根据生日获取年龄

/** 
     * @uses 根据生日计算年龄，年龄的格式是：2016-09-23 
     * @param string $birthday 
     * @return string|number 
     */  
    public function calcAge($birthday) {  
        $iage = 0;  
        if (!empty($birthday)) {  
            $year = date(‘Y‘,strtotime($birthday));  
            $month = date(‘m‘,strtotime($birthday));  
            $day = date(‘d‘,strtotime($birthday));  
              
            $now_year = date(‘Y‘);  
            $now_month = date(‘m‘);  
            $now_day = date(‘d‘);  
      
            if ($now_year > $year) {  
                $iage = $now_year - $year - 1;  
                if ($now_month > $month) {  
                    $iage++;  
                } else if ($now_month == $month) {  
                    if ($now_day >= $day) {  
                        $iage++;  
                    }  
                }  
            }  
        }  
        return $iage;  
    }  

public function calcAge($birthday) {  
        $age = 0;  
        if(!empty($birthday)){  
            $age = strtotime($birthday);  
            if($age === false){  
                return 0;  
            }  
              
            list($y1,$m1,$d1) = explode("-",date("Y-m-d", $age));  
              
            list($y2,$m2,$d2) = explode("-",date("Y-m-d"), time());  
              
            $age = $y2 - $y1;  
            if((int)($m2.$d2) < (int)($m1.$d1)){  
                $age -= 1;  
            }  
        }  
        return $age;  
    }