摘要：//1.确定字符串长度 //strlen函数和mb_strlen函数，后者需要开启mbstring扩展 $str = 'abcdef'; echo strlen($str); // 6 echo "<br/>"; $str = ' ab c
//1.确定字符串长度
//strlen函数和mb_strlen函数，后者需要开启mbstring扩展
$str = 'abcdef';
echo strlen($str); // 6
echo "<br/>";
$str = ' ab cd ';
echo mb_strlen($str); // 7
echo "<br/>";
//2.分割连接反转
//str_split函数、split函数、explode函数和implode函数
//
//
$str = "Hello Friend";
$arr1 = str_split($str);
print_r($arr1);
$arr2 = str_split($str, 3);
print_r($arr2);
$str = 'abc,中国,美国,日本';
// explode,是根据指定的分割符,把字符串拆成数组.
$arr = explode(',',$str);
print_r($arr);
// implode,是根据指定的连接符,把数组再拼接成字符串
$arr = explode(',',$str);
echo implode('~',$arr),'<br />';
// 你可以只传一个数组做参数,不指定连接符,
// 这样,将把数组单元直接拼接起来
echo implode($arr);
//3.html与字符串相互转化
$str = "hello ', world";
echo stripslashes($str),'<br />';
$str = '<ab>';
echo $str,'<br />';
echo htmlspecialchars($str);
//4.填充和剔除字符串
$str = '12345678';
echo chunk_split($str,3,',');
echo "<br>";
$text = "\t\tThese are a few words :) ... ";
echo trim($text);
echo "<br>";
echo str_pad('apple', 6)."is good.";
//5.查找替换截取
$substr = "index.html";
$log = <<< logfile
192.168.1.11:/www/htdocs/index.html:[2016/08/10:21:58:27]
192.168.1.11:/www/htdocs/index.html:[2016/08/18:01:51:37]
192.168.1.11:/www/htdocs/index.html:[2016/08/20:11:48:27]
logfile;
//7.大小写处理
$pos =strpos($log, $substr);
$pos2=strpos($log,"\n",$pos);
$pos=$pos+strlen($substr)+1;
$timestamp=substr($log,$pos,$pos2-$pos);
echo "The file $substr was first accessed on:$timestamp";
echo "<br>";
$author="lester@example.com";
$author=str_replace("@", "at", $author);
echo "connect the author of this article at $author";
echo "<br>";
echo ltrim(strstr($author,"@"), "@");
//8. json 数据和数组，对象互转
$str = 'aAAbbbb';
//print_r(strtolower($str)); //全部转小写
//print_r(strtoupper($str));//全部转大写
print_r(ucfirst($str));//首字母大写
echo "<br>";
echo $str ;
echo "<br>";
$str = "This is some <b>bold</b> text.";
echo $str;
echo '<br>';
echo htmlspecialchars($str);
$sub = 'php html java android ';
echo '<br>';
echo strstr("I love Shanghai!","Shanghai");
echo '<br>';
print_r(str_replace('html','xxxx',$sub ));
echo '<br>';
echo '<br>';
$book = array('name'=>'jack','age'=>30,'work'=>'老师','tacher'=>'php');
$json = json_encode($book);
echo $json;
echo '<br>';
print_r(json_decode($json));
//parse_str与http_build_query的使用
//使用parse_str将url字符串转变为key=>value的数组
$str = "tn=monline_dg&ie=utf-8&bs=httpbuildurl&f=3&rsv_bp=1&wd=php+buildquery&rsv_sug3=17&rsv_sug4=330&rsv_sug1=16&oq=php+build&rsv_sug2=0&rsp=0&inputT=8922";
parse_str($str,$arr);
var_dump($arr);
/*
输出：
array (
'tn' => 'monline_dg',
'ie' => 'utf-8',
'bs' => 'httpbuildurl',
'f' => '3',
'rsv_bp' => '1',
'wd' => 'php buildquery',
'rsv_sug3' => '17',
'rsv_sug4' => '330',
'rsv_sug1' => '16',
'oq' => 'php build',
'rsv_sug2' => '0',
'rsp' => '0',
'inputT' => '8922',
)
*/
//使用http_build_query将key=>value的数组转变为url字符串
$url = http_build_query($arr);
echo($url);
//输出：tn=monline_dg&ie=utf-8&bs=httpbuildurl&f=3&rsv_bp=1&wd=php+buildquery&rsv_sug3=17&rsv_sug4=330&rsv_sug1=16&oq=php+build&rsv_sug2=0&rsp=0&inputT=8922
批改老师：天蓬老师批改时间：2018-11-12 14:03:20
老师总结：使用array()函数来创建数组,是一种非常古老的方式了,建议不要再使用了
,在编程中,字符串是最常用的操作之一,必须掌握
