73 lines
1.9 KiB
Markdown
73 lines
1.9 KiB
Markdown
---
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id: 587d7b7e367417b2b2512b22
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title: Use the parseInt Function with a Radix
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/c6K4Kh3'
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forumTopicId: 301182
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---
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## Description
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<section id='description'>
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The <code>parseInt()</code> function parses a string and returns an integer. It takes a second argument for the radix, which specifies the base of the number in the string. The radix can be an integer between 2 and 36.
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The function call looks like:
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<code>parseInt(string, radix);</code>
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And here's an example:
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<code>var a = parseInt("11", 2);</code>
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The radix variable says that "11" is in the binary system, or base 2. This example converts the string "11" to an integer 3.
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</section>
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## Instructions
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<section id='instructions'>
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Use <code>parseInt()</code> in the <code>convertToInteger</code> function so it converts a binary number to an integer and returns it.
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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: <code>convertToInteger</code> should use the <code>parseInt()</code> function
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testString: assert(/parseInt/g.test(code));
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- text: <code>convertToInteger("10011")</code> should return a number
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testString: assert(typeof(convertToInteger("10011")) === "number");
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- text: <code>convertToInteger("10011")</code> should return 19
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testString: assert(convertToInteger("10011") === 19);
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- text: <code>convertToInteger("111001")</code> should return 57
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testString: assert(convertToInteger("111001") === 57);
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- text: <code>convertToInteger("JamesBond")</code> should return NaN
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testString: assert.isNaN(convertToInteger("JamesBond"));
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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 convertToInteger(str) {
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}
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convertToInteger("10011");
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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 convertToInteger(str) {
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return parseInt(str, 2);
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}
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```
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</section>
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