103 lines
2.5 KiB
Markdown
103 lines
2.5 KiB
Markdown
---
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id: 587d7b8d367417b2b2512b5b
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title: Learn About Functional Programming
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challengeType: 1
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forumTopicId: 301233
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localeTitle: Узнайте о функциональном программировании
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---
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## Description
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<section id='description'>
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Functional programming is a style of programming where solutions are simple, isolated functions, without any side effects outside of the function scope.
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<code>INPUT -> PROCESS -> OUTPUT</code>
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Functional programming is about:
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1) Isolated functions - there is no dependence on the state of the program, which includes global variables that are subject to change
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2) Pure functions - the same input always gives the same output
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3) Functions with limited side effects - any changes, or mutations, to the state of the program outside the function are carefully controlled
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</section>
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## Instructions
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<section id='instructions'>
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The members of freeCodeCamp happen to love tea.
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In the code editor, the <code>prepareTea</code> and <code>getTea</code> functions are already defined for you. Call the <code>getTea</code> function to get 40 cups of tea for the team, and store them in the <code>tea4TeamFCC</code> variable.
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: The <code>tea4TeamFCC</code> variable should hold 40 cups of tea for the team.
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testString: assert(tea4TeamFCC.length === 40);
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- text: The <code>tea4TeamFCC</code> variable should hold cups of green tea.
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testString: assert(tea4TeamFCC[0] === 'greenTea');
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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/**
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* A long process to prepare tea.
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* @return {string} A cup of tea.
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**/
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const prepareTea = () => 'greenTea';
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/**
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* Get given number of cups of tea.
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* @param {number} numOfCups Number of required cups of tea.
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* @return {Array<string>} Given amount of tea cups.
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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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// Add your code below this line
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const tea4TeamFCC = null; // :(
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// Add your code above this line
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console.log(tea4TeamFCC);
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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// solution required
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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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</section>
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