AggregateOperand.Count Method

Name	Parameters	Description
Count()	none	Initializes a new AggregateOperand instance that evaluates the count of objects in the collection. The new operand computes the aggregate value against elements of the current operand’s CollectionProperty that match the current operand’s Condition.
Count(CriteriaOperator)	aggregatedExpression	Initializes a new AggregateOperand instance that evaluates the count of objects in the collection. The new operand computes the aggregate value against elements of the current operand’s CollectionProperty that match the current operand’s Condition.