<?php
$username="ginoSin";
#判断参数是否只在a-z范围
if(ereg("([^a-z])",$username))
{
echo "username must be all lowercase";
}
else
{
echo "username is all lowercase";
}
echo "<br>";
#输出字符参数的长度
echo "the length of $username is:".strlen($username);
#比较字符与参数是否相等,区分大小写比较strcmp(),不区分大小写strcasecmp()
if(strcmp($username,"ginosin")!=0)
{
echo "<br>that is equal!";
}
#求两个字符相同的部分的长度 strspn(),不同的部分strcspn()
echo "<br>".strspn($username,"ginoEnn");
#转换成小写 strtolower
#转换成大写 strtoupper
#第一个字符大写 ucfirst()
#每个单词变为大写 ucwords()
#nl2br()将\n转换为br
$recipe="<br>"."one day,
i remember to buy
a book of php";
echo nl2br($recipe);
#htmlentities() 特殊字符等价转换成html
#htmlspecialchars()
#get_html_translation_table()
#array_flip()反转特殊字符
#自定义转换 strtr
$table=array("<b>"=>"<strong>","</b>"=>"</strong>");
$html="<b>No smoking</b>";
echo "<p>".strtr($html,$table)."</p>";
#html转换成纯文本,去掉html标签 strip_tags()
$input="<a href='http://cnblogs.com/tomieric'>tomieric</a> Document.";
echo strip_tags($input); //去掉所有标签
echo strip_tags($input,"<a>"); //只去掉a
#分解字符串 explode(),split()
echo "<p>";
$newstr=explode(" ","i'm a geek");
//print_r $newstr
echo "</p>";
#将数组转换为字符串implode
$goods=array("banana","apple","pear");
echo "<p>".implode(";",$goods)."</p>";
#strpos(str,substr[,int offset])区分大小写查找substr第一次出现
#strrpos()最后一次出现
#查找替换
$author="tomieric@gmail.com";
$author=str_replace("@","(at)",$author);
echo "<p>".$author."</p>";
#从某字符开始截取后面的部分
$author="tomieric@gmail.com";
//echo "<p>".ltrim(strstr($author,"@"),"@")."</p>"; //output "gmail.com"
echo "<p>".strstr($author,"@")."</p>"; //output "@gmail.com"
#预定位置截取字符串 substr(str,start[,length])
echo "<p>".substr($author,0,8)."</p>";
#substr_count(str,substring) 确定字符串出现频率
#替换substr_replace(str,replacement,start[,length])
$phoneNumber="15952341523";
echo "<p>".substr_replace($phoneNumber,"135",0,3)."</p>";
#ltrim(str,charlist) 从字符开始处截取
ltrim($email,"@"); //return gmail.com
#rtrim(str,charlist) 从字符右侧开始截取
rtrim($emai,"@"); //return tomieric
#trim(str,charlist) 从两侧截取
#str_pad(str,length,type) 填充 默认空格填充
#count_chars(str,[,mode])字符统计
#str_word_count(str,[,format])单词统计
?>