Wednesday 27 July 2016

Chapter 5 Exercise 1, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

*5.1 (Count positive and negative numbers and compute the average of numbers) Write a program that reads an unspecified number of integers, determines how many positive and negative values have been read, and computes the total and average of the input values (not counting zeros). Your program ends with the input 0. Display the average as a floating-point number. Here is a sample run


Enter an integer, the input ends if it is 0: 1 2 -1 3 0
The number of positives is 3
The number of negatives is 1
The total is 5.0
The average is 1.25

Enter an integer, the input ends if it is 0: 0
No numbers are entered except 0

import java.util.Scanner;
 
public class ProgrammingEx5_1 {
 
 public static void main(String[] args) {
  Scanner input = new Scanner(System.in);
  System.out.print("Enter an integer, the input ends if it is 0:");
  int n, countNeg = 0, countPos = 0;
  float sum = 0;
 
  while ((n = input.nextInt()) != 0) {
   sum = sum + n;
 
   if (n > 0) {
    countPos++;
   } else if (n < 0) {
    countNeg++;
   }
 
  }
 
  if (countPos + countNeg == 0) {
   System.out.println("No numbers are entered except 0");
   System.exit(0);
  }
 
  System.out.println("The number of positives is " + countPos);
  System.out.println("The number of negatives is " + countNeg);
  System.out.println("The total is " + sum);
  System.out.println("The average is " + (sum / (countPos + countNeg)));
 
 }
 
}

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