Collection<T>::Contains Method (T)

Parameters

item

Type: T

The object to locate in the Collection<T>. The value can be null for reference types.

Return Value

true if item is found in the Collection<T>; otherwise, false.

Implements

If the Collection<T> object is created using the default constructor, this method determines equality using the default equality comparer EqualityComparer<T>::Default for T, the type of values in the list. If type T does not implement the IEquatable<T> interface, the Equals method is used.

If the Collection object is created by passing an IList<T> object to the constructor, the Contains method will be determined by the IEqualityComparer<T> interface used by that IList<T> object.

This method performs a linear search; therefore, the average execution time is proportional to Count. That is, this method is an O(n) operation, where n is Count.