1、基础语法
<?php>
//PHP代码
?>
2、PHP文件的默认扩展名为.php
<?php>
echo "hello world !"; //echo为内建的PHP函数,输出文本。
?>
3、变量
以$符号开头,后面为变量的名称:$ x
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4、两种基本的输出方法:echo 和 print语句
echo:能够输出一个以上的字符串
<?php $txt1="Learn PHP"; $txt2="W3School.com.cn"; $cars=array("Volvo","BMW","SAAB"); echo $txt1; echo "<br>"; echo "Study PHP at $txt2"; echo "My car is a {$cars[0]}"; ?>
print:只能输出一个字符串,并始终返回1
<?php $txt1="Learn PHP"; $txt2="W3School.com.cn"; $cars=array("Volvo","BMW","SAAB"); print $txt1; print "<br>"; print "Study PHP at $txt2"; print "My car is a {$cars[0]}"; ?>
5、返回字符串的长度 PHP strlen()函数
<?php echo strlen("Hello world!"); ?>6、检索字符串内指定的字符 PHP strpos() 函数,找到匹配则返回位置,若没有则返回false
<?php echo strpos("Hello world!","world"); ?>7、函数
使用function定义函数
function functionName() { 被执行的代码; }
8、数组
<?php $cars=array("Volvo","BMW","SAAB"); echo "I like " . $cars[0] . ", " . $cars[1] . " and " . $cars[2] . "."; ?>获得数组的长度:
<?php $cars=array("Volvo","BMW","SAAB"); echo count($cars); ?>遍历索引数组:
<?php $cars=array("Volvo","BMW","SAAB"); $arrlength=count($cars); for($x=0;$x<$arrlength;$x++) { echo $cars[$x]; echo "<br>"; } ?>关联数组:
$age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");遍历关联数组:
<?php $age=array("Bill"=>"35","Steve"=>"37","Peter"=>"43"); foreach($age as $x=>$x_value) { echo "Key=" . $x . ", Value=" . $x_value; echo "<br>"; } ?>9、数组排序
- sort() - 以升序对数组排序
-
<?php $cars=array("Volvo","BMW","SAAB"); sort($cars); ?>
- rsort() - 以降序对数组排序
-
<?php $cars=array("Volvo","BMW","SAAB"); rsort($cars); ?>
- asort() - 根据值,以升序对关联数组进行排序
-
<?php $age=array("Bill"=>"35","Steve"=>"37","Peter"=>"43"); asort($age); ?>
- ksort() - 根据键,以升序对关联数组进行排序
-
<?php $age=array("Bill"=>"35","Steve"=>"37","Peter"=>"43"); ksort($age); ?>
- arsort() - 根据值,以降序对关联数组进行排序
-
<?php $age=array("Bill"=>"35","Steve"=>"37","Peter"=>"43"); arsort($age); ?>
- krsort() - 根据键,以降序对关联数组进行排序
-
<?php $age=array("Bill"=>"35","Steve"=>"37","Peter"=>"43"); krsort($age); ?>
10、$_REQUEST:用于收集HTML表单提交的数据
<html> <body> <form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>"> Name: <input type="text" name="fname"> <input type="submit"> </form> <?php $name = $_REQUEST['fname']; echo $name; ?> </body> </html>11、$_POST:用于收集提交 method="post" 的 HTML 表单后的表单数据
<html> <body> <form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>"> Name: <input type="text" name="fname"> <input type="submit"> </form> <?php $name = $_POST['fname']; echo $name; ?> </body> </html>12、$_GET:于收集提交 HTML 表单 (method="get") 之后的表单数据
<html> <body> <a href="test_get.php?subject=PHP&web=W3school.com.cn">测试 $GET</a> </body> </html>