CODE IN JAVA
2. Exploring Variable Length Parameter Lists
The fileParameters.javacontains a program to test the variable length methodaverage. Note thataveragemust be a static method since it is called from the static methodmain.
1. Compile and run the program.
2. Add a call to find the average of a single integer, say 13. Print the result of the call.
3. Add a call with an empty parameter list and print the result. Is the behavior what you expected?
4. Add an interactive part to the program. Ask the user to enter a sequence of at most 20 nonnegative integers. Your program should have a loop(Use a While loop) that reads the integers into an array and stops when a negative is entered (the negative number should not be stored). Invoke the average method to find the average of the integers in the array (send the array as the parameter). Does this work? If not, then why? Edit your program to fix the problem. Do not modify the original while loop.
5. Add a methodminimumthat takes a variable number of integer parameters and returns the minimum of the parameters. Invoke your method on each of the parameter lists used for the average function.
//*******************************************************
// Parameters.java
//
// Illustrates the concept of a variable parameter list.
//*******************************************************
import java.util.Scanner;
public class Parameters
{
//-----------------------------------------------
// Calls the average and minimum methods with
// different numbers of parameters.
//-----------------------------------------------
public static void main(String[] args)
{
double mean1, mean2;
mean1 = average(42, 69, 37);
mean2 = average(35, 43, 93, 23, 40, 21, 75);
System.out.println ("mean1 = " + mean1);
System.out.println ("mean2 = " + mean2);
}
//----------------------------------------------
// Returns the average of its parameters.
//----------------------------------------------
public static double average (int ... list)
{
double result = 0.0;
if (list.length != 0)
{
int sum = 0;
for (int num: list)
sum += num;
result = (double)sum / list.length;
}
return result;
}
}
Here is a sample of what your output may look like:
mean1 = 49.333333333333336 and min1 = 37
mean2 = 47.142857142857146 and min2 = 21
mean3 = 13.0 and min3 = 13
Return value of average for an empty parameter list is 0.0
Return value of minimum is 2000000000
Enter a sequence of at most 20 non-negative integers with a negative to signal the end....
22
44
66
-1
The average of the array elements is 6.6
The minimum is 0
Average of numbers read in is 44.0
Minimum of numbers read in is 22