php strstr查找字符串中是否包含某些字符

<?php
/**
* 以下函数均可用来判断某字符串是否包含另外一个字符串
* php 中判断一个字符串是否包含其它字符是很常见的操作。
* 虽然很简单，但还是写了几个函数，质量可能不是很高，权当锻炼。
* 如果这几个函数恰好能帮上你的忙，我将会很高兴的。
*/
/**
* 利用一下 strpos() 函数
* @param unknown_type $haystack
* @param unknown_type $needle
*/
function isinstring1($haystack, $needle) {
//防止$needle 位于开始的位置
$haystack = '-_-!' . $haystack;
return (bool)strpos($haystack, $needle);
}
/**
* 利用字符串分割
* @param unknown_type $haystack
* @param unknown_type $needle
*/
function isinstring2($haystack, $needle) {
$array = explode($needle, $haystack);
return count($array) > 1;
}
/**
* 用了一下正则，这种方法十分不建议，尤其是 $needle 中包含
* 特殊字符，如 ^,$,/ 等等
* @param unknown_type $haystack
* @param unknown_type $needle
*/
function isinstring3($haystack, $needle) {
$pattern = '/' . $needle . '/';
return (bool)preg_match($pattern, $haystack);
}
/**
* 利用一下 strpos() 函数
* @param unknown_type $haystack
* @param unknown_type $needle
*/
function isinstring4($haystack, $needle) {
return false !== strpos($haystack, $needle);
}
//测试
$haystack = 'i am itbdw';
$needle = 'it';
var_dump(isinstring1($haystack, $needle));

<?php
echo strstr("hello world!","world");
?>
//输出：world!

<?php
echo strstr("hello world!",111);
?>
//输出：o world!

<?php
$email = 'admin@jb200.com';
$domain = strstr($email, '@');
echo $domain; // prints @jb51.net

$user = strstr($email, '@', true); // as of php 5.3.0
echo $user; // prints admin

$city_str=fopen(cgi_path."/data/weather/city.dat","r");
$city_ch=fread($city_str,filesize(cgi_path."/data/weather/city.dat"));
$city_ch_arr=explode("|",$city_ch);
//如果能匹配到所在市
if(strstr($area_ga,"市")){
foreach($city_ch_arr as $city_ch_arr_item){
if(@strstr($area_ga,$city_ch_arr_item)){
echo $area_ga.'<br>';
echo $city_ch_arr_item;
$s_city=$city_ch_arr_item;
}
} //脚本学堂 http://www.jb200.com
}
//如果找不到市 那么看看是不是能找到省 有时会有这样的情况：广东省长城宽带 这样的一律归属到该省省府
elseif(strstr($area_ga,"河北")!==false){
$s_city="石家庄";
}elseif(strstr($area_ga,"福建")!==false){
$s_city="福州";
}elseif(strstr($area_ga,"台湾")!==false){
$s_city="台北";
}elseif(strstr($area_ga,"香港")!==false){
$s_city="香港";
}elseif(strstr($area_ga,"广西")!==false){
$s_city="南宁";
}elseif(strstr($area_ga,"浙江")!==false){
$s_city="杭州";
}elseif(strstr($area_ga,"江苏")!==false){
$s_city="南京";
}elseif(strstr($area_ga,"山东")!==false){
$s_city="济南";
}elseif(strstr($area_ga,"安徽")!==false){
$s_city="合肥";
}elseif(strstr($area_ga,"湖南")!==false){
$s_city="长沙";
}elseif(strstr($area_ga,"四川")!==false){
$s_city="成都";
}elseif(strstr($area_ga,"云南")!==false){
$s_city="昆明";
}elseif(strstr($area_ga,"广东")!==false){
$s_city="广州";
}elseif(strstr($area_ga,"贵州")!==false){
$s_city="贵阳";
}elseif(strstr($area_ga,"西藏")!==false){
$s_city="拉萨";
}elseif(strstr($area_ga,"新疆")!==false){
$s_city="乌鲁木齐";
}elseif(strstr($area_ga,"蒙古")!==false){
$s_city="呼和浩特";
}elseif(strstr($area_ga,"黑龙江")!==false){
$s_city="哈尔滨";
}elseif(strstr($area_ga,"辽宁")!==false){
$s_city="沈阳";
}elseif(strstr($area_ga,"吉林")!==false){
$s_city="长春";
}elseif(strstr($area_ga,"河南")!==false){
$s_city="郑州";
}elseif(strstr($area_ga,"湖北")!==false){
$s_city="武汉";
}elseif(strstr($area_ga,"山西")!==false){
$s_city="太原";
}elseif(strstr($area_ga,"陕西")!==false){
$s_city="西安";
}elseif(strstr($area_ga,"甘肃")!==false){
$s_city="兰州";
}elseif(strstr($area_ga,"宁夏")!==false){
$s_city="银川";
}elseif(strstr($area_ga,"海南")!==false){
$s_city="海口";
}elseif(strstr($area_ga,"江西")!==false){
$s_city="南昌";
}elseif(strstr($area_ga,"澳门")!==false){
$s_city="澳门";
}
//如果都不存在 就是默认显示广州 比如本地机
else{
$s_city="广州";
}

<?php
echo strstr('aaaaaaaaaaaboaaaaaaaaaaaaboxcccccccccbcccccccccccccc','box')."<br>n";
//输出boxcccccccccbcccccccccccccc
// 完整匹配中间的box 不因前而的b而停止
echo strstr('aaaaaaabaaa aaaa aaaaaaaaaboxccccccccccccboxccccccccccc','box')."<br>n";
//输出boxccccccccccccboxccccccccccc
// 有两个关键字时, 遇到第一个停止.
echo strstr('subscrtibe our to free newsletter about new freew to','to')."<br>n";
//输出to free newsletter about new freew to
?>