63 lines
2.3 KiB
Markdown
63 lines
2.3 KiB
Markdown
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---
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id: 599a789b454f2bbd91a3ff4d
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title: Practice comparing different values
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challengeType: 1
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videoUrl: ''
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localeTitle: 练习比较不同的值
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---
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## Description
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<section id="description">在最后两个挑战中，我们学习了等于运算符（ <code>==</code> ）和严格相等运算符（ <code>===</code> ）。让我们快速回顾一下这些运算符的实践。如果要比较的值不是同一类型，则相等运算符将执行类型转换，然后计算值。但是，严格相等运算符将按原样比较数据类型和值，而不将一种类型转换为另一种类型。 <strong>例子</strong> <blockquote> 3 =='3'//返回true，因为JavaScript执行从字符串到数字的类型转换<br> 3 ==='3'//返回false，因为类型不同并且未执行类型转换</blockquote> <strong>注意</strong> <br>在JavaScript中，您可以使用<code>typeof</code>运算符确定变量的类型或值，如下所示： <blockquote> typeof 3 //返回'number' <br> typeof'3'//返回'string' </blockquote></section>
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## Instructions
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<section id="instructions">编辑器中的<code>compareEquality</code>函数使用<code>equality operator</code>比较两个值。修改函数，使其仅在值严格相等时返回“Equal”。 </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>compareEquality(10, "10")</code>应返回“Not Equal”'
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testString: 'assert(compareEquality(10, "10") === "Not Equal", "<code>compareEquality(10, "10")</code> should return "Not Equal"");'
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- text: '<code>compareEquality("20", 20)</code>应该返回“Not Equal”'
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testString: 'assert(compareEquality("20", 20) === "Not Equal", "<code>compareEquality("20", 20)</code> should return "Not Equal"");'
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- text: 您应该使用<code>===</code>运算符
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testString: 'assert(code.match(/===/g), "You should use the <code>===</code> operator");'
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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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// Setup
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function compareEquality(a, b) {
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if (a == b) { // Change this line
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return "Equal";
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}
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return "Not Equal";
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}
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// Change this value to test
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compareEquality(10, "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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