Question

3 a) Design a search method using proper Java syntax with the signature shown below. Assume the books are stored in a stack (i.e., can only access an element before another after you pop the top). You can document any other assumptions you make using Java comments within the code Note. You can only access an element below another element by popping the stack. public Book Search (int ISBN)

Answer 1

public Book Search(int ISBN)

{

    // assuming the stack is defined using variable stk

   

    // loop untill the tack is empty

    // isEmpty() returns true if the stack is empty

    while( !stk.isEmpty() )

    {

        // get the topmost element from stack

        Book ob = stk.top();

       

        // if the current object is the required object

        // getISBN() function returns the ISBN value of book

        if( ob.getISBN() == ISBN )

            return ob;

       

        // remove top most element

        stk.pop();

   }

   

    return null;

}