Wildcard Test

//wildcardTest.java

import java.util.ArrayList;

public class WildcardTest

{
public static void main(String[]args)

{
//create, initialize and output ArrayList of Integers, then display total of the elements

Integer[]integers = {1,2,3,4,5};

ArrayListintegerList=new ArrayList();

//insert elements in interger list

for (Integer element:integers)

integerList.add(element);

System.out.printf("integerList contains: %s\n", integerList);

System.out.printf("Total of the elements in integerList:%.0f\n\n", sum(integerList));

//create, initialize and output ArrayList of Doubles, then display total of the elements

Double[]doubles={1.1,3.3,5.5};

ArrayListdoubleList=new ArrayList();

//insert elements in doubleList

for (Double element:doubles)
doubleList.add(element);

System.out.printf("doubleList contains:%s\n", doubleList);

System.out.printf("Total of the elements in doubleList:%.1f\n\n", sum(doubleList));

//create, initialize and output ArrayList of numbers containing both integers and doubles, then display total of the elements

Number[]numbers={1,2.4,3,4.1}; //integers and doubles

ArrayListnumberList=new ArrayList();

//insert elements in numberList

for (Number element:numbers)
numberList.add(element);

System.out.printf("numberList contains:%s\n",numberList);
System.out.printf("Total of the elements in numberList:%.1f\n", sum (numberList));

}//end main

//total the elements; using a wildcard in the ArrayList parameter

public static double sum(ArrayListlist)

{
double total=0; //initialize total

//calculate sum

for (Number element:list)

total +=element.doubleValue();

return total;

}//end method sum
}//end class WildcardTest