PHP字符串操作函数
<?php
/*
* @author gf
* 字符串操作函数
*/
header("content-type:text/html;charset='utf-8'");
/*
nl2br() 在字符串所有新行之前插入 HTML 换行标记
$str = "cat isn't \n dog";
$result = nl2br($str);
echo $result;
结果
cat isn't
dog
*/
/*
rtrim() chop() 清除结尾的空白
ltrim() 清除开头的空白
trim() 清除开头结尾的空白
$str = ' hello,php ';
$result = trim($str);
echo $result;
*/
/*
strip_tags() 清除字符串html和php的标记
$str = '<font color="blue">hello,phper</font>';
$result = strip_tags($str);
echo $result;
*/
/*
strtolower() 字符串转换成小写
strtoupper() 字符串转换成大写
$str = 'Hello ,PHPer';
$result = strtoupper($str);
echo $result;
*/
/*
str_repeat(string,int) 将一个字符串重复利用
$str = 'gaogaofeifei';
$result = str_repeat($str , 10);
echo $result;
*/
/*
str_replace(参数，参数，string) 区分大小写的替换
str_ireplace(参数,参数,string) 不区分大小写的替换字符串
$str = 'Gao fei';
$result1 = str_ireplace('gao','G',$str);
$result2 = str_replace('fei','G',$str);
echo $result1.'<br />';
echo $result2;
*/
/*
str_word_count(string)返回字符串中单词的个数
str_word_count(string,int)返回一个数组
$str = 'james is a bad boy';
$result = str_word_count($str,1);
$result2 = str_word_count($str);
var_dump($result);
echo $result2;
*/
/*
strlen(string)返回字符串长度
$str = 'this is PHP!!!!';
$result = strlen($str);
echo $result;
*/
/*
substr_count(string,string)计算一个字符串在另一个字符串的个数
$str = 'ni hao , wo shi pinyin ！！wo hahaha';
$result = substr_count($str , 'wo');
echo $result;
*/
/*
substr_replace(string,参数，位数)从哪个位置开始替换字符串
$str = 'zhe shi php yu yan ';
$result = substr_replace($str , 'yu' , 2);
echo $result;
*/
/*
substr(string,参数，参数)截取字符串
$str = 'this is php yuyan';
$result = substr($str , 0 , 2);
echo $result;
*/
/*
implode(参数，array) 将数组转换为字符串
join(参数,array) 将数组转换为字符串
explode(参数,string) 将字符串转为数组
$arr = array(1,2,3,4,5);
$string = implode("/",$arr);
echo $string;
$str = '1,2,3,4,5';
$result = explode(",",$str);
var_dump($result);
*/
/*
md5()对字符串进行加密，多用于密码 php函数库内暂无MD5解密函数
crypt()对字符串进行加密 单项函数 产生字符串比较复杂不易破解
$str = 'goafei';
$result = md5($str);
echo $result;
*/
/*
* strtr()函数转换字符串中特定的字符。
$trans = array("hello" => "hi", "hi" => "hello");
echo strtr("hi all, I said hello", $trans);
*/
/*
strstr()查找字符串的首次出现
$str = '82582785@qq.com';
$result = strstr($str,'@');
echo $result;
*/
/*
strcmp() 二进字符串比较
$str1 = 'this is string!';
$str2 = 'this is new string! ';
$result = strcmp($str2,$str1);
if($result != 0)
{
echo '123';
}
*/
/*
substr_count()
$str = 'this is is is ';
$result = substr_count($str,'is');
echo $result;
*/
/*
json_encode()将数组转换为json数据
json_decode()将json数据转换为数组
$arr = array(
'1' => 'gaofei',
'2' => 'james'
);
$json_data = json_encode($arr);
var_dump($json_data);
$array_data = json_decode($json_data);
var_dump($array_data);
*/
