92 lines
1.5 KiB
Markdown
92 lines
1.5 KiB
Markdown
---
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title: Switch statement
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localeTitle: 切换声明
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---
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# 开关
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`Switch`是一个选择语句，它将选择一个switch语句并从候选列表中执行它。 Switch由`case`和可选的`default` 。可以使用`break`或`return`来停止执行。
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## 句法
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```
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switch(x)
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{
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case value1:
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//execute if x = value1
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break;
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case value2:
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//execute if x = value2
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break;
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...
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default:
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execute if x is different with cases above
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}
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```
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## 例
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```php
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<?php
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//initialize with a random integer within range
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$diceNumber = mt_rand(1, 6);
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//initialize
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$numText = "";
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//calling switch statement
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switch($diceNumber)
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{
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case 1:
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$numText = "One";
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break;
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case 2:
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$numText = "Two";
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break;
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case 3:
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case 4:
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// case 3 and 4 will go to this line
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$numText = "Three or Four";
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break;
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case 5:
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$numText = "Five";
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echo $numText;
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// break; //without specify break or return it will continue execute to next case.
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case 6:
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$numText = "Six";
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echo $numText;
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break;
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default:
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$numText = "unknown";
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}
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//display result
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echo 'Dice show number '.$numText.'.';
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?>
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```
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## 产量
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```
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if case is 1
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> Dice show number One.
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if case is 2
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> Dice show number Two.
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if case is 3
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> Dice show number Three or Four.
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if case is 4
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> Dice show number Three or Four.
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if case is 5
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> FiveSixDice show number Six.
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if case is 6
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> SixDice show number Six.
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if none of the above
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> Dice show number unknown.
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``` |