50 lines
940 B
Markdown
50 lines
940 B
Markdown
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---
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title: While Loop
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localeTitle: 而Loop
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---
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## 而Loop
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`while loop`是PHP中最简单的循环类型之一。它执行语句块，直到表达式求值为**TRUE** 。如果表达式的值在执行时发生变化，则循环运行直到表达式求值为**FALSE。While**循环的基本形式如下：
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```shell
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while (expr)
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statement
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```
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while循环中的语句可以包含在花括号中，也可以根据以下语法使用：
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```shell
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while (expr):
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statement
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...
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endwhile;
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```
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使用示例说明while循环的简单和替代语法：
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```php
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<?php
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/* using the simple form of while loop */
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$i = 1; /* initialisation part */
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while ($i <= 100 && $i!=5 )
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{
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echo $i++;
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}
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/*using the alternate synatx of while loop*/
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$i = 0;
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while ($i <= 10):
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echo $i++;
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endwhile;
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?>
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```
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#### 更多信息
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[while循环 - PHP文档](http://php.net/manual/en/control-structures.while.php)
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