php从数组中获得一个随机元素的方法

$option = array('广www.111cn.net词1','广告词2','广告词3','广告词4','广告词5');

$index = rand(0, count($option)-1);
echo $option[$index];

<?php
$a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse");
print_r(array_rand($a,1));
?>

$file_path = '123.txt';
$content = file_get_contents($file_path);
//按换行符把全部内容分隔成数组
$con_array = explode("n", $content);
//替换掉指定行
    
$con_array[12]="123";
//组合回字符串
$con = implode("n", $con_array);
    
//写回文档
file_put_contents($file_path, $con);

Array
(
    [type] => 8
    [message] => Undefined variable: http://www.111cn.net
    [file] => C:WWWindex.php
    [line] => 2
)

error_reporting(E_ALL); //E_ALL
 
function cache_shutdown_error() {
 
    $_error = error_get_last();
 
    if ($_error && in_array($_error['type'], array(1, 4, 16, 64, 256, 4096, E_ALL))) {
 
        echo '<font color=red>你的代码出错了：</font></br>';
        echo '致命错误:' . $_error['message'] . '</br>';
        echo '文件:' . $_error['file'] . '</br>';
        echo '在第' . $_error['line'] . '行</br>';
    }
}
 
register_shutdown_function("cache_shutdown_error");

display_errors = Off
error_reporting = E_ALL & ~E_NOTICE

display_errors = On

<?php
//禁用错误报告
error_reporting(0);
//报告运行时错误
error_reporting(E_ERROR | E_WARNING | E_PARSE);
//报告所有错误
error_reporting(E_ALL);
?>

function getmicrotime() 
{ 
    list($usec, $sec) = explode(" ",microtime()); 
    return ((float)$usec + (float)$sec); 
}

<?php
/**
* Simple function to replicate PHP 5 behaviour
*/
function microtime_float()
{
    list($usec, $sec) = explode(" ", microtime());
    return ((float)$usec + (float)$sec);
}

$time_start = microtime_float();

// Sleep for a while
usleep(100);

$time_end = microtime_float();
$time = $time_end - $time_start;

echo "Did nothing in $time secondsn";
?>

    /*
    * @Author： vfhky 2013年09月21日22:13
    * @Variable string $word: 黑名单中的关键词，用户可自行按规律进行增加或减少
    * @Variable string $comment_author: 用户提交的$_POST['author']字段值，表示昵称
    * @Variable string $comment_content: 用户提交的$_POST['comment']字段值，表示评论内容
    **/
    $words = "com,cn,info,net,www,http,cc,host,代理,移动,电,国,港,器,服,医,肥,药,农,信,贷,日,盈,网,票,域,销,黄,司,企,机,租,人,钱,设,购,播";
    $word = explode(',', $words);
    $num = count($word);
    for($i=0;$i< $num ;$i++){
    if (strpos($comment_author,$word[$i],0) || strpos($comment_content,$word[$i],0)){
    err( __('广告必删，多谢理解!') );
    break;
    }
    }

    /*
    * @Author： vfhky 2013年09月24日20:06
    * @Description: 正确使用strpos函数，解决上一篇文章代码的BUG
   
    **/
    $words = "com,cn,info,net,www,http,cc,host,代理,移动,电,国,港,器,服,医,肥,药,农,信,贷,日,购,播";
    $word = explode(',', $words);
    $num = count($word);
    for($i=0;$i< $num ;$i++){
    if ( (strpos($comment_author,$word[$i],0) !== false) || (strpos($comment_content,$word[$i],0) !== false) ){
    err( __('广告必删，多谢理解!') );
    break;
    }
    }

    $words = array("com","cn","info","net","www","http","cc","host","代理","移动","电","国","港","购");
    $num = count($words);
    for($i=0;$i< $num ;$i++){
    if (strpos($comment_author,$words[$i],0) !== false || strpos($comment_content,$words[$i],0) !== false){
    err( __('广告必删，多谢理解!') );
    break;
    }
    }