A stack is a limited version of an array. New elements or nodes as they are often Called, can be added to a stack and removed from a stack only from one end. For this reason, a stack is referred to as a LIFO structure (Last-In First-Out).
Mainly the following three basic operations are performed in the stack:
Push : adds a new node
Pop : removes a node
Peek : return the last element in the stack
Pop : removes a node
Stack (Last-In First-Out) |
Additional primitives can be defined:
IsEmpty : reports whether the stack is emptyPeek : return the last element in the stack
Stack Implementation
Consider a stack class stores data in an array (static structure). The array reference type is Object[] which means that it can contain any kind of Java object.When you run the program, the output will be:
Contents of Stack : 1 2 3 4 5Remove the top of stack element : 5Return the top stack element : 4Contents of Stack : 1 2 3 4