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Java average program with any number of inputs

What I'm trying to make is an averaging program that takes any number of inputs. So far I need to have the user specify how many numbers they want to average, and if they don't give that many numbers the program crashes. Is there any way that I could just have them put as many numbers as they want and afterwards the array length is set?
Here is the code I am using right now:
import java.util.*;
public class Average_any
{
public static void main (String[] args) {
Scanner scan = new Scanner (System.in);
System.out.println ("How many numbers do you want to enter?");
final int ARRAY_LENGTH = scan.nextInt();
System.out.println ("Please type the numbers you want to find the average of, "
+ "and then type \"Done\".");
System.out.println ("Warning: Only type the exact amount of numbers that you specified.");
// If user doesn't enter same number, results in crash
double[] numbers = new double [ARRAY_LENGTH];
do {
for (int i = 0; i < numbers.length; i++) {
while (!scan.hasNextInt()) {
System.out.println("That's not a number!");
scan.next(); //Need this to enter another input
}
numbers[i] = scan.nextInt();
}
} while (!scan.hasNext("Done"));
double total = 0;
for (int i = 0; i < numbers.length; i++) {
total += numbers[i];
}
double average = total/ARRAY_LENGTH;
System.out.println ("Your average is: " + average);
}
}
(Just in case anyone is wondering, no this is not a school assignment, I was just wondering because we did a simpler version in school)

Take the array out of the equation altogether
Scanner scan = new Scanner (System.in);
double total = 0;
int count = 0;
while (scan.hasNextDouble()) {
total += scan.nextDouble();
count ++;
}
double average = total / count;

Prompt and input numbers and calculate sum, difference, and product

The assignment is to "write a Java program to prompt for and input three numbers. Output the sum of the largest two numbers. Output the difference of the largest and smallest number. Output the product of the smallest two numbers."
I've written the code out but it's not calculating properly. I've included my code below so please feel free to take a look and critique as needed.
import java.util.Scanner;
public class Homework4a {
public static void main (String[] args) {
//Declare Scanner object and three numbers (ints) and ints for smallest and largest numbers
Scanner keyboard;
int firstUsernumber;
int secondUsernumber;
int thirdUsernumber;
int largestnumber;
int smallestnumber;
int largestnumber2;
int smallestnumber2;
int largestnumber3;
int smallestnumber3;
//Instantiate keyboard
keyboard = new Scanner(System.in);
//Prompt the user for input
System.out.print("Enter your first number here: ");
//Obtain and store first number
firstUsernumber = keyboard.nextInt();
//Prompt the user for second input
System.out.print("Enter your second number here: ");
//Obtain and store the second input
secondUsernumber = keyboard.nextInt();
//Prompt the user for third input
System.out.print("Enter your third number here: ");
//Obtain and store the second input
thirdUsernumber = keyboard.nextInt();
//Determine largest number
if (firstUsernumber > secondUsernumber) {
largestnumber = firstUsernumber;
smallestnumber = secondUsernumber;
} else {
largestnumber = secondUsernumber;
smallestnumber = firstUsernumber;}
if (secondUsernumber > thirdUsernumber) {
largestnumber2 = secondUsernumber;
smallestnumber2 = thirdUsernumber;
} else {
largestnumber2 = thirdUsernumber;
smallestnumber2 = secondUsernumber;}
if (firstUsernumber > thirdUsernumber) {
largestnumber3 = firstUsernumber;
smallestnumber3 = thirdUsernumber;
} else {
largestnumber3 = thirdUsernumber;
smallestnumber3 = firstUsernumber;
}//Ending bracket of if statement
//Calculate sum of largest numbers
System.out.println("The sum of the largest numbers is: " + (largestnumber + largestnumber2));
//Calculate the difference of the largest and smallest number
System.out.println("The difference of the largest number and smallest number is: " + (largestnumber - smallestnumber));
//Calculate the product of the smallest numbers
System.out.println("The product of the smallest numbers is: " + (smallestnumber*smallestnumber3));
}//Ending bracket method main
}//Ending bracket class Homework4a

import java.util.Scanner;
//this program takes three integers from the user and outputs the sum of the largest two numbers, the difference of the largest and smallest number, and the product of the smallest two numbers.
// done by Nadim Baraky
public class OperationsOnNumbers {
public static void main(String[] args) {
//declare three integer variables
int firstMax, secondMax, min;
//firstMax: largest number; secondMax: the number in between; min: the smallest number.
Scanner input = new Scanner(System.in);
System.out.print("Enter your first number: ");
int firstNumber = input.nextInt();
System.out.print("Enter your second number: ");
int secondNumber = input.nextInt();
System.out.print("Enter your third number: ");
int thirdNumber = input.nextInt();
input.close();
firstMax = Math.max(Math.max(firstNumber, secondNumber),thirdNumber);
if(firstMax == firstNumber) {
secondMax = Math.max(secondNumber, thirdNumber);
}
else if(firstMax == secondNumber) {
secondMax = Math.max(firstNumber, thirdNumber);
}
else {
secondMax = Math.max(firstNumber, secondNumber);
}
min = Math.min(Math.min(firstNumber, secondNumber), thirdNumber);
System.out.println("The sum of the largest two numbers is: " + (firstMax + secondMax));
System.out.println("The difference of the largest and smallest numbers is: " + (firstMax - min));
System.out.println("The product of the smallest two numbers: " + secondMax * min);
}
}

populating the array with the user input

i apologize i know this looks simple but i'm kinda new to coding. the goal of the program is to take inputs from the user starting at index 0 and then save the inputs into the array. i'm probably close to solving this but i need some help.
here is the code:
public class ArrayTest
{
public static void main(String [] args)
{
Scanner input = new Scanner(System.in);
int numberOfGrades;
int counter = 0;
System.out.println("This program averages the grades you input.");
System.out.println("Please enter the number of grades you'd like averaged: ");
numberOfGrades = input.nextInt();
int[] grades = new int[numberOfGrades];
do
{
System.out.println("Please enter grade number " + (counter+1) + ": ");
grades[numberOfGrades] = input.nextInt();
counter++;
} while (counter < numberOfGrades);
System.out.println("The number of grades you wanted averaged was: " + grades.length);
}
}

Your logic is a bit off. numberOfGrades is the.. well.. number of grades. And when you do this: grades[numberOfGrades] = input.nextInt(); then you put the user's input in the grades array in location numberOfGrades, which you don't want.
What you do want is:
do {
System.out.println("Please enter grade number " + (counter+1) + ": ");
grades[counter] = input.nextInt();
counter++;
} while (counter < numberOfGrades);
This way, the array in location counter is accessed, and the user's input is placed inside it in the correct location.
Also, to calculate the average of the grades, like you are trying to do in the end of your program, you should do:
double sum = 0;
for (int grade : grades)
sum += grade;
And then your average will be:
average = 1.0d * sum / grades.length;
You can just as well put this summing logic inside your do-while loop and avoid the extra loop I introduced.

this instruction
grades[numberOfGrades] = input.nextInt();
must be replaced by
grades[counter] = input.nextInt();

try this ...
The thing that you were doing wrong is in the do while loop you were inserting value in the same array index grades[numberOfGrades] = input.nextInt(); should be replaced by grades[counter] = input.nextInt();
public class ArrayTest
{
public static void main(String [] args)
{
Scanner input = new Scanner(System.in);
int numberOfGrades;
int counter = 0;
System.out.println("This program averages the grades you input.");
System.out.println("Please enter the number of grades you'd like averaged: ");
numberOfGrades = input.nextInt();
int[] grades = new int[numberOfGrades];
do
{
System.out.println("Please enter grade number " + (counter+1) + ": ");
grades[counter] = input.nextInt();
counter++;
} while (counter < numberOfGrades);
System.out.println("The number of grades you wanted averaged was: " + grades.length);
}
}

You can try like this
public class ArrayTest {
public static void main(String[] args) {
Scanner input=new Scanner(System.in);
System.out.println("enter number of elements");
int n=input.nextInt();
int arr[]=new int[n];
System.out.println("enter elements");
for(int i=0;i<n;i++){//for reading array
arr[i]=input.nextInt();
}
for(int i: arr){ //for printing array
System.out.println(i);
}
}

Loop not quite working java

I am new to stackoverflow. First I would like the program to loop with a price, then a question(enter another price?), price, then a question and so on. Below is the output.
Please enter a price:
33
Enter another price?
y
Please enter a price:
66
Please enter a price:
99
Please enter a price:
22
However it will keep looping at the end with "Please enter a price:". I want it to do:
Please enter a price:
33
Enter another price?
y
Please enter a price:
66
Enter another price?
y
Please enter a price:
22
Can anyone help me with this? Also, sometimes the average does not update fully. Thanks :)
import java.util.Scanner;
public class ReadInPrice {
public static void main(String[] args) {
int integer = 0;
int count = 0;
double sum = 0;
double average = 0;
Scanner input = new Scanner(System.in);
String addPrice;
System.out.println("Please enter a price: ");
integer = input.nextInt();
do {
System.out.println("Enter another price? ");
addPrice = input.next();
while (addPrice.equalsIgnoreCase("Y")) { // change this line to while user response = no etc may need a enter another number?
count = count + 1;
sum = sum + integer;
System.out.println("Please enter a price: ");
integer = input.nextInt();
}
}
while (addPrice.equalsIgnoreCase("Y"));
average = sum / count;
System.out.println("Average = " + average);
input.close();
}
}

You need to replace your while with an if
if (addPrice.equalsIgnoreCase("Y")) { // change this line to while user response = no etc may need a enter another number?
count = count + 1;
sum = sum + integer;
System.out.println("Please enter a price: ");
integer = input.nextInt();
}
In fact, addPrice is not modified within your second while loop, and so you have an infinite loop.
In order to do the averaged price, you're in the right way but not in the right place :P
count = count +1 and sum = sum + integer should be done after each integer = input.nextInt(). In your current code, you don't increment the counter and don't add the integer for the last input.
System.out.println("Please enter a price: ");
integer = input.nextInt();
count++ ; // count = count +1
sum += integer ; // sum = sum + integer
do {
System.out.println("Enter another price? ");
addPrice = input.next();
while (addPrice.equalsIgnoreCase("Y")) { // change this line to while user response = no etc may need a enter another number?
System.out.println("Please enter a price: ");
integer = input.nextInt();
count++ ; // count = count +1
sum += integer ; // sum = sum + integer
}
}
while (addPrice.equalsIgnoreCase("Y"));
Finally here is a improved version which avoid the use of if.
int sum = 0;
int integer = 0;
String addPrice = "Y";
while( "Y".equalsIgnoreCase(addPrice) ) {
System.out.println("Please enter a price: ");
integer = input.next();
sum += integer ;
count++;
System.out.println("Enter another price? ");
addPrice = input.next();
}
int avg = sum / count ;

What you should do is change your logic a bit. You need to repeat two actions, entering a price and asking if the user wants to enter another price. Only one loop is required for this.
do {
System.out.println("Please enter a price: ");
integer = input.nextInt();
count = count + 1;
sum = sum + integer;
System.out.println("Enter another price? ");
addPrice = input.next();
} while (addPrice.equalsIgnoreCase("Y"));

i think you want something like this:
import java.util.Scanner;
public class ReadInPrice {
public static void main(String[] args) {
int integer = 0;
int count = 0;
double sum = 0;
double average = 0;
Scanner input = new Scanner(System.in);
String addPrice = "Y";
while (addPrice.equalsIgnoreCase("Y")){
System.out.println("Please enter a price: ");
integer = input.nextInt();
count++;
sum += integer;
System.out.println("Enter another price? ");
addPrice = input.next();
}
average = sum / count;
System.out.println("Average = " + average);
input.close();
}
}

Try this:
EDIT Added min and max.
public class ReadInPrice {
public static void main(String[] args) {
//better to use 2 scanners when dealing with both string and int
//one for string ; one for ints
Scanner strScanner = new Scanner(System.in);
Scanner intScanner = new Scanner(System.in);
boolean enter = true;
int sum = 0;
int count = 0;
int min=Integer.MAX_VALUE;
int max=0;
while (enter) { //while user wants to keep adding numbers
System.out.println("Please enter a price: ");
int price = intScanner.nextInt();
if(price < min)
min=price;
if(price > max)
max=price;
sum += price;
count++;
System.out.println("Enter another price? ");
String answer = strScanner.nextLine();
if (!answer.equalsIgnoreCase("Y"))
enter = false; //user doesn't want to keep adding numbers - exit while loop
}
double average = (double)sum / count;
System.out.println("Average = " + average);
System.out.println("Min = " + min);
System.out.println("Max = " + max);
strScanner.close();
intScanner.close();
System.exit(0);
}
}

Using the while loop to ask user their input in JAVA

I have like 3 hours trying to solve this simple problem. Here is what I am trying to accomplished: Ask the user to enter a number, and then add those numbers. If the users enters five numbers, then I should add five numbers.
Any help will be appreciated.
import java.util.Scanner;
public class loopingnumbersusingwhile
{
public static void main(String args[])
{
Scanner kb = new Scanner(System.in);
int input;
System.out.println("How Many Numbers You Want To Enter");
total = kb.nextInt();
while(input <= kb.nextInt())
{
input++;
System.out.println("How Many Numbers You Want To Enter" + input);
int input = kb.nextInt();
}
}
}

Your current code is trying to use input for too many purposes: The current number entered, the amount of numbers of entered, and is also trying to use total as both the sum of all numbers entered and the amount of numbers to be entered.
You'll want 4 separate variables to track these 4 separate values: how many numbers the user will entered, how many they entered so far, the current number they entered, and the total.
int total = 0; // The sum of all the numbers
System.out.println("How Many Numbers You Want To Enter");
int count = kb.nextInt(); // The amount of numbers that will be entered
for(int entered = 0; entered < count; total++)
{
int input = kb.nextInt(); // the current number inputted
total += input; // add that number to the sum
}
System.out.println("Total: " + total); // print out the sum

Add this code after you take how many numbers the user wants to add:
int total;
for(int i = 0; i < input; i--)
{
System.out.println("Type number: " + i);
int input = kb.nextInt();
total += input;
}
To print this just say:
System.out.println(total);

import java.util.Scanner;
public class LoopingNumbersUsingWhile
{
public static void main(String args[])
{
Scanner kb = new Scanner(System.in);
int input=0;
int total = 0;
System.out.println("How Many Numbers You Want To Enter");
int totalNumberOfInputs = kb.nextInt();
while(input < totalNumberOfInputs)
{
input++;
total += kb.nextInt();
}
System.out.println("Total: " +total);
}
}

You seem to be asking how many numbers twice.
public static void main(String args[])
{
Scanner kb = new Scanner(System.in);
System.out.println("How Many Numbers You Want To Enter");
int howMany = kb.nextInt();
int total = 0;
for (int i=1; i<=howMany; i++) {
System.out.println("Enter a number:");
total += kb.nextInt();
}
System.out.println("And the grand total is "+total);
}

What you should pay attention to:
name classes in CamelCase starting with a big letter
initialize total
don't initialize input twice
show an appropriate operand input request to your user
take care of your loop condition
don't use one variable for different purposes
which variable should hold your result?
how to do the actual calculation
Possible solution:
import java.util.Scanner;
public class LoopingNumbersUsingWhile {
public static void main(String args[]) {
Scanner kb = new Scanner(System.in);
System.out.println("How Many Numbers You Want To Enter: ");
int total = kb.nextInt();
int input = 0;
int sum = 0;
while (input < total) {
input++;
System.out.println("Enter " + input + ". Operand: ");
sum += kb.nextInt();
}
System.out.println("The sum is " + sum + ".");
}
}