Containers O Hold a group of objects o Significantly increase your programming power OAll perform bound checking ● array:efficient,can hold primitives Collection:a group of individual elements OList,Set o Map:a group of key-value object pairs OHashMap o Misleading:sometimes the whole container libraries are also called collection classesContainers l Hold a group of objects l Significantly increase your programming power l All perform bound checking l array: efficient, can hold primitives l Collection: a group of individual elements ¡List, Set l Map: a group of key-value object pairs ¡HashMap l Misleading: sometimes the whole container libraries are also called collection classes