//删除两边(单边)空格或其它预定义字符$str = '##hello world@@';echo trim($str,'#,@').'
'; //hello worldecho ltrim($str,'#').'
'; //hello world@@echo rtrim($str,'@').'
'; //##hello world
//返回路径中的目录部分echo dirname('c:/testweb/home.php').'
'; //c:/testweb
//把字符串填充为指定的字符串中$str = 'hello world';echo str_pad($str,20,'.',STR_PAD_BOTH).'
'; //....hello world.....echo str_pad($str,20,'.',STR_PAD_LEFT).'
'; //.........hello worldecho str_pad($str,20,'.',STR_PAD_RIGHT).'
'; //hello world.........
//把字符串分割到数组中(包含空格,一个空格为1个字符)$str = 'my name is Junjun Liu';$str1 = str_split($str,3);print_r($str1); //Array ( [0] => my [1] => nam [2] => e i [3] => s J [4] => unj [5] => un [6] => Liu )
//反转字符串$str = 'imagecreatetruecolor';echo strrev($str).'
'; //roloceurtetaercegami
//按照指定长度对字符串进行拆行处理$str = 'An example on a long word is: Supercalifragulisticlasdkjflasdjfalsdkakd';echo wordwrap($str,20, '
');
//将字符串解析成变量$str = 'first=value&arr[]=foo+bar&arr[]=baz';parse_str($str);echo $first.'
'; // valueecho $arr[0].'
'; // foo barecho $arr[1].'
'; // bazprint_r($arr); //Array ( [0] => foo bar [1] => baz )
//通过千分位组来格式化数字echo number_format('1000000'); //1,000,000echo number_format('1000000',2); //1,000,000.00echo number_format('1000000',2,',','.'); //1.000.000,00
//大小写转换echo strtolower('NAME'); //nameecho strtoupper('name'); //NAMEecho ucfirst('my name is Junjun Liu'); //My name is Junjun Liuecho ucwords('my name is Junjun Liu'); //My Name Is Junjun Liu
//预定义字符转html编码htmlspecialchars($str);echo '
';
//剥去HTML,XML,PHP的标签$str='asdasd
woaini
';echo strip_tags($str); //asdasdwoainiecho '';
//在指定的字符前添加反斜线转义字符串中字符$str = 'Hello, My name is John Adams.';echo addcslashes($str,'m'); //Hello, \my na\me is John Ada\ms //删除addcslashes反斜线echo stripcslashes($str); //Hello, my name is John Adams.echo '
';//指定预定义字符前添加反斜线$str = 'Who's John Ad\ams?';$str = addslashes($str); echo $str; //Who\'s John Adams?//删除反斜线 echo stripslashes($str).'
'; //Who's John Adams?
echo '不区分大小写比较两字符串:'.strcasecmp('abc','abd').'
'; //-1echo '区别大小写比较两字符串:' .strcmp('abd','Abd').'
'; //1
echo '区别大小写比较两字符串:' .strncmp('abcd','abcc',2).'
'; //0 /* 2是比较前n个字符串大小 */echo '不区分大小写比较两字符串:'.strncasecmp('abcd','abcc',4).'
'; //1
echo '区分大小(按自然顺序)写比较两字符串:'.strnatcmp('abc2','abc12').'
'; //-1echo '不区分大小(按自然顺序)写比较两字符串:'.strnatcasecmp('Abc8','abc12').'
'; //-1
//将字符串分成小块(空格也算)$str='hello world hello world';echo chunk_split($str,2,'#'); //he#ll#o #wo#rl#d #he#ll#o #wo#rl#d#
//切开字符串$first_token = strtok('/something', '/');$second_token = strtok('/');var_dump($first_token); //string(9) 'something'var_dump($second_token); //bool(false) //var_dump($first_token,$second_token);(同时打印两个变量)$str = 'This is an /example string';$tok = strtok($str,'/'); //This is anecho $tok;$str = 'Thisisan /example string';$tok = strtok($str,'/'); //Thisisanecho $tok;
//将数组值用预订字符连接成字符串$array = array('lastname', 'email', 'phone');$a = implode(',', $array);echo $a; // lastname,email,phone
//截取字符串$str = 'absadf';echo substr($str,2,3); //sadecho substr($str,-4,-1);//sad
//字符串替换操作,区分大小写 str_replace(被换字体,换成的字串,原字串)$str = '1,2,3:4,5:6';echo str_replace(',',':',$str).'
'; //1:2:3:4:5:6echo str_replace(array(',',':'),';',$str).'
'; //1;2;3;4;5;6echo str_replace(array(',',':'),array(';','#'),$str).'
'; //1;2;3#4;5#6
//统计一个字符串在另一个字符串中出现的次数substr_count(在此字符串中搜索,被搜索的字符串,开始偏移的位置,指定偏移的最大位置)$str1 = 'name';$str2 = 'my name isname name';echo substr_count($str2,$str1); //2
//返回两字符串相似度$str1 = 'abcdefgadfsa';$str2 = 'acdrgwsaasdf';echo ((similar_text($str1,$str2)/strlen($str1))*100).'%'.'
'; //58.333333333333%
//字串查找$str = 'zhangsan';echo strstr($str,'a').'
'; //angsan 从前面开始找a出现的位置并截取到最后(默认false)别名:strchr()echo strstr($str,'a',true).'
'; //zh 从前面开始找a出现的位置并向前截取echo strrchr($str,'a').'
'; //an 从后面开始找a并截取到最后echo strpos($str,'a').'
'; //2 获取字符串首次出现a的位置echo strpos($str,'a',3).'
'; //6 从3位置开始获取字符串出现a的位置echo strrpos($str,'a').'
'; //6 获取字符串中a最后一次出现的位置
//统计字符串长度$str = ' ab cd ';echo strlen($str); // 7