1. 7.20 ReverseStrings
Complete the code for the ReverseStrings such that the user can use a stack to store Strings and
then output the Strings in the opposite order from which they were entered. You can ignore the
warning: [unchecked] unchecked cast.
Here is the output from a sample run:
the beginning of a story
is often different than
the end of a story
Reverse is:
the end of a story
is often different than
the beginning of a story
ReverseStrings.java
import java.util.Scanner;
public class ReverseStrings{
public static void main(String[] args){
Scanner keyboard = new Scanner(System.in);
StackInterface<String> stack = new ArrayBasedStack<String>(3);
String line;
for(int i = 1; i <= 3; i++){
//enter you code here to prompt the user for a line of text, save the text, then add to the stack
}
System.out.println("Reverse is:n");
for(int i = 1; i <=3; i++){
//enter the code to print the lines in reverse
}
}//end main
}//end class
ArrayBasedStack.java

2. public class ArrayBasedStack<T> extends Object implements StackInterface<T>{
private int top;
private T [] stack;
public ArrayBasedStack(){
super();
top = -1;
stack = (T[])new Object[10];
}
public ArrayBasedStack(int size){
super();
top = -1;
if(size > 0){
stack = (T[]) new Object[size];
}
else{
stack = (T[]) new Object[10];
}
}
public void push(T item) {
if(top < stack.length - 1) {
top++;
stack[top] = item;
}
}
public void pop() {
if(top >= 0) {
stack[top] = null;
top--;
}
}
public String peek() {
String topItem;
if(top >= 0) {
topItem = stack[top].toString();
}
else {

3. topItem = "The stack is empty";
}
return topItem;
}
}