常用方法

1.
/**
 * 友好时间
 */
function fdate($time) {
    if (! $time)
        return false;
    $fdate = '' ;
    $d = time() - intval($time);
    $ld = $time - mktime(0 , 0, 0, 0 , 0, date('Y' )); //年
    $md = $time - mktime( 0, 0 , 0, date('m' ), 0, date('Y' )); //月
    $byd = $time - mktime( 0, 0 , 0, date('m' ), date( 'd') - 2, date('Y' )); //前天
    $yd = $time - mktime( 0, 0 , 0, date('m' ), date( 'd') - 1, date('Y' )); //昨天
    $dd = $time - mktime( 0, 0 , 0, date('m' ), date( 'd'), date('Y' )); //今天
    $td = $time - mktime( 0, 0 , 0, date('m' ), date( 'd') + 1, date('Y' )); //明天
    $atd = $time - mktime( 0, 0 , 0, date('m' ), date( 'd') + 2, date('Y' )); //后天
    if ($d == 0) {
        $fdate = '刚刚' ;
    } else {
        switch ($d) {
            case $d < $atd:
                $fdate = date( 'Y年m月d日' , $time);
                break;
            case $d < $td:
                $fdate = '后天' . date ('H:i', $time);
                break;
            case $d < 0:
                $fdate = '明天' . date ('H:i', $time);
                break;
            case $d < 60:
                $fdate = $d . '秒前';
                break;
            case $d < 3600:
                $fdate = floor($d / 60) . '分钟前';
                break;
            case $d < $dd:
                $fdate = floor($d / 3600) . '小时前';
                break;
            case $d < $yd:
                $fdate = '昨天' . date ('H:i', $time);
                break;
            case $d < $byd:
                $fdate = '前天' . date ('H:i', $time);
                break;
            case $d < $md:
                $fdate = date( 'm月d H:i', $time);
                break;
            case $d < $ld:
                $fdate = date( 'm月d', $time);
                break;
            default:
                $fdate = date( 'Y年m月d日' , $time);
                break;
        }
    }
    return $fdate;
}

/**
 * 靓号分隔
 * Enter description here ...
 * @param unknown_type $num
 */
function phone_number_format($num){
      $number1 = substr($num , 0,3 );
      $number2 = substr($num , 3,4 );
      $number3 = substr($num , 7,4 );
      $number  = $number1.' ' .$number2.' '.$number3;
      return $number;
}

2.
function format_price($price)
{
      return '￥' .''. round($price,2 );
}

3.
//utf8 字符串截取
function msubstr($str, $start =0, $length =15, $charset ="utf-8", $suffix=false)
{
      if(function_exists ("mb_substr"))
    {
        $slice =  mb_substr($str, $start, $length, $charset);
        if($suffix& $slice!=$str) return $slice."…" ;
      return $slice;
    }
    elseif(function_exists ('iconv_substr')) {
        return iconv_substr($str,$start,$length,$charset);
    }
    $re ['utf-8']   = "/[x01- x7f]|[xc2 -xdf][ x80-xbf ]|[xe0- xef][x80 -xbf]{2}|[ xf0-xff ][x80- xbf]{3}/";
    $re ['gb2312'] = "/[x01 -x7f]|[ xb0-xf7 ][xa0- xfe]/";
    $re ['gbk']    = "/[x01 -x7f]|[ x81-xfe ][x40- xfe]/";
    $re ['big5']   = "/[x01- x7f]|[x81 -xfe]([ x40-x7e ]|xa1- xfe])/";
    preg_match_all($re[ $charset], $str, $match);
    $slice = join( "",array_slice ($match[0 ], $start, $length));
    if($suffix&& $slice!=$str) return $slice."…" ;
    return $slice;
}

4.
/**
  * 生成随机字串
  * @param number $length 长度，默认为16，最长为32字节
  * @return string
  */
public function generateNonceStr($length =16){
            // 密码字符集，可任意添加你需要的字符
            $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" ;
           $str = "" ;
            for($i = 0; $i < $length; $i++)
           {
                $str .= $chars [mt_rand( 0, strlen ($chars) - 1 )];
           }
            return $str;
}

/**
  * 获取毫秒级别的时间戳
  */
private static function getMillisecond()
{
        //获取毫秒的时间戳
        $time = explode ( " ", microtime () );
        $time = $time[1] . ($time[0] * 1000);
        $time2 = explode( ".", $time );
        $time = $time2[0];
        return $time;
}  

5.
/**
 * 获取数组中的某一列
 * @param type $arr 数组
 * @param type $key_name  列名
 * @return type  返回那一列的数组
 */
function get_arr_column($arr, $key_name)
{
    $arr2 = array();
    foreach($arr as $key => $val){
        $arr2[] = $val[$key_name];        
    }
    return $arr2;
}  

6.
/**
 * 将二维数组以元素的某个值作为键 并归类数组
 * array( array('name'=>'aa','type'=>'pay'), array('name'=>'cc','type'=>'pay') )
 * array('pay'=>array( array('name'=>'aa','type'=>'pay') , array('name'=>'cc','type'=>'pay') ))
 * @param $arr 数组
 * @param $key 分组值的key
 * @return array
 */
function group_same_key($arr,$key){
    $new_arr = array();
    foreach($arr as $k=>$v ){
        $new_arr[$v[$key]][] = $v;
    }
    return $new_arr;
}  

7.
/**
 * 过滤数组元素前后空格 (支持多维数组)
 * @param $array 要过滤的数组
 * @return array|string
 */
function trim_array_element($array){
    if(!is_array($array))
        return trim($array);
    return array_map('trim_array_element',$array);
}  


8.
//php获取中文字符拼音首字母
function getFirstCharter($str){
      if(empty($str))
      {
            return '';          
      }
      $fchar=ord($str{0});
      if($fchar>=ord('A')&&$fchar<=ord('z')) return strtoupper($str{0});
      $s1=iconv('UTF-8','gb2312',$str);
      $s2=iconv('gb2312','UTF-8',$s1);
      $s=$s2==$str?$s1:$str;
      $asc=ord($s{0})*256+ord($s{1})-65536;
     if($asc>=-20319&&$asc<=-20284) return 'A';
     if($asc>=-20283&&$asc<=-19776) return 'B';
     if($asc>=-19775&&$asc<=-19219) return 'C';
     if($asc>=-19218&&$asc<=-18711) return 'D';
     if($asc>=-18710&&$asc<=-18527) return 'E';
     if($asc>=-18526&&$asc<=-18240) return 'F';
     if($asc>=-18239&&$asc<=-17923) return 'G';
     if($asc>=-17922&&$asc<=-17418) return 'H';
     if($asc>=-17417&&$asc<=-16475) return 'J';
     if($asc>=-16474&&$asc<=-16213) return 'K';
     if($asc>=-16212&&$asc<=-15641) return 'L';
     if($asc>=-15640&&$asc<=-15166) return 'M';
     if($asc>=-15165&&$asc<=-14923) return 'N';
     if($asc>=-14922&&$asc<=-14915) return 'O';
     if($asc>=-14914&&$asc<=-14631) return 'P';
     if($asc>=-14630&&$asc<=-14150) return 'Q';
     if($asc>=-14149&&$asc<=-14091) return 'R';
     if($asc>=-14090&&$asc<=-13319) return 'S';
     if($asc>=-13318&&$asc<=-12839) return 'T';
     if($asc>=-12838&&$asc<=-12557) return 'W';
     if($asc>=-12556&&$asc<=-11848) return 'X';
     if($asc>=-11847&&$asc<=-11056) return 'Y';
     if($asc>=-11055&&$asc<=-10247) return 'Z';
     return null;
}

9.
/**
 * 判断当前访问的用户是  PC端  还是 手机端  返回true 为手机端  false 为PC 端
 * @return boolean
 */
/**
　　* 是否移动端访问访问
　　*
　　* @return bool
　　*/
function isMobile()
{
        // 如果有HTTP_X_WAP_PROFILE则一定是移动设备
    if (isset ($_SERVER['HTTP_X_WAP_PROFILE']))
    return true;
    // 如果via信息含有wap则一定是移动设备,部分服务商会屏蔽该信息
    if (isset ($_SERVER['HTTP_VIA']))
    {
    // 找不到为flase,否则为true
    return stristr($_SERVER['HTTP_VIA'], "wap") ? true : false;
    }
    // 脑残法，判断手机发送的客户端标志,兼容性有待提高
    if (isset ($_SERVER['HTTP_USER_AGENT']))
    {
        $clientkeywords = array ('nokia','sony','ericsson','mot','samsung','htc','sgh','lg','sharp','sie-','philips','panasonic','alcatel','lenovo','iphone','ipod','blackberry','meizu','android','netfront','symbian','ucweb','windowsce','palm','operamini','operamobi','openwave','nexusone','cldc','midp','wap','mobile');
        // 从HTTP_USER_AGENT中查找手机浏览器的关键字
        if (preg_match("/(" . implode('|', $clientkeywords) . ")/i", strtolower($_SERVER['HTTP_USER_AGENT'])))
            return true;
    }
        // 协议法，因为有可能不准确，放到最后判断
    if (isset ($_SERVER['HTTP_ACCEPT']))
    {
    // 如果只支持wml并且不支持html那一定是移动设备
    // 如果支持wml和html但是wml在html之前则是移动设备
        if ((strpos($_SERVER['HTTP_ACCEPT'], 'vnd.wap.wml') !== false) && (strpos($_SERVER['HTTP_ACCEPT'], 'text/html') === false || (strpos($_SERVER['HTTP_ACCEPT'], 'vnd.wap.wml') < strpos($_SERVER['HTTP_ACCEPT'], 'text/html'))))
        {
            return true;
        }
    }
            return false;
 }