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PHP学习札记(一)

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Jun 13, 2016 am 10:51 AM

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PHP学习笔记(一)

PHP的脚本以结束。在支持简写的服务器上，可以使用 ?>来开始和结束脚本块。为了兼容性，尽量使用标准形式。PHP通常会包含HTML标签，就像HTML文件，以及一些PHP脚本代码。下面是一段简单的PHP代码，

<html>   <?php echo "Hello World!"?></html>

有两种通过PHP来输出文本的基础指令，echo和print.

PHP中所有变量都是以$符号开始的。

设置变量的正确方法是：

$var_name = value;

PHP是一门松散类型的语言，在PHP中，不需要在设置变量之前声明该变量。

根据变量被设置的方式，PHP会自动地把变量转换为正确的数据类型。

在PHP中，变量会在使用时被自动声明。

在PHP中，只有一个字符串运算符。

并置运算符(.)用于把两个字符串连接起来。

如：

$txt1="Hello World";

$txt2="nihao";

echo $txt1 . " " . $txt2;

以上代码输出

Hello World nihao

strpos() 函数用于在字符串内检索一段字符串或一个字符。

如果在字符串中找到匹配，该函数会返回第一个匹配的位置。如果未找到匹配，则返回 FALSE。

如：

<?phpecho strpos("Hello world!","world");?>

返回的是6.（从0开始）

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