104 lines
2.5 KiB
Markdown
104 lines
2.5 KiB
Markdown
---
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id: cf1111c1c12feddfaeb2bdef
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challengeType: 1
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videoUrl: 'https://scrimba.com/c/cm83yu6'
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forumTopicId: 18187
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localeTitle: 生成某个范围内的随机整数
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---
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## Description
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<section id='description'>
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我们之前生成的随机数是在0到某个数之间，现在我们要生成的随机数是在两个指定的数之间。
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我们需要定义一个最小值和一个最大值。
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下面是我们将要使用的方法，仔细看看并尝试理解这行代码到底在干嘛：
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<code>Math.floor(Math.random() * (max - min + 1)) + min</code>
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</section>
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## Instructions
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<section id='instructions'>
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创建一个叫<code>randomRange</code>的函数，参数为 myMin 和 myMax，返回一个在<code>myMin</code>（包括 myMin）和<code>myMax</code>（包括 myMax）之间的随机数。
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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>randomRange</code>返回的随机数应该大于或等于<code>myMin</code>。
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testString: assert(calcMin === 5);
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- text: <code>randomRange</code>返回的随机数应该小于或等于<code>myMax</code>。
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testString: assert(calcMax === 15);
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- text: <code>randomRange</code>应该返回一个随机整数, 而不是小数。
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testString: assert(randomRange(0,1) % 1 === 0 );
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- text: <code>randomRange</code>应该使用<code>myMax</code>和<code>myMin</code>, 并且返回两者之间的随机数。
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testString: assert((function(){if(code.match(/myMax/g).length > 1 && code.match(/myMin/g).length > 2 && code.match(/Math.floor/g) && code.match(/Math.random/g)){return true;}else{return false;}})());
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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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// Example
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function ourRandomRange(ourMin, ourMax) {
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return Math.floor(Math.random() * (ourMax - ourMin + 1)) + ourMin;
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}
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ourRandomRange(1, 9);
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// Only change code below this line.
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function randomRange(myMin, myMax) {
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return 0; // Change this line
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}
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// Change these values to test your function
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var myRandom = randomRange(5, 15);
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```
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</div>
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### After Test
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<div id='js-teardown'>
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```js
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var calcMin = 100;
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var calcMax = -100;
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for(var i = 0; i < 100; i++) {
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var result = randomRange(5,15);
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calcMin = Math.min(calcMin, result);
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calcMax = Math.max(calcMax, result);
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}
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(function(){
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if(typeof myRandom === 'number') {
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return "myRandom = " + myRandom;
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} else {
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return "myRandom undefined";
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}
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})()
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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 randomRange(myMin, myMax) {
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return Math.floor(Math.random() * (myMax - myMin + 1)) + myMin;
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}
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```
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</section>
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