9个比较实用的php代码片段，_PHP教程

$meta = get_meta_tags('http://www.emoticode.net/');
$keywords = $meta['keywords'];
// Split keywords
$keywords = explode(',', $keywords );
// Trim them
$keywords = array_map( 'trim', $keywords );
// Remove empty values
$keywords = array_filter( $keywords );

print_r( $keywords );

$html = file_get_contents('http://www.example.com');
 
$dom = new DOMDocument();
@$dom->loadHTML($html);
 
// grab all the on the page
$xpath = new DOMXPath($dom);
$hrefs = $xpath->evaluate("/html/body//a");
 
for ($i = 0; $i < $hrefs->length; $i++) {
$href = $hrefs->item($i);
$url = $href->getAttribute('href');
echo $url.'<br />';
}

function data_uri($file, $mime) {
  $contents=file_get_contents($file);
  $base64=base64_encode($contents);
  echo "data:$mime;base64,$base64";
}

$image = file_get_contents('http://www.php100.com/image.jpg');
file_put_contents('/images/image.jpg', $image);  //Where to save the image

function cleanHTML($html) {
/// 
/// Removes all FONT and SPAN tags, and all Class and Style attributes.
/// Designed to get rid of non-standard Microsoft Word HTML tags.
/// 
// start by completely removing all unwanted tags

$html = ereg_replace("<(/)&#63;(font|span|del|ins)[^>]*>","",$html);

// then run another pass over the html (twice), removing unwanted attributes

$html = ereg_replace("<([^>]*)(class|lang|style|size|face)=("[^"]*"|'[^']*'|[^>]+)([^>]*)>","<\1>",$html);
$html = ereg_replace("<([^>]*)(class|lang|style|size|face)=("[^"]*"|'[^']*'|[^>]+)([^>]*)>","<\1>",$html);

return $html
}

function get_client_language($availableLanguages, $default='en'){
  if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
     $langs=explode(',',$_SERVER['HTTP_ACCEPT_LANGUAGE']);

     foreach ($langs as $value){
       $choice=substr($value,0,2);
       if(in_array($choice, $availableLanguages)){
          return $choice;
       }
     }
   } 
   return $default;
}

//如果去获取某个excel日期（格式为：2016-03-12），那么获取到的是数字，需要经过转换才能恢复
public function excelTime($date, $time = false) {

      if(function_exists('GregorianToJD')){

        if (is_numeric( $date )) {

        $jd = GregorianToJD( 1, 1, 1970 );

        $gregorian = JDToGregorian( $jd + intval ( $date ) - 25569 );

        $date = explode( '/', $gregorian );

        $date_str = str_pad( $date [2], 4, '0', STR_PAD_LEFT )

        ."-". str_pad( $date [0], 2, '0', STR_PAD_LEFT )

        ."-". str_pad( $date [1], 2, '0', STR_PAD_LEFT )

        . ($time ? " 00:00:00" : '');

        return $date_str;
        }

      }else{

        // $date=$date>25568? $date+1:25569;

        /*There was a bug if Converting date before 1-1-1970 (tstamp 0)*/

        $ofs=(70 * 365 + 17+2) * 86400;

        $date = date("Y-m-d",($date * 86400) - $ofs).($time ? " 00:00:00" : '');
        return $date;
      }

  }

1 json转换成数组
$json = '[{"id":"22","name":"33","descn":"44"}]'; //json格式的数组转换成 php的数组
$arr = (Array)json_decode($json);
echo $arr[0]->id; //用对象的方式访问（这种是没有转换成数组，而是转换成对象的情况

2 数组转换成json
$json_arr = array('WebName'=>'11','WebSite'=>'11');
$php_json = json_encode($json_arr); //把php数组格式转换成 json 格式的数据
echo $php_json;