65 lines
2.6 KiB
Markdown
65 lines
2.6 KiB
Markdown
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---
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id: 56533eb9ac21ba0edf2244d0
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title: Comparison with the Equality Operator
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challengeType: 1
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videoUrl: ''
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localeTitle: 与平等算子的比较
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---
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## Description
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<section id="description">有很多<dfn>比较运算符</dfn>在JavaScript中。所有这些运算符都返回布尔值<code>true</code>或<code>false</code>值。最基本的运算符是等于运算符<code>==</code> 。等于运算符比较两个值，如果它们是等价的则返回<code>true</code>否则返回<code>false</code> 。请注意，相等性与赋值（ <code>=</code> ）不同，后者将运算符右侧的值分配给左侧的变量。 <blockquote> function equalityTest（myVal）{ <br> if（myVal == 10）{ <br>返回“平等”; <br> } <br>返回“不等于”; <br> } </blockquote>如果<code>myVal</code>等于<code>10</code> ，则等于运算符返回<code>true</code> ，因此大括号中的代码将执行，函数将返回<code>"Equal"</code> 。否则，该函数将返回<code>"Not Equal"</code> 。为了使JavaScript能够比较两种不同的<code>data types</code> （例如， <code>numbers</code>和<code>strings</code> ），它必须将一种类型转换为另一种类型。这被称为“类型强制”。但是，一旦它完成，它可以比较如下术语： <blockquote> 1 == 1 //是的<br> 1 == 2 //假<br> 1 =='1'//是的<br> “3”== 3 //是的</blockquote></section>
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## Instructions
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<section id="instructions">将<code>equality operator</code>添加到指示的行，以便当<code>val</code>等于<code>12</code>时，函数将返回“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>testEqual(10)</code>应该返回“Not Equal”
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testString: 'assert(testEqual(10) === "Not Equal", "<code>testEqual(10)</code> should return "Not Equal"");'
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- text: <code>testEqual(12)</code>应返回“Equal”
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testString: 'assert(testEqual(12) === "Equal", "<code>testEqual(12)</code> should return "Equal"");'
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- text: <code>testEqual("12")</code>应返回“Equal”
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testString: 'assert(testEqual("12") === "Equal", "<code>testEqual("12")</code> should return "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) && !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 testEqual(val) {
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if (val) { // 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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testEqual(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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