82 lines
3.2 KiB
Markdown
82 lines
3.2 KiB
Markdown
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---
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id: 56533eb9ac21ba0edf2244d8
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title: Comparisons with the Logical And Operator
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challengeType: 1
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videoUrl: ''
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localeTitle: 与逻辑和运算符的比较
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---
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## Description
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<section id="description">有时你需要一次测试多个东西。当且仅当其左侧和右侧的<dfn>操作数</dfn>为<code>true</code>时， <dfn>逻辑和</dfn>运算符（ <code>&&</code> ）才返回true。如果将if语句嵌套在另一个语句中，则可以实现相同的效果： <blockquote> if（num> 5）{ <br> if（num <10）{ <br>返回“是”; <br> } <br> } <br>返回“否”; </blockquote>如果<code>num</code>大于<code>5</code>且小于<code>10</code>则仅返回“Yes”。相同的逻辑可以写成： <blockquote> if（num> 5 && num <10）{ <br>返回“是”; <br> } <br>返回“否”; </blockquote></section>
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## Instructions
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<section id="instructions">将两个if语句合并为一个语句，如果<code>val</code>小于或等于<code>50</code>且大于或等于<code>25</code> ，则返回<code>"Yes"</code> 。否则，将返回<code>"No"</code> 。 </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: 你应该使用一次<code>&&</code>运算符
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testString: 'assert(code.match(/&&/g).length === 1, "You should use the <code>&&</code> operator once");'
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- text: 你应该只有一个<code>if</code>语句
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testString: 'assert(code.match(/if/g).length === 1, "You should only have one <code>if</code> statement");'
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- text: <code>testLogicalAnd(0)</code>应返回“否”
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testString: 'assert(testLogicalAnd(0) === "No", "<code>testLogicalAnd(0)</code> should return "No"");'
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- text: <code>testLogicalAnd(24)</code>应返回“否”
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testString: 'assert(testLogicalAnd(24) === "No", "<code>testLogicalAnd(24)</code> should return "No"");'
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- text: <code>testLogicalAnd(25)</code>应返回“是”
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testString: 'assert(testLogicalAnd(25) === "Yes", "<code>testLogicalAnd(25)</code> should return "Yes"");'
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- text: <code>testLogicalAnd(30)</code>应该返回“是”
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testString: 'assert(testLogicalAnd(30) === "Yes", "<code>testLogicalAnd(30)</code> should return "Yes"");'
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- text: <code>testLogicalAnd(50)</code>应该返回“是”
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testString: 'assert(testLogicalAnd(50) === "Yes", "<code>testLogicalAnd(50)</code> should return "Yes"");'
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- text: <code>testLogicalAnd(51)</code>应返回“否”
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testString: 'assert(testLogicalAnd(51) === "No", "<code>testLogicalAnd(51)</code> should return "No"");'
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- text: <code>testLogicalAnd(75)</code>应返回“否”
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testString: 'assert(testLogicalAnd(75) === "No", "<code>testLogicalAnd(75)</code> should return "No"");'
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- text: <code>testLogicalAnd(80)</code>应返回“否”
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testString: 'assert(testLogicalAnd(80) === "No", "<code>testLogicalAnd(80)</code> should return "No"");'
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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 testLogicalAnd(val) {
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// Only change code below this line
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if (val) {
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if (val) {
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return "Yes";
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}
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}
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// Only change code above this line
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return "No";
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}
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// Change this value to test
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testLogicalAnd(10);
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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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```
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</section>
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