php数组计数

I have a var dump of my sql query which return the following

I wanna to count in the array below that how many rows of myID = 5 are there. How would I do that. I am using php. Thanks in advance

 array
  0 => 
    object(stdClass)[17]

      public 'myID' => string '5' (length=1)
      public 'data' => string '123' (length=3)
  1 => 
    object(stdClass)[18]

      public 'myID' => string '5' (length=1)
      public 'data' => string '123' (length=3)
  2 => 
    object(stdClass)[19]

      public 'relativeTypeID' => string '2' (length=1)
      public 'data' => string '256' (length=3)
  3 => 
    object(stdClass)[20]

      public 'myID' => string '4' (length=1)
      public 'data' => string '786' (length=3)

    object(stdClass)[21]

      public 'myID' => string '4' (length=1)
      public 'data' => string '786' (length=3)

Do you always have the same value of data for the same myID? In other words, is data functionally dependant on myID?

If so, you can get the database to do this for you:

SELECT myID, data, COUNT(*) AS cnt
FROM (your query here)
GROUP BY myID, data

This would give you results like the following:

myID  data   cnt
'5'   '123'  3
'2'   '256'  1
'4'   '786'  2

Or, you can use a foreach statement, like:

$count = 0;

foreach($arr as $item)
{
    // Given that your item is an stdClass Object you access its property with "->"
    // if an array $item["myID"] instead
    if ( $item->myID == '4' )
    {
        $count ++;
    }
}