<?php
echo strstr("Hello world!",111);
?>

<?php

echo strstr("Hello world!","world",true);

<?php
echo strstr("I love Shanghai!","Shanghai");
?>

<?php 
/** 
* 以下幾個函數(shù)均可用來判斷某字符串是否包含另外一個字符串 
* PHP 中判斷一個字符串是否包含其它字符是很常見的操作。 
* 雖然很簡單，但還是寫了幾個函數(shù)，質(zhì)量可能不是很高，權當鍛煉。 
* 如果這幾個函數(shù)恰好能幫上你的忙，我將會很高興的。 
*/ 
/** 
* 利用一下 strpos() 函數(shù) 
* @param unknown_type $haystack 
* @param unknown_type $needle 
*/ 
function isInString1($haystack, $needle) { 
//防止$needle 位于開始的位置 
$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) &gt; 1; 
} 
/** 
* 用了一下正則，這種方法十分不建議，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() 函數(shù) 
* @param unknown_type $haystack 
* @param unknown_type $needle 
*/ 
function isInString4($haystack, $needle) { 
return false !== strpos($haystack, $needle); 
} 
//測試 
$haystack = 'I am ITBDW'; 
$needle = 'IT'; 
var_dump(isInString1($haystack, $needle)); 

<?php 
echo strstr("Hello world!","world"); 
?> 

<?php 
echo strstr("Hello world!",111); 
?> 

<?php 
$email = 'admin@jb51.net'; 
$domain = strstr($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; 
} 
} 
} 
//如果找不到市 那么看看是不是能找到省 有時會有這樣的情況：廣東省長城寬帶 這樣的一律歸屬到該省省府 
elseif(strstr($area_ga,"河北")!==false){ 
$s_city="石家莊"; 
}elseif(strstr($area_ga,"福建")!==false){ 
$s_city="福州"; 
}elseif(strstr($area_ga,"臺灣")!==false){ 
$s_city="臺北"; 
}elseif(strstr($area_ga,"香港")!==false){ 
$s_city="香港"; 
}elseif(strstr($area_ga,"廣西")!==false){ 
$s_city="南寧"; 
}elseif(strstr($area_ga,"浙江")!==false){ 
$s_city="杭州"; 
}elseif(strstr($area_ga,"江蘇")!==false){ 
$s_city="南京"; 
}elseif(strstr($area_ga,"山東")!==false){ 
$s_city="濟南"; 
}elseif(strstr($area_ga,"安徽")!==false){ 
$s_city="合肥"; 
}elseif(strstr($area_ga,"湖南")!==false){ 
$s_city="長沙"; 
}elseif(strstr($area_ga,"四川")!==false){ 
$s_city="成都"; 
}elseif(strstr($area_ga,"云南")!==false){ 
$s_city="昆明"; 
}elseif(strstr($area_ga,"廣東")!==false){ 
$s_city="廣州"; 
}elseif(strstr($area_ga,"貴州")!==false){ 
$s_city="貴陽"; 
}elseif(strstr($area_ga,"西藏")!==false){ 
$s_city="拉薩"; 
}elseif(strstr($area_ga,"新疆")!==false){ 
$s_city="烏魯木齊"; 
}elseif(strstr($area_ga,"蒙古")!==false){ 
$s_city="呼和浩特"; 
}elseif(strstr($area_ga,"黑龍江")!==false){ 
$s_city="哈爾濱"; 
}elseif(strstr($area_ga,"遼寧")!==false){ 
$s_city="沈陽"; 
}elseif(strstr($area_ga,"吉林")!==false){ 
$s_city="長春"; 
}elseif(strstr($area_ga,"河南")!==false){ 
$s_city="鄭州"; 
}elseif(strstr($area_ga,"湖北")!==false){ 
$s_city="武漢"; 
}elseif(strstr($area_ga,"山西")!==false){ 
$s_city="太原"; 
}elseif(strstr($area_ga,"陜西")!==false){ 
$s_city="西安"; 
}elseif(strstr($area_ga,"甘肅")!==false){ 
$s_city="蘭州"; 
}elseif(strstr($area_ga,"寧夏")!==false){ 
$s_city="銀川"; 
}elseif(strstr($area_ga,"海南")!==false){ 
$s_city="海口"; 
}elseif(strstr($area_ga,"江西")!==false){ 
$s_city="南昌"; 
}elseif(strstr($area_ga,"澳門")!==false){ 
$s_city="澳門"; 
} 
//如果都不存在 就是默認顯示廣州 比如本地機 
else{ 
$s_city="廣州"; 
}

<?php 
echo strstr('aaaaaaaaaaaboaaaaaaaaaaaaboxcccccccccbcccccccccccccc','box')."<br>\n"; 
//輸出boxcccccccccbcccccccccccccc 
// 完整匹配中間的box 不因前而的b而停止 
echo strstr('aaaaaaAbaaa aaaa aaaaaaaaaboxccccccccccccboxccccccccccc','box')."<br>\n"; 
//輸出boxccccccccccccboxccccccccccc 
// 有兩個關鍵字時, 遇到第一個停止. 
echo strstr('Subscrtibe our to free newsletter about New Freew to','to')."<br>\n"; 
//輸出to free newsletter about New Freew to 
?>