu](https://codepen.io/dora-yu/pen/MWmGdxG?editors=0011)
84. [Shiny](https://codepen.io/shinychen/pen/oNWyNBj)
85. [kimn](https://codepen.io/kimn/pen/BaRxxyG?editors=0011)
86. [colinhyun](https://codepen.io/colinhyun/pen/zYwarxr?editors=0011)
87. [LOMO](https://codepen.io/lockinglomo/pen/jOmKmmV)
88. [Shoppingq](https://codepen.io/shoppingq/pen/JjNZLzG)
89. [YinChenCheng](https://codepen.io/yinchengchen/pen/yLbEEPX?editors=0011)
90. [YuSung](https://codepen.io/kevin-hsu-the-encoder/pen/yLbEjEN?editors=0011)
91. [Eva](https://codepen.io/eva-1996/pen/xxdzarg?editors=0011)
92. [PeggyTsai](https://codepen.io/pei-chi-tsai/pen/mdmKaEp?editors=0011)
93. [阿Kai](https://codepen.io/kaihuang3013/pen/ZEKxPxz)
94. [Winnie](https://codepen.io/izobuwpl-the-vuer/pen/vYmrqBY?editors=0011)
95. [陳茄](https://codepen.io/TomatoIN/pen/gOWKVPv?editors=0010)
96. [Susan](https://codepen.io/susanbnak/pen/rNmKJaw)
97. [Jie](https://codepen.io/qgqonost-the-flexboxer/pen/PomBozG?editors=0011)
98. [柴貓](https://codepen.io/shibacat/pen/XWRBJbW)
99. [Lainie](https://codepen.io/Lainie88/pen/OJmwPbE?editors=1111)
100. [翁偉凌](https://codepen.io/wengweiling/pen/BaRPLGM)
101. [Judy Wei](https://codepen.io/Judy0718/pen/VwbBbKG?editors=0000)
102. [阿Kai](https://codepen.io/kaihuang3013/pen/bGWjKye)
103. [kevin huang](https://codepen.io/h2m730131/pen/abWaobJ)
104. [Joy Cheng](https://codepen.io/joycheng5432/pen/ZEKMEWr?editors=0011)
105. [poko](https://codepen.io/mingxuan-hsu/pen/JjNBJMg?editors=0012)
106. [Jung](https://codepen.io/ROUJUNG/pen/qBmMZeJ?editors=0012)
107. [Allensph](https://codepen.io/allensph/pen/PomdJWX)
108. [黑川](https://codepen.io/kurokawa/pen/oNWPMeO)
109. [Tim](https://codepen.io/jake1155/pen/xxdaoda)
110. [黛拉](https://codepen.io/YuYu_29/pen/YzVJxdZ?editors=0010)
111. [Sean Chang](https://codepen.io/seanchang7/pen/gOWBzdx?editors=0010)
112. [薰Shin](https://codepen.io/chiaoshin/pen/zYwmJBe)
113. [威利](https://codepen.io/wchu/pen/MWmzpvB)
114. [Kimberly](https://codepen.io/KIMBERLY_Yen/pen/mdmQXeM)
115. [誌](https://codepen.io/qoo9986360/pen/eYWQMpB?editors=0011)
116. [ABow_Chen](https://codepen.io/fred39392001/pen/oNWQQRm)
117. [Yiren](https://codepen.io/Yiren_Liou/pen/KKmEBZL)
118. [Churng](https://codepen.io/churng/pen/rNmbgpv?editors=0012)
119. [Amber_Lin](https://codepen.io/autum55853/pen/rNmgaGM?editors=0012)
120. [janice](https://codepen.io/janice880624/pen/zYwVGmj)
121. [claire](https://codepen.io/yi-wen-chen/pen/mdwbedg)
122. [Anki](https://codepen.io/contraryAK/pen/jOwEOWO?editors=0011)
123. [Peter](https://codepen.io/peter_hung/pen/MWoWMvb)
124. [安迪](https://codepen.io/andyang1030/pen/MWoYJNv?editors=0012)
125. [0214melody](https://codepen.io/Eileen-Ching/pen/gORazzV?editors=0010)
126. [傑瑞](https://codepen.io/auatwood909815/pen/yLXaJGq?editors=0012)
127. [莎賓娜](https://codepen.io/a120220ms25/pen/ExXgBJM?editors=0011)
128. [LucieW](https://codepen.io/Lucie_W/pen/NWgbVQW)
129. [Gill](https://codepen.io/Gill-Chin/pen/abwwpLm)
130. [WA](https://codepen.io/ldddl/pen/JjJrPQQ)
131. [Dana](https://codepen.io/asdana0220/pen/ExXByOW?editors=0012)
132. [歐玉嵐](https://codepen.io/oulan1221/pen/RwZbXYY)
133. [Mirmo](https://codepen.io/MirmoChamg/full/MWvwbRJ)
134. [betty Chen](https://codepen.io/Ying-Tzu/pen/porONgG?editors=0010)
135. [Sunny](https://codepen.io/Sunny0509/pen/VwzOyoz?editors=0010)
136. [Tina Yen](https://codepen.io/tlorfrnl-the-typescripter/pen/qBPWdPZ?editors=0011)
137. [庭瑋](https://codepen.io/wei_wu/pen/BawYJGW?editors=0011)
138. [鑫](https://codepen.io/huvup/pen/vYewYgm?editors=0011)
139. [Min](https://codepen.io/minnn7716/pen/GROxzpQ)
140. [Alice](https://codepen.io/Charlotte0805/pen/VwrdrWd?editors=0010)
141. [沈依蓉](https://codepen.io/lily-oa/pen/jOaJLvQ?editors=0010)
142. [Peihan Wang](https://codepen.io/PeihanWang/pen/qBpxwXp?editors=0011)
143. [Amberhh](https://codepen.io/Amberhh/pen/dyJmVab?editors=0011)
144. [GaryYang](https://codepen.io/fong-yuyang/pen/MWrqOqE?editors=1111)
145. [int Huang](https://codepen.io/intHuang/pen/oNpmNEw?editors=0011)
146. [Cindy Huang](https://codepen.io/cindyhuang888/pen/mdXegLz?editors=0011)
147. [Kevin Jiang](https://codepen.io/xlqjezvc-the-encoder/pen/poayqXo?editors=1111)
148. [JackC](https://codepen.io/key0329/pen/WNMRpQG?editors=0011)
149. [shio](https://codepen.io/shioyen/pen/jOZLMOJ?editors=0011)
150. [sophielam](https://codepen.io/sophiee2727/pen/NWyLQVQ?editors=0011)
151. [0808jessie](https://codepen.io/0808jessie/pen/PoRqjNg?editors=0012)
152. [YI](https://codepen.io/YI0305/pen/OJvyzaW?editors=0012)
153. [Cliff](https://codepen.io/Cliff_hex/pen/MWVjqWM?editors=0011)
154. [qoq77416416](https://codepen.io/qoq77416416/pen/BarZbYe?editors=0011)
155. [CookieSSS](https://codepen.io/sqhjikpa-the-selector/pen/OJvzVQN?editors=0011)
156. [Winnie](https://codepen.io/TzuHsuanWu/pen/GRxQPLX?editors=0010)
157. [Kimi](https://codepen.io/kimihu91/pen/zYWJGqQ?editors=0012)
158. [Cary](https://codepen.io/yi-chien-hsieh/pen/ZExVWGJ?editors=0012)
159. [RainJ](https://codepen.io/RainJCode/pen/poVbNpm?editors=0011)
160. [amy](https://codepen.io/amy-chieng/pen/NWMrEJx)
161. [Alex](https://codepen.io/datsxzqg-the-selector/pen/JjvyopX?editors=0011)
162. [piha](https://codepen.io/pihahaha/pen/PoeJLrP)
163. [Anna](https://codepen.io/rouchen/pen/YzLrMvq?editors=1012)
164. [SASIMI](https://codepen.io/sashimi1327/pen/zYjQGmJ)
165. [Eden](https://codepen.io/Eden-C/pen/OJEOXRb)
166. [vactiger](https://codepen.io/vactiger/pen/wvxxZEr)
167. [Yunifer](https://codepen.io/yunifer1227022/pen/abjxxwz)
168. [chih](https://codepen.io/ftbvujte-the-styleful/pen/VwGWwbe?editors=0011)
169. [Benson](https://codepen.io/rxttgpsr-the-reactor/pen/abaKGoZ)
170. [Wujiejie](https://codepen.io/kewdjbwp-the-typescripter/pen/MWPOyGr?editors=0011)
171. [淡水陳奕迅](https://codepen.io/josh1989213/pen/KKraKLY)
172. [Shin](https://codepen.io/ShinHT/pen/gOqRYqK)
173. [KiKi](https://codepen.io/ki-ki-the-builder/pen/oNmmqOb)
174. [HaoJing](https://codepen.io/hjxu/pen/OJqPJBv?editors=0011)
175. [GALU](https://codepen.io/regalue/pen/KKLOWBQ?editors=0011)
176. [Sophie](https://codepen.io/etffexym-the-sasster/pen/MWMgKmE)
177. [sowu](https://codepen.io/pelovndv-the-bold/pen/QWXjbYp)
178. [ABEI](https://codepen.io/uwmrsusb-the-solid/pen/vYqLLaW)
179. [Ralph](https://codepen.io/qqorzi/pen/mdZEeBY?editors=0010)
180. [柚子](https://codepen.io/yoogi0911/pen/VwoeYyV?editors=0112)
181. [William](https://codepen.io/lsaimqxa-the-vuer/pen/qEEYKyj?editors=0012)
182. [AIA](https://codepen.io/Acadia/pen/empNQEO?editors=0011)