Test plan: either a detailed list of test cases to execute, or a detailed descri
ID: 3812717 • Letter: T
Question
Test plan: either a detailed list of test cases to execute, or a detailed description of your approach to testing your implementation (paragraph form)
DLLNode.JAVA
package ddladt;
public class DLLNode<T>
{
private DLLNode<T> next,back;
private T info;
public DLLNode(T info)
{
this.info = info;
next = null;
}
public void setInfo(T info)
{
this.info = info;
}
public T getInfo()
{
return info;
}
public void setNext(DLLNode<T> next)
{
this.next = next;
}
public DLLNode<T> returnNext()
// Returns next link of this DLLNode.
{
return next;
}
public void setBack(DLLNode<T> back)
{
this.back = back;
}
public DLLNode<T> getBack()
{
return back;
}
}
DLLAdt.JAVA
package ddladt;
public class DLLAdt<T>
{
protected int elemNum;
protected DLLNode<T> current;
protected DLLNode<T> backCurrent;
protected boolean status;
protected DLLNode<T> pos;
protected DLLNode<T> backe;
protected DLLNode<T> dlList;
protected DLLNode<T> end;
//class constructor
public DLLAdt()
{
elemNum = 0;
dlList = null;
end = null;
current = null;
backCurrent = null;
}
//to insert to dd list
public void add(T element)
{
DLLNode<T> newNode = new DLLNode<T>(element);
if(dlList==null)
{
dlList = newNode;
end = dlList;
}
else
{
dlList.setBack(newNode);
newNode.setNext(dlList);
dlList = newNode;
}
elemNum++;
}
protected void find(T target)
{
pos = dlList;
status = false;
while (pos != null)
{
if (pos.getInfo().equals(target))
{
status = true;
return;
}
else
{
backe = pos;
pos = pos.returnNext();
}
}
}
//to get the size
public int size()
{
return elemNum;
}
//to check the presence of an entry
public boolean contains (T element)
{
find(element);
return status;
}
//to delete entries from the list
public boolean delete (T element)
{
find(element);
if (status)
{
if (dlList == pos)
dlList = dlList.returnNext();
else
backe.setNext(pos.returnNext());
elemNum--;
}
return status;
}
public T get(T element)
{
find(element);
if (status)
return pos.getInfo();
else
return null;
}
public String toString()
{
DLLNode<T> currNode = dlList;
String listString = "List: ";
while (currNode != null)
{
listString = listString + " " + currNode.getInfo() + " ";
currNode = currNode.returnNext();
}
return listString;
}
//reset teh list
public void reset()
{
current = dlList;
}
public void backReset()
{
backCurrent = end;
}
public T returnNext()
{
T next = current.getInfo();
if (current.returnNext() == null)
current = dlList;
else
current = current.returnNext();
return next;
}
//get previous
public T getPrevious()
{
T pre = backCurrent.getInfo();
if (backCurrent.getBack() == dlList)
backCurrent = end;
else
backCurrent = backCurrent.getBack();
return pre;
}
}
Test.JAVA
package ddladt;
//The driver program
public class Test
{
public static void main(String args[])
{
DLLAdt<Integer> dlList= new DLLAdt<Integer>();
for(int itr=100;itr>1;itr-=10)
dlList.add(itr);
System.out.println(dlList.toString());
dlList.reset();
dlList.backReset();
System.out.println(" Testing the returnNext() function");
System.out.print(" "+dlList.returnNext().intValue());
System.out.print(" "+dlList.returnNext().intValue());
System.out.print(" "+dlList.returnNext().intValue());
System.out.println(" Testing the getPrevious() function");
System.out.print(" "+dlList.getPrevious().intValue());
System.out.print(" "+dlList.getPrevious().intValue());
System.out.print(" "+dlList.getPrevious().intValue());
}
}
Explanation / Answer
Explanation:
This JAVA program is something like a implememation of user defined Arraylist API.
When we compare the JAVA ArrayList API with our customized JAVA API, The below comparision can be done.
1. List definition
DLLAdt<Integer> dlList = new DLLAdt<Integer>();
Equals to
ArrayList<Integer> integerList = new ArrayList<Integer>();
2. add method implememation
dlList.add();
Equals to
integerList.add()
3. Next element function implememation
dlList.returnNext().intValue()
Equals to
Iterator it=integerList.iterator();
it.hasNext()
4. Previous element function implememation
dlList.getPrevious().intValue()
Equals to
Iterator it=integerList.iterator();
it.hasPrevious();
it.previous();
TestCases:
1. DLLAdt size with zero elements, should be failed at runtime.
-> Step 1 : Update the for loop to below
for (int itr = 0; itr > 1; itr -= 10) {
dlList.add(itr);
}
-> Step 2 : Verify the exception, should be null pointer exception at DLLAdt.java:102
2. DDLADt size shoule be 10 elements as mentione in JAVA program
-> Step 1 : Check the loop should start with 100
for (int itr = 100; itr > 1; itr -= 10) {
dlList.add(itr);
}
-> Step 2 : Out put should print the First three and last three in list.
Expected output :
List: 10 20 30 40 50 60 70 80 90 100
Testing the returnNext() function
10 20 30
Testing the getPrevious() function
100 90 80
3. DDLADt size shoule be more than 10 elements.
-> Step 1 : Check the loop should start with 1000
for (int itr = 1000; itr > 1; itr -= 10) {
dlList.add(itr);
}
-> Step 2 : Out put should print the First three and last three in list.
Expected output :
List: 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200
Testing the returnNext() function
10 20 30
Testing the getPrevious() function
200 190 180