Object-Oriented Data-Structures - A Concise and Practical Introduction to Programming Algorithms in Java - page 186

- Pull (or Pop ): Remove the last inserted element from the stack.

These two basic methods of stacks can be implemented using various schemes.
We describe two of them to insist on the notion of abstract data-structures:
Arrays and linked lists.

8.6.1 Stack interface and an array implementation

We may implement a stack using an array. The array is declared as an object
field with an index variable that indicates the position of the last inserted
element: the top of the stack. The Push / Pull primitives of the stack interface
are then implemented as follows:

Program 8.15 Stack implementation using an array
class StackArray
int nbmax ;
int index ;
int [

] array ;

// Constructors
StackArray( int n)
this . nbmax=n ;
array= new i n t [ nbmax ] ;

1;
System . out . println ( "Succesfully created a stack array object
..." );

index = −

}

// Methods
void Push( int element)
if (index < nbmax − 1)
array[++index]=element ;

}

int Pull ()
if (index > =0 ) return array [ index −− ];
else return − 1;
}

}

Let us store the above StackArray class into a corresponding Java source code
text file: StackArray.java . Then compile this code for manipulating stacks
using arrays:
prompt% javac StackArray.java