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Java User Input array is only capturing 3 integers instead of five

This code is supposed to capture 5 user integers, print them out, then print them in reverse. It is capturing the first int only, and printing it 3 times, then printing the first integer again 5 more times without reversing. Test ends with "Process finished with exit code 0" which I think is says the program finished without errors -- which of course is not correct. I assume the issue is in how the user input array is stored. I have it assigning as userNum[i] with a limited array of 5, and int i =0 to begin array storage at userNum[0], so I'm not clear on why all the inputs are not captured up to userNum[4].
Thank you for any insight you can provide. I am very new to java and this is prework for my java class.
import java.util.Scanner;
public class ArrayReverse {
public static void main(String[] args) {
Scanner scnr = new Scanner(System.in); // scanner for input
final int NUM_VALS = 5; // number on int user able to enter
int[] userNum = new int[NUM_VALS]; // user integers storage
int j = 0;
int i = 0;
System.out.println("Enter integer values: ");
userNum[i] = scnr.nextInt(); // capture user input int
for (j = 0; j < NUM_VALS; j++) {
System.out.print("You entered: ");
System.out.println(userNum[i]);
++j;
}
System.out.print("\nNumbers in reverse: "); // statement to Print reversed array
for (j = NUM_VALS - 1; j >= 0; j--) {
System.out.print(userNum[i] + " ");
}
}
}

You need to work more about on for loops and study how to iterate values in for loop, the problem in your i,j variables.
Here I fix your code.
import java.util.Scanner;
public class ArrayReverse {
public static void main(String[] args) {
Scanner scnr = new Scanner(System.in); // scanner for input
final int NUM_VALS = 5; // number on int user able to enter
int[] userNum = new int[NUM_VALS]; // user integers storage
int j = 0;
int i = 0;
//for 5 inputs you need loop
for(;i<NUM_VALS;i++){
System.out.println("Enter integer values: ");
userNum[i] = scnr.nextInt(); // capture user input int
}
for (j = 0; j < NUM_VALS; j++) {
System.out.print("You entered: ");
System.out.println(userNum[j]);
//++j; //no need to increment as you already did in for loop
}
System.out.print("\nNumbers in reverse: "); // statement to Print reversed array
for (j = NUM_VALS - 1; j >= 0; j--) {
System.out.print(userNum[j] + " ");// userNum[0] = your last value which you reverse
}
}
}

Here is a solution using the collections framework:
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
public class ArrayReverse {
public static void main(String[] args) {
Scanner scnr = new Scanner(System.in); // scanner for input
final List<Integer> numbers = new ArrayList<>();
System.out.println("Enter any number of integers. (whitespace delimited. enter a non-integer to quit.): ");
while (scnr.hasNextBigInteger()) {
final int n = scnr.nextInt();
System.out.println("Parsed: " + n);
numbers.add(n);
}
System.out.println("Done reading user input.");
System.out.println("Your input: " + numbers);
Collections.reverse(numbers);
System.out.println("Your input reversed: " + numbers);
}
}

I have provided you with a solution. This is a clean way of doing it.
nextInt() reads the next integer that the user inputs. Notice that this will throw a InputMismatchExceptionif the user does not input a integer as value.
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
List<Integer> input = new ArrayList<Integer>();
//Simple loop that will read 5 user inputs
//and add them to the input list
for(int i = 0; i < 5; i++){
input.add(scanner.nextInt());
}
//print the 5 values
for(Integer val : input){
System.out.println(val);
}
//reverse the 5 values
Collections.reverse(input);
//print the 5 values again, but they are now reversed
for(Integer val : input){
System.out.println(val);
}
}

Creating a java program that takes user input for an array and then using my own number and multiplying it by each day

Essentially, I am asking the user for an input of how manys days they would like something to happen (array). Once the user inputs that amount, I must make it to where it will display the number 1 for the first number they inputed and then have a set way of multipying each number after by 2. What I am having a hard time understanding is how I can correlate the user input array to the exact amount of the array I am going to create. My code so far.
Scanner keyboard = new Scanner(System.in);
int num = keyboard.nextInt();
int[] daysOfRice = new int[num];
for (int i = 0; i < daysOfRice.length; i++) {
System.out.println(daysOfRice);
}
System.out.print(daysOfRice);

I am not sure what exactly is your requirement, have a look:
public class TestC {
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
int num = keyboard.nextInt();
keyboard.close();
int[] daysOfRice = new int[num];
int prod = 1;
for (int i = 1; i <= daysOfRice.length; i++) {
if (i == 1) {
prod = 1;
} else {
prod = prod * 2;
}
System.out.println("Day " + i + ": " + prod
+ " grains of rice are given");
}
}
}

How can the numbers in array count to odd or even number?

I wrote the code in java but it does not count to odd or even. It only counts in even numbers. If I miss anything?
import java.util.Scanner;
public class OddEven {
//create the check() method here
static void check(int[] x, int n) {
x = new int[100];
Scanner in = new Scanner(System.in);
while (in.hasNextInt()) {
x[n++] = in.nextInt();
}
if (x[n] % 2 == 0) {
System.out.println("You input " + n + " Even value");
} else if (x[n] % 2 == 1) {
System.out.println("You input " + n + " Odd value");
}
while (in.hasNextInt()) ;
}
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
//read the data here
System.out.print("Input a list of Integer number : ");
int[] x = new int[100];
int n = 0;
check(x, n);
in.close();
}
}

Check these loops:
This essentially puts all the ints in x.
while(in.hasNextInt()) {
x[n++] = in.nextInt();
}
This just loops until it doesn't have an it.
while(in.hasNextInt());
Which means, the if block is not even in a loop. However, the first while loop post increments n, which means even if you have one number, it will assign:
x[0] = 123;
but then n=1. which means, the if block will check the next field. But by default it is 0, which will display that it is even.
This would make more sense:
x= new int[100];
Scanner in = new Scanner(System.in);
while(in.hasNextInt()) {
x[n] = in.nextInt();
if(x[n]%2==0){
System.out.println("You input "+n+" Even value");
}else if(x[n]%2==1){
System.out.println("You input "+n+" Odd value");
}
n++;
}

Counting occurrences of integers in an array program java

I am trying to find the occurrences of all integers submitted by the user into the program and so far here's what I got. It works but I don't think it's a legit way to do it, is there any way I can try to do this without using the list[10]=9999;? Because if I don't do it, it'll show out of boundary error.
import java.util.*;
public class OccurrencesCount
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
int[] list = new int[11];
//Accepting input.
System.out.print("Enter 10 integers between 1 and 100: ");
for(int i = 0;i<10;i++){
list[i] = scan.nextInt();
list[10] = 9999;
}
//Sort out the array.
Arrays.sort(list);
int count = 1;
for(int i = 1;i<11;i++){
if(list[i-1]==list[i]){
count++;
}
else{
if(count<=1){
System.out.println(list[i-1] + " occurs 1 time.");
}
else{
System.out.println(list[i-1] + " occurrs " + count + " times.");
count = 1;
}
}
}
}
}

Personally, I think this is a perfectly good solution. It means that you can deal with the last group in the same way as all others. The only change I would make is putting the line list[10] = 9999; outside the for loop (there's no reason to do it 10 times).
However, if you want to use an array of length 10, you can change the line
if(list[i-1]==list[i])
to
if(i < 10 && list[i-1]==list[i])
If you do this, you won't get an ArrayIndexOutOfBoundsException from list[i] because the expression after the && is not evaluated when i == 10.

import java.util.*;
class OccurrencesCount {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int[] list = new int[101];
System.out.print("Enter 10 integers between 1 and 100: ");
for(int i = 0;i<10;i++) {
int x = scan.nextInt();
list[x]++;
}
for(int i = 1; i <= 100; i++)
if(list[i] != 0)
System.out.println(i + " occurs " + list[i] + " times ");
}
}
To store count of numbers from 1 to 100 you need to use a list of 100 integers each one storing the number of occurrences of itself. Better approach would be to use a Map.

I have made use of ArrayList and Collections package instead of regular arrays as a different flavor if it interests you check it out.
import java.util.*;
public class OccurrencesCount {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
List<Integer> list = new ArrayList<>();
//Accepting input.
System.out.print("Enter 10 integers between 1 and 100: ");
for (int i = 0; i < 10; i++) {
list.add(scan.nextInt());
}
Collections.sort(list);
Integer prevNumber = null;
for (int number : list) {
if (prevNumber == null || prevNumber != number) {
int count = Collections.frequency(list, number);
System.out.println(number + " occurs " + count + (count > 1 ? " times." : " time."));
}
prevNumber = number;
}
}
}

I got it figured out guys, only changed a couple of small things inside the conditions and everything went smoothly! Thanks for the help! Now I just need to find a way to restrict the inputs from going above 100.
import java.util.*;
public class CountOccurrences
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
int[] list = new int[10];
//Accepting input.
System.out.print("Enter 10 integers between 1 and 100: ");
for(int i = 0;i<=9;i++){
list[i] = scan.nextInt();
}
//Sort out the array.
Arrays.sort(list);
int count = 1;
for(int i = 1;i<=10;i++){
if(i<=9 && list[i-1]==list[i]){
count++;
}
else{
if(count<=1){
System.out.println(list[i-1] + " occurs 1 time.");
}
else{
System.out.println(list[i-1] + " occurrs " + count + " times.");
count = 1;
}
}
}
}
}

Loop to validate user input

I am fairly new to Java and I am trying to write a small program that asks a user to enter 3 integers between 1-10, stores them in an array and then adds up the integers and tells the user the answer. I have written this so far and it works:
import java.util.Scanner;
public class Feb11a {
public static void main(String[] args) {
int[] numArr = new int[3];
int sum = 0;
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter 3 numbers in the range 1 to 10: ");
for (int i = 0; i < numArr.length; i++) {
numArr[i] = keyboard.nextInt();
}
for (int counter = 0; counter < numArr.length; counter++) {
sum += numArr[counter];
}
System.out.println("The sum of these numbers is " + sum);
}
}
My problem is I am also meant to validate the input as in if they enter a double, a string or a number outside the 1-10 range. I have tried a while loop but I just cannot get the program to work, below is what I have so far. If I take out the first while loop the second one works i.e. it checks if it is an integer:
import java.util.Scanner;
public class Feb11a {
public static void main(String[] args) {
int[] numArr = new int[3];
int sum = 0;
Scanner keyboard = new Scanner(System.in);
for (int i = 0; i < numArr.length; i++) {
//check if between 1 and 10
while (i > 10 || i < 1) {
System.out.println("Enter a number in the range 1 to 10: ");
//check if integer
while (!keyboard.hasNextInt()) {
System.out.println("Invalid entry, please try again ");
keyboard.next();
}
numArr[i] = keyboard.nextInt();
}
}
for (int counter = 0; counter < numArr.length; counter++) {
sum += numArr[counter];
}
System.out.println("The sum of these numbers is " + sum);
}
}
My question is how do I get it to check if it is an integer and if it is the range 1-10?

import java.util.Scanner;
public class NewClass {
public static void main(String[] args)
{
int[] numArr = new int[3];
int sum=0,x;
Scanner keyboard = new Scanner(System.in);
for(int i=0; i<numArr.length; i++)
{
//check if between 1 and 10
System.out.println("Enter a number in the range 1 to 10: ");
//check if integer
while (!keyboard.hasNextInt())
{
System.out.println("Invalid entry, please try again ");
keyboard.next();
}
x = keyboard.nextInt();
if(x>0 && x<=10)
numArr[i]=x;
else{
System.out.println("Retry Enter a number in the range 1 to 10:");
i--;
}
}
for (int counter=0; counter<numArr.length; counter++)
{
sum+=numArr[counter];
}
System.out.println("The sum of these numbers is "+sum);
}
}

To check simple use Integer.parseInt() and catch the NumberFormatException (together with Scanner.next()).
Once format is correct you can do an int comparison (i>0 && i<11).

I suggest you to use NumberUtils under org.apache.commons.lang.math
It has isDigits method to check whether given string contains only digits or not:
if (NumberUtils.isDigits(str) && NumberUtils.toInt(str) < 10) {
// your requirement
}
Note that toInt returns zero for big numbers!
Maybe for just this reason adding a whole library seems unnecessary but for bigger projects you will need such libraries like Apache Commons and Guava

You can wrap the System in into a BufferedReader to read whatever the user has to input, then check if its an 'int' and repeat input from user.
I have modified your code a little bit to make it work.
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
public class Feb11a {
public static void main(String[] args) throws NumberFormatException, IOException
// You may want to handle the Exceptions when calling the getInt function
{
Feb11a tester = new Feb11a();
tester.perform();
}
public void perform() throws NumberFormatException, IOException
{
int[] numArr = new int[3];
int sum = 0;
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
for (int i = 0; i < numArr.length; i++)
{
int anInteger = -1;
do
{
// First get input from user.
System.out.println("Enter a number in the range 1 to 10: ");
anInteger = getInt(in);
} while (anInteger > 10 || anInteger < 1); // then check for repeat condition. Not between 1 and 10.
numArr[i] = anInteger; // set the number into the array.
}
for (int counter = 0; counter < numArr.length; counter++)
{
sum += numArr[counter];
}
System.out.println("The sum of these numbers is " + sum);
}
public int getInt(BufferedReader br) throws NumberFormatException, IOException
{
String str = br.readLine();
int toReturn = Integer.parseInt(str);
return toReturn;
}
}