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)