58 lines
1.4 KiB
Markdown
58 lines
1.4 KiB
Markdown
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---
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title: Introducing Else statements
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localeTitle: 介绍Else语句
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---
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## 介绍Else语句
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### 问题解释：
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· _将`if`语句组合到单个`if/else`语句中。_
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#### 提示1
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当第一个`if`语句返回`false` ，执行/评估下一段代码（如`return` ， `if`或`else`语句）。
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> _现在尝试解决问题_
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#### 提示2
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有时`if` （ `condition` ）语句可以用`else {code to execute instead}`语句`else {code to execute instead}` （实质上你告诉你的函数做_“y”，_如果它不能做_“x”_而不是多次指定_“x”_ ）。
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> _现在尝试解决问题_
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## 扰流板警报！
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**提前解决！**
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## 基本代码解决方案
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```javascript
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function testElse(val) {
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var result = "";
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// Only change code below this line
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if (val > 5) {
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result = "Bigger than 5";
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}
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else {
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result = "5 or smaller";
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}
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// Only change code above this line
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return result;
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}
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// Change this value to test
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testElse(4);
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```
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· [在repl.it上运行代码](https://repl.it/@AdrianSkar/Introducing-else-statements)
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### 代码说明
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功能首先评估`if`条件`val > 5`的计算结果为`true` 。如果没有，则执行下一个语句（ `else { return "5 or smaller";})` 。
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### 资源
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* [“if ... else” - _MDN JavaScript参考_](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/if…else)
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