php笔记

来源：互联网发布：sim800c 源码编辑：程序博客网时间：2024/06/10 12:09

<?php
$a = 44444;
$b = "qqqqqqqqqq$a";
echo $b . " ";

$c = 'qqqqqqqqqq$a';
echo $c;
echo " ";
echo strlen ( $c );
echo " ";
echo strlen ( $b );
echo " ";

$c = "q$a";
echo strrpos ( $c, '4' );
echo " ";

//函数定义 function 函数名(无数据类型形式参数){ return 返回值; }
function rightN($a, $n) {
//$substr = substr ( $str, strlen ( $str ) - $n );
$substr = substr ( $a, - $n );
return $substr;
}
$d = "abcdefg";
$n = 5;
//函数调用函数名(实参)
echo rightN ( $d, $n );
echo " ";

$fileName = "php大师.class.php";
//右边开始往左边找strrpos
//点号的位置，就是等于左边字符数汉字占2字节
echo substr($fileName,0,strrpos($fileName,'.'));
echo " ";

$xx = 55;
echo $xx++; //56
echo " ";
echo --$xx; //55
echo " ";

$yy = 33;
$zz = 44;
echo $yy.$zz;
echo " ";

$yy = "33";$zz = "44";
echo $yy+$zz;echo " ";
?>

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