My program is supposed to make sure each value the user enters is between 10-100. The value is then stored in the array. That part works fine. The other condition is that the value the user enters has to be different from all the other arrays. ie...array[0]=20 so all of the other arrays can no longer equal to be set to 20. I've been trying to solve this but I'm just not sure where to go. I tried setting statements after my while(userInput < 10 || userInput > 100) to check for any repeats and that worked. The problem was then the user could enter values less than 10 and greater than 100. Any help would be greatly appreciated!
public static void main(String[] args) {
//Creating scanner object
Scanner input = new Scanner(System.in);
int[] array = new int[5];
int counter = 0;
while(counter < 5)
{
for(int x = 0; x < array.length; x++)
{
System.out.print("Enter number between 10 & 100: ");
int userInput = input.nextInt();
while(userInput < 10 || userInput > 100)
{
System.out.print("Please enter number between 10 & 100: ");
userInput = input.nextInt();
}
array[x] = userInput;
System.out.println(array[x]);
counter++;
}
}
System.out.println();
System.out.println("The value of Array[0]: " + array[0]);
System.out.println("The value of Array[1]: " + array[1]);
System.out.println("The value of Array[2]: " + array[2]);
System.out.println("The value of Array[3]: " + array[3]);
System.out.println("The value of Array[4]: " + array[4]);
}
}
You should get rid of the for and second while loop, and check if the value entered is in the desired range.
If it is, you verify for duplicates, store it in the array and increment the counter. If it’s not, you show the bad input message.
Either way, it continues to ask for an valid input until the counter gets to 5.
I hope it helps!
I changed your logic a little bit, see if you can understand it
(There are better ways of doing this, but I think this is more understandable)
public static void main(String[] args) {
//Creating scanner object
Scanner input = new Scanner(System.in);
int[] array = new int[5];
int counter = 0;
while(counter < 5)
{
System.out.print("Enter number between 10 & 100: ");
int userInput = input.nextInt();
if(userInput < 10 || userInput > 100)
{
System.out.print("Please enter number between 10 & 100.\n");
}
else {
//This is a valid input, now we have to check whether it is a duplicate
boolean isItDuplicate = false;
for(int i = 0; i < counter; i++)
{
if(userInput == array[i])
{
isItDuplicate = true;
}
}
if(isItDuplicate == true)
{
System.out.print("Please enter a number that is not a duplicate.\n");
}
else
{
array[counter] = userInput;
System.out.println(array[counter]);
counter++;
}
}
}
System.out.println();
System.out.println("The value of Array[0]: " + array[0]);
System.out.println("The value of Array[1]: " + array[1]);
System.out.println("The value of Array[2]: " + array[2]);
System.out.println("The value of Array[3]: " + array[3]);
System.out.println("The value of Array[4]: " + array[4]);
}
Don't use variable counter when var x does the same thing for you.
Don't use nested loops when the limiting condition of both loops need to be checked together in each iteration. Merge those loops into one wherever possible.
First of all, get rid of your nested loops. They're redundant. Let's look at your problem's specification. Your input needs to fulfill 3 requirements:
Be greater than or equal to 10
Be less than or equal to 100
Be a unique element inside the array
The first two conditions are simple enough to check. For the final condition, you need to search the values inside the array and see if there are any matches to your input. If so, the input is invalid. A simple way to approach this is to check every member of the array and to stop if a duplicate is found. There are better, more efficient ways to do this. Don't be afraid to search the internet to learn a searching algorithm. Below is a simple solution to your problem. It's far from ideal or efficient, but it's easy enough for a beginner to understand.
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int[] array = new int[5];
int counter = 0;
int userInput;
while(counter < 5) {
System.out.print("Enter a number between 10 & 100: ");
userInput = in.nextInt();
if( (userInput >= 10 && userInput <= 100) && !searchDuplicates(array, userInput) ) {
array[counter] = userInput;
counter++;
} else {
System.out.println("Invalid value entered");
}
}
for(int i = 0; i < array.length; i++)
System.out.println("Value " + (i + 1) + ": " + array[i]);
}
private static boolean searchDuplicates(int[] array, int input) {
for(int i = 0; i < array.length; i++)
if(array[i] == input)
return true;
return false;
}
}
Related
The below while loop runs an extra time. I am trying to perform a user input that accepts 10 valid numbers from the user and prints their sum. However, the while loop executes an extra time and asks for the 11th input.
import java.util.Scanner;
class userInput{
public static void main(String[] args) {
int i = 1, sum = 0;
Scanner sc = new Scanner(System.in);
while(i <= 10){
i++;
System.out.println("Enter number " + "#" +i);
boolean isValidNumber = sc.hasNextInt();
if(isValidNumber){
int userChoiceNumber = sc.nextInt();
sum += userChoiceNumber;
}else{
System.out.println("Invalid Input");
}
}
System.out.println("The sum of your entered numbers are = " + sum);
}
}
In addition to those great comments, you should probably only increment "i" if you get a VALID input:
while(i <= 10) {
System.out.print("Enter number " + "#" +i + ": ");
boolean isValidNumber = sc.hasNextInt();
if(isValidNumber){
int userChoiceNumber = sc.nextInt();
sum += userChoiceNumber;
i++;
}else{
System.out.println("Invalid Input");
sc.next();
}
}
Note that when you have a bad input you need to get rid of it with "sc.next()".
First - make sure you're formatted correctly.
(I've indented your loops, moved your output into the main class, fixed up some curly brackets/loop endings).
public static void main(String[] args) {
int i = 1, sum = 0;
Scanner sc = new Scanner(System.in);
while(i <= 10){
i++;
System.out.println("Enter number " + "#" +i);
boolean isValidNumber = sc.hasNextInt();
if(isValidNumber){
int userChoiceNumber = sc.nextInt();
sum += userChoiceNumber;
}
else{
System.out.println("Invalid Input");
}
}
System.out.println("The sum of your entered numbers are = " + sum);
}
Alright - so running the code, I've found there are the correct amount of times asked, but the input prompt is displaying the wrong number with the first input prompt starting on 2, the last one on 11.
The reason for this is the i++ runs before asking for an input, thus it counts up before outputting.
This can easily be fixed by moving said i++ to just underneath the else clause - as follows:
else{
System.out.println("Invalid Input");
}
i++
}
the main problem here is that you're increasing the variable at the start of your while loop. If that's what you're looking for then that's fine, but if you want to stop the loop when it hits 10 you'll need to have it like while(i < 10) if the i++ were at the end of the loop, then you could do while(i <= 10)
Ex:
i = 0;
while(i < 10){
i++;
//code here
}
this will make the code that uses i use the values between 1 and 10. using <= will use the values between 1 and 11.
another example:
i = 0;
while(i < 10){
//code here
i++;
}
this will make the code that uses i use the values between 0 and 9. using <= will use the values between 0 and 10.
another way people do an incremental loop is doing a for loop rather than a while loop
this would look like:
for(int i = 0; i < 10; i++){
//code here
}
this also allows you to create a variable that will only be inside the loop, so rather than making it at the beginning of the method or before the loop, you could make it inside the for loop. This is not good if the variable is used elsewhere though.
I'm working on a project which...
Allows the user to input 4 numbers that are then stored in an array for later use. I also want every time the user decided to continue the program, it creates a new array which can be compared to later to get the highest average, highest, and lowest values.
The code is not done and I know there are some things that still need some work. I just provided the whole code for reference.
I'm just looking for some direction on the arrays part.
*I believe I am supposed to be using a 2-D array but I'm confused on where to start. If I need to explain more please let me know. (I included as many comments in my code just in case.)
I tried converting the inputDigit(); method to accept a 2-D array but can't figure it out.
If this question has been answered before please redirect me to the appropriate link.
Thank you!
package littleproject;
import java.util.InputMismatchException;
import java.util.Scanner;
public class littleProject {
public static void main(String[] args) {
// Scanner designed to take user input
Scanner input = new Scanner(System.in);
// yesOrNo String keeps while loop running
String yesOrNo = "y";
while (yesOrNo.equalsIgnoreCase("y")) {
double[][] arrayStorage = inputDigit(input, "Enter a number: ");
System.out.println();
displayCurrentCycle();
System.out.println();
yesOrNo = askToContinue(input);
System.out.println();
displayAll();
System.out.println();
if (yesOrNo.equalsIgnoreCase("y") || yesOrNo.equalsIgnoreCase("n")) {
System.out.println("You have exited the program."
+ " \nThank you for your time.");
}
}
}
// This method gets doubles and stores then in a 4 spaced array
public static double[][] inputDigit(Scanner input, String prompt) {
// Creates a 4 spaced array
double array[][] = new double[arrayNum][4];
for (int counterWhole = 0; counterWhole < array.length; counterWhole++){
// For loop that stores each input by user
for (int counter = 0; counter < array.length; counter++) {
System.out.print(prompt);
// Try/catch that executes max and min restriction and catches
// a InputMismatchException while returning the array
try {
array[counter] = input.nextDouble();
if (array[counter] <= 1000){
System.out.println("Next...");
} else if (array[counter] >= -100){
System.out.println("Next...");
} else {
System.out.println("Error!\nEnter a number greater or equal to -100 and"
+ "less or equal to 1000.");
}
} catch (InputMismatchException e){
System.out.println("Error! Please enter a digit.");
counter--; // This is designed to backup the counter so the correct variable can be input into the array
input.next();
}
}
}
return array;
}
// This will display the current cycle of numbers and format all the data
// and display it appropriatly
public static void displayCurrentCycle() {
int averageValue = 23; // Filler Variables to make sure code was printing
int highestValue = 23;
int lowestValue = 23;
System.out.println(\n--------------------------------"
+ "\nAverage - " + averageValue
+ "\nHighest - " + highestValue
+ "\nLowest - " + lowestValue);
}
public static void displayAll() {
int fullAverageValue = 12; // Filler Variables to make sure code was printing
int fullHighestValue = 12;
int fullLowestValue = 12;
System.out.println(" RESULTS FOR ALL NUMBER CYCLES"
+ "\n--------------------------------"
+ "\nAverage Value - " + fullAverageValue
+ "\nHighest Value - " + fullHighestValue
+ "\nLowest Value - " + fullLowestValue);
}
// This is a basic askToContinue question for the user to decide
public static String askToContinue(Scanner input) {
boolean loop = true;
String choice;
System.out.print("Continue? (y/n): ");
do {
choice = input.next();
if (choice.equalsIgnoreCase("y") || choice.equalsIgnoreCase("n")) {
System.out.println();
System.out.println("Final results are listed below.");
loop = false;
} else {
System.out.print("Please type 'Y' or 'N': ");
}
} while (loop);
return choice;
}
}
As far as is understood, your program asks the user to input four digits. This process may repeat and you want to have access to all entered numbers. You're just asking how you may store these.
I would store each set of entered numbers as an array of size four.
Each of those arrays is then added to one list of arrays.
A list of arrays in contrast to a two-dimensional array provides the flexibility to dynamically add new arrays.
We store the digits that the user inputs in array of size 4:
public double[] askForFourDigits() {
double[] userInput = new double[4];
for (int i = 0; i < userInput.length; i++) {
userInput[i] = /* ask the user for a digit*/;
}
return userInput;
}
You'll add all each of these arrays to one list of arrays:
public static void main(String[] args) {
// We will add all user inputs (repesented as array of size 4) to this list.
List<double[]> allNumbers = new ArrayList<>();
do {
double[] numbers = askForFourDigits();
allNumbers.add(numbers);
displayCurrentCycle(numbers);
displayAll(allNumbers);
} while(/* hey user, do you want to continue */);
}
You can now use the list to compute statistics for numbers entered during all cycles:
public static void displayAll(List<double[]> allNumbers) {
int maximum = 0;
for (double[] numbers : allNumbers) {
for (double number : numbers) {
maximum = Math.max(maximum, number);
}
}
System.out.println("The greatest ever entered number is " + maximum);
}
i just started learning java and was hoping i could get some help on a logical problem im having. My goal is to as user to enter multiple numbers into an array. I then request the user to insert number from their initial input and print the frequency of that number compared to their first input. I have searched for some time and all the explanations are beyond my level so if anyone could reduce the explanation to a dummy level that will be great.
public class numberCounting {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int[] storage = new int[100];
int counter = 0;
System.out.println("How many total enteries?");
int total = input.nextInt();
for (int i = 1; i <= total; i++) {
System.out.println("Enter the " + i + " number");
int entry = input.nextInt();
storage[i] = entry;
}
System.out.println("what number do you want to count the frequency of?: ");
int frequency = input.nextInt();
for (int x : frequency) {
if (x == x) {
counter++;
}
System.out.println("There are " + counter + "repeats of your number");
}
}
}
You are checking the wrong input and on top of that you are looping wrongly. Does it even compile? Change it to that
for (int x: storage) {
if (x == frequency) counter++;
}
Besides that - an array starts at the zero index. You are skipping the first entry by setting i = 1.
Write a program that reads integers between
1 and 100 and counts the occurrence of each (you should store the numbers in an array). Output should be in ascending order. Assume the input ends when the user enters a 0.
Hi guys, I know that this question has been posted before, perhaps a lot of times, but as I am a complete beginner at java, I don't completely understand the complexity of the codes that are posted. I just started taking Java classes, and would appreciate if you could help me figure out how to get my program to output the correct occurrences at the end. I'm so close to getting the answer but I can't figure it out for the life of me!! Thanks in advance!
import java.util.Scanner;
public class Problem1 {
public static void main(String[] args) {
//declarations
int [] myArray = new int [100];
int input = 5;
Scanner keyboard = new Scanner(System.in);
//input and processing
System.out.println("Please enter integers between 1 and 100 (enter 0 to stop): ");
while (input != 0)
{
input = keyboard.nextInt();
for (int i = 0; i < myArray.length; i++)
{
if (input == i)
{
myArray[i] = input;
}
}
}
//output (This is where I need help!!!!)
for (int k = 0; k < myArray.length; k++)
{
if (myArray[k] != 0)
{
System.out.print(k + " occurs " + myArray[k] + " time");
if (myArray[k] > 1)
{
System.out.println("s");
}
else
System.out.println("");
}
}
keyboard.close();
}
}
You are storing the number entered by the user in the array. Instead, you should store a counter in each position of the array for the corresponding integer. When the user inputs a number, you should increase the corresponding counter.
The second part of your code (output results) seems ok. It is the first one that needs fixing.
I think the first for loop should be something like this:
for (int i = 0; i < myArray.length; i++)
{
if (input == i)
{
myArray[i] += 1;
}
}
}
This should store add 1 to the array everytime the numbers occurs.
hey this my source code that worked out or me.
package test2;
import java.util.Arrays;
import java.util.Scanner;
public class Test2 {
public static void main(String[] args) {
java.util.Scanner input = new java.util.Scanner(System.in);
// ask for user to input numbers
System.out.println("Enter some integers between 1 and 100 (and 0 when done): ");
int[] myArray = new int[1000];//create a new array for user inputs
int number;//variable for user inputs
int count = 0;
do
{
number = input.nextInt();
myArray[count] = number;
count++;
}
while (number != 0);
int[] mySort = new int [count - 1]; //create a new array with only the numbers
for(int i = 0; i< (count-1); i++) { //get the array until 0th number into new
mySort[i] = myArray[i];
}
java.util.Arrays.sort(mySort);// sort the array in ascending order
int n = 0;
for(int i = 0; i < mySort.length; i++) {//check if the number have checked before
int occurance = 0;
if(n >= mySort[i]) {
continue;
}
else {
n = mySort[i];//if a new number found do the calculation+
for (int j=0; j<mySort.length; j++)
if (n == mySort[j])
occurance++;
System.out.print(n + " occurs " + occurance );
{
if (occurance == 1) {
System.out.println(" time.");
}
else {
System.out.println(" times.");
}
}
}
}
}
}
Java code (not Java script). I was asked to create a new integer array with 16 elements.
Only integers between 1 and 7 are to be entered in the array from user (scanner)input.
Only valid user input should be permitted, and any integers entered outside the bounds (i.e. < 1 or > 7 should be excluded and a warning message displayed.
Design a program that will sort the array.
The program should display the contents of the sorted array.
The program should then display the numbers of occurrences of each number chosen by user input
however i have been trying to complete this code step by step and used my knowledge to help me but need help my current code is under I would appreciate if some one is able to edit my code into the above wants.I know it needs to enter the array by user input store and reuse the code to sort the numbers into sort the array.
The result should print out something like this like this
“The numbers entered into the array are:” 1, 2,4,5,7
“The number you chose to search for is” 7
“This occurs” 3 “times in the array”
import java.util.Scanner;
public class test20 {
public static void main (String[] args){
Scanner userInput = new Scanner (System.in);
int [] nums = {1,2,3,4,5,6,7,6,6,2,7,7,1,4,5,6};
int count = 0;
int input = 0;
boolean isNumber = false;
do {
System.out.println ("Enter a number to check in the array");
if (userInput.hasNextInt()){
input = userInput.nextInt();
System.out.println ("The number you chose to search for is " + input);
isNumber = true;
}else {
System.out.println ("Not a proper number");
}
for (int i = 0; i< nums.length; i++){
if (nums [i]==input){
count ++;
}
}
System.out.println("This occurs " + count + " times in the array");
}
while (!(isNumber));
}
private static String count(String string) {
return null;
}
}
import java.util.Scanner;
import java.util.Arrays;
public class test20 {
private static int readNumber(Scanner userInput) {
int nbr;
while (true) {
while(!userInput.hasNextInt()) {
System.out.println("Enter valid integer!");
userInput.next();
}
nbr = userInput.nextInt();
if (nbr >= 1 && nbr <= 7) {
return nbr;
} else {
System.out.println("Enter number in range 1 to 7!");
}
}
}
private static int count(int input, int[] nums) {
int count = 0;
for (int i = 0; i < nums.length; i++){
if (nums[i] == input){
count++;
} else if (nums[i] > input) {
break;
}
}
return count;
}
public static void main(String[] args) {
Scanner userInput = new Scanner(System.in);
int[] nums = new int[16];
for (int i = 0; i < nums.length; i++) {
nums[i] = readNumber(userInput);
}
Arrays.sort(nums);
System.out.println ("Sorted numbers: " + Arrays.toString(nums));
int input = 0;
while(true) {
System.out.println("Search for a number in array");
input = readNumber(userInput);
System.out.println("The number you chose to search for is " + input);
System.out.println("This occurs " +
count(input, nums) + " times in the array");
}
}
}
Because the array is sorted, I break the loop if an element larger than the one we're looking for is found; if we encounter a larger one then no other matches can be found in the rest of the array.