$arr=array(2010,2011,2012,2013,2014,2015,2016,2017,2018,2019,2020);
$count=0;
foreach ($arr as $key=>$value){
    
                     //循环遍历
    if($value%4==0 && $value%100!=0 || $value%400==0){
    
                  //条件
        $count++;                   //因要统计闰年的个数，所以++
      echo $value;                  //输出数组的值
      echo "<br>";
    }
}
echo $count;                    //输出闰年的个数