75 lines
2.0 KiB
Markdown
75 lines
2.0 KiB
Markdown
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---
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id: a302f7aae1aa3152a5b413bc
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title: Factorialize a Number
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isRequired: true
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challengeType: 5
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---
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## Description
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<section id='description'>
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Return the factorial of the provided integer.
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If the integer is represented with the letter n, a factorial is the product of all positive integers less than or equal to n.
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Factorials are often represented with the shorthand notation <code>n!</code>
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For example: <code>5! = 1 * 2 * 3 * 4 * 5 = 120</code>
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Only integers greater than or equal to zero will be supplied to the function.
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Remember to use <a href="http://forum.freecodecamp.org/t/how-to-get-help-when-you-are-stuck/19514" target="_blank">Read-Search-Ask</a> if you get stuck. Write your own code.
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</section>
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## Instructions
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<section id='instructions'>
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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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- text: <code>factorialize(5)</code> should return a number.
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testString: 'assert(typeof factorialize(5) === "number", "<code>factorialize(5)</code> should return a number.");'
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- text: <code>factorialize(5)</code> should return 120.
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testString: 'assert(factorialize(5) === 120, "<code>factorialize(5)</code> should return 120.");'
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- text: <code>factorialize(10)</code> should return 3628800.
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testString: 'assert(factorialize(10) === 3628800, "<code>factorialize(10)</code> should return 3628800.");'
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- text: <code>factorialize(20)</code> should return 2432902008176640000.
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testString: 'assert(factorialize(20) === 2432902008176640000, "<code>factorialize(20)</code> should return 2432902008176640000.");'
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- text: <code>factorialize(0)</code> should return 1.
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testString: 'assert(factorialize(0) === 1, "<code>factorialize(0)</code> should return 1.");'
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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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function factorialize(num) {
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return num;
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}
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factorialize(5);
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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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function factorialize(num) {
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return num < 1 ? 1 : num * factorialize(num - 1);
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}
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factorialize(5);
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```
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</section>
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