87 lines
1.9 KiB
Markdown
87 lines
1.9 KiB
Markdown
---
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id: 587d7b8d367417b2b2512b5b
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title: 學習函數式編程
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challengeType: 1
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forumTopicId: 301233
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dashedName: learn-about-functional-programming
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---
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# --description--
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函數式編程是一種方案簡單、功能獨立、對作用域外沒有任何副作用的編程範式：`INPUT -> PROCESS -> OUTPUT`。
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函數式編程：
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1）功能獨立——不依賴於程序的狀態（比如可能發生變化的全局變量）；
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2）純函數——同一個輸入永遠能得到同一個輸出；
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3）有限的副作用——可以嚴格地限制函數外部對狀態的更改。
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# --instructions--
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freeCodeCamp 的成員們愛喝茶。
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在代碼編輯器中，已經爲你定義好了`prepareTea`和`getTea`函數。 調用 `getTea` 函數爲團隊準備 40 杯茶，並將它們存儲在 `tea4TeamFCC` 變量裏。
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# --hints--
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`tea4TeamFCC` 變量裏應有 40 杯爲團隊準備的茶。
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```js
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assert(tea4TeamFCC.length === 40);
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```
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`tea4TeamFCC` 變量裏應有幾杯 greenTea（綠茶）。
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```js
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assert(tea4TeamFCC[0] === 'greenTea');
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```
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# --seed--
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## --seed-contents--
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```js
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// Function that returns a string representing a cup of green tea
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const prepareTea = () => 'greenTea';
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/*
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Given a function (representing the tea type) and number of cups needed, the
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following function returns an array of strings (each representing a cup of
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a specific type of tea).
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*/
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const getTea = (numOfCups) => {
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const teaCups = [];
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for(let cups = 1; cups <= numOfCups; cups += 1) {
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const teaCup = prepareTea();
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teaCups.push(teaCup);
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}
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return teaCups;
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};
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// Only change code below this line
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const tea4TeamFCC = null;
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// Only change code above this line
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```
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# --solutions--
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```js
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const prepareTea = () => 'greenTea';
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const getTea = (numOfCups) => {
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const teaCups = [];
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for(let cups = 1; cups <= numOfCups; cups += 1) {
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const teaCup = prepareTea();
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teaCups.push(teaCup);
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}
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return teaCups;
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};
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const tea4TeamFCC = getTea(40);
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```
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