I have a program here in java that asks the user to input ten integer numbers and would print out how many are ODD and how many are EVEN.
import java.io.*;
public class Count {
public static void main(String[] args) {
int i, , even_ctr=0, odd_ctr = 0;
String input = " ";
BufferedReader in = new BufferedReader ( new InputStreamReader(System.in));
for(i = 1; i <=10; i++){
try{
System.out.print("Input integer number: ");
input = in.readLine();
}catch(IOException e){
System.out.println("Error!");
}
n = Integer.parseInt(input);
if(n % 2 == 0)
even_ctr++; //counter for even
if(n % 2 == 0)
odd_ctr++; //counter for odd
}System.out.println("EVEN: " + even_ctr + "\nODD: "+ odd_ctr);
}
}
I am trying to change the program by using only one counter instead of two counter. Anyone knows how?
import java.io.*;
public class NewClass {
public static void main(String[] args) {
int i,n, even_ctr=0;
String input = " ";
BufferedReader in = new BufferedReader ( new InputStreamReader(System.in));
for(i = 1; i <=10; i++){
try{
System.out.print("Input integer number: ");
input = in.readLine();
}catch(IOException e){
System.out.println("Error!");
}
n = Integer.parseInt(input);
if(n % 2 == 0)
even_ctr++;
}System.out.println("EVEN: " + even_ctr + "\nODD: "+ (10-even_ctr));
}
}
Just keep the first counter incrementing for ODD number detection (OR EVEN but either of them). At the end of the computation, if ODD counter = 4, and total number of numbers entered are 10, then 10 - ODDcounter = 10 - 4 = 6 are the number of even numbers.
For this it looks like it would be equally useful to use the Scanner so that you can avoid the step of having to parse the string.This also would require you to import java.util.Scanner but you can use the scanner to take in strings or integers.
Scanner in = new Scanner(System.in);
int input;
int evenCount = 0;
for(i = 1; i <=10; i++){
try{
System.out.print("Input integer number: ");
input = in.nextInt();
}catch(IOException e){
System.out.println("Error!");
}
if(input % 2 == 0)
evenCount++;
}
System.out.println("EVEN: " + evenCounter + "\nODD: "+ (10 - evenCounter);
Include in.close(); at the end of the method to close the scanner or the reader which ever you use.
package evenoddten;
import java.util.Scanner;
public class EvenOddTen {
public static void main(String[] args) {
int num1 = 0, num2, even = 0, count = 0;
Scanner scr = new Scanner(System.in);
System.out.print("Total Nos:");
num2 = scr.nextInt();
while(count<num2) {
System.out.println("Enter no:");
num1 = scr.nextInt();
if (num1%2 == 0) {
even = even + 1;
}
count = count+1;
}
System.out.println("Even nos are:"+even);
System.out.println("Odd nos are:"+(count - even));
}
}
Related
My code won't allow me to enter in multiple integers to where it can then compute the sum, the count of integers, the minimum, and the sum of positive even integers. I am not sure if I need another method or if im calling for the wrong things.
import java.util.Scanner;
public class Assignment2 {
private static final Scanner input = null;
private static int n;
public static void main(String[] args){
Scanner scan = new Scanner(System.in);
int sum=0, minNumber=0, nCount=0, countEvenIntegers=0;
Scanner sc = new Scanner(System.in);
int i = sc.nextInt();
//when code reads 0, code terminates
int[] numbers = new int[4];
for(int i=0; i<4; i++){
numbers[i] =sc.nextInt();
}
while(!(n==0)){
sum += n;
n = input.nextInt();
}
class SumOfValues {
public int sum(int...vals){
int sum=0;
for (int val : vals) {
sum+= val;
}
return sum;
}
}
class CountingInts{
public void main(String[] args){
Scanner input=new Scanner(System.in);
int count=0;
System.out.print("Numbers: ");
while (input.hasNextInt()){
input.nextInt();
count++;
}
System.out.print(count);
input.close();
}
}
int sumPositive = 0;
System.out.println("The minimum integer is " + minNumber + "\nThe count of integers is "
+ nCount + "\nThe sum of positive integers is " + sumPositive + "\nThe count of even integers in the sequence is " +
countEvenIntegers );
}
}
It looks like you are an absolute beginner, so I'd recommend not dealing with functions and classes and all that, and just write everything linearly. I'm not sure why you have all those functions, classes and variables, but to help you, this is probably the simplest way to achieve what you are trying to do.
import java.util.Scanner;
public class Assignment2 {
public static void main(String[] args) {
int sum = 0, minNumber = 0, nCount = 0, countEvenIntegers = 0;
Scanner sc = new Scanner(System.in);
while (true) {
int input = sc.nextInt();
if (input == 0) {
break;
}
sum += input;
nCount += 1;
}
System.out.println("The minimum integer is " + minNumber);
System.out.println("The count of integers is " + nCount);
System.out.println("The sum of positive integers is " + sum);
System.out.println("The count of even integers in the sequence is " + countEvenIntegers);
}
}
Note that I've not added the minimum interger and count of even intergers for you to complete.
Not quite sure what you are doing in your code since you are not doing any operations on the variables you are outputting, and thus should not expect the output to be any other than 0.
Also, your inner classes are really weird.
Here is an example (based on your code) that does what you want. Plenty of ways of achieving your goal, but I think this is simple enough:
import java.util.Scanner;
import java.util.*;
public class Assignment2{
private static final Scanner input = null;
private static int n;
public static void main(String[] args){
Scanner scan = new Scanner(System.in);
int sum=0, minNumber=0, nCount=0, countEvenIntegers=0, sumPositive = 0;
Scanner sc = new Scanner(System.in);
List<Integer> numbers = new ArrayList<Integer>();
while(true) {
int i = sc.nextInt();
if(i == 0) {
break;
}
numbers.add(i);
}
if(numbers.size() > 0) {
minNumber = numbers.get(0);
}
for (int number : numbers) {
sum += number;
if(minNumber > number) {
minNumber = number;
}
if(number % 2 == 0) {
countEvenIntegers++;
}
if(number > 0 ) {
sumPositive += number;
}
}
nCount = numbers.size();
System.out.println("The minimum integer is " + minNumber + "\nThe count of integers is "
+ nCount + "\nThe sum of positive integers is " + sumPositive + "\nThe count of even integers in the sequence is " +
countEvenIntegers + "\nThe total sum is " + sum);
}
}
I am trying to run a program that outputs the sum of every digit of an entered in integer. How would I go about reading the number and outputting each digit?
Example: Input is 4053 the output would be "4+0+5+3 = 12".
import java.util.Scanner;
public class Digits{
public static void main(String args[]) {
//Scans in integer
Scanner stdin = new Scanner(System.in);
System.out.println("Enter in a number: ");
int number = stdin.nextInt();
//Set sum to zero for reference
int sum = 0;
int num = number; //Set num equal to number as reference
//reads each digit of the scanned number and individually adds them together
//as it goes through the digits, keep dividing by 10 until its 0.
while (num > 0) {
int lastDigit = num % 10;
sum = sum + lastDigit;
num = num/10;
}
}
}
That is the code I used for calculating the sum of the individual digits, now I just need help with outputting the individual digits. Any tips and tricks would be much appreciated.
import java.util.Scanner;
public class Digits{
public static void main(String args[]) {
//Scans in integer
Scanner stdin = new Scanner(System.in);
System.out.println("Enter in a number: ");
int number = stdin.nextInt();
//Set sum to zero for reference
int sum = 0;
int num = number; //Set num equal to number as reference
//reads each digit of the scanned number and individually adds them together
//as it goes through the digits, keep dividing by 10 until its 0.
String numToString = "";
while (num > 0) {
int lastDigit = num % 10;
numToString +=lastDigit+" + ";
sum = sum + lastDigit;
num = num/10;
}
//eliminate the last + sign
numToString = numToString.substring(0,numToString.lastIndexOf("+")).trim();
System.out.println(numToString +" = " +sum);
}
}
I am not sure what you mean by outputting but instead of this you can read the number as string and take each character and parse it to integers
Scanner stdin = new Scanner(System.in);
System.out.println("Enter in a number: ");
String number = stdin.next();
int[] result = new int[number.length];
for(int i=0;i<number.length;i++) {
result[i] = Integer.parseInt(number.charAt(i)+"");
}
return result;
You may read this like String and then divided by the number.
final Scanner s = new Scanner ( System.in );
final String line = s.nextLine ().trim ();
final char [] array = line.toCharArray ();
int sum = 0;
for ( final char c : array )
{
if ( !Character.isDigit ( c ) )
{
throw new IllegalArgumentException ();
}
sum = sum + Character.getNumericValue ( c );
}
System.out.println ( "sum = " + sum );
without a scanner you can do
StringBuilder sb = new StringBuilder();
String sep = "";
int ch;
long sum = 0;
while((ch = System.in.read()) > ' ') {
if (ch < '0' || ch > '9') {
System.out.println("Skipping " + (char) ch);
continue;
}
sb.append(sep).append((char) ch);
sep = " + ";
sum += ch - '0';
}
sb.append(" = ").append(sum);
System.out.println(sb);
Try this:
import java.util.*;
public class Digits {
public static void main(String [] args)
{
Scanner input = new Scanner (System.in);
System.out.println("Enter number -> ");
int number = input.nextInt();
int sum = 0;
String numStr = "" + number;
while(number > 0)
{
int lastDigit = number % 10;
sum += lastDigit;
number = number / 10;
}
for(int i = 0; i < numStr.length();i++)
{
System.out.print(numStr.charAt(i));
// Dont print an extra + operator at the end
if( i == numStr.length() - 1) continue;
else
System.out.print(" + ");
}
System.out.print(" = " + sum);
}
}
I have an assignment, and I need to use a loop to allow a user to enter ten different numbers in a programme which then adds up the variables.
I have found various pieces of code and stitched them together to create this:
import javax.swing.*;
import java.util.Scanner;
public class exercise6
{
public static void main (String []args)
{
//Input
String totalNum, num1, num2, num3, num4, num5, num6, num7, num8, num9, num10;
Scanner in = new Scanner (System.in);
System.out.println("Please enter ten numbers:");
int[] inputs = new int[10];
for (int i = 0; i < inputs.length; ++i)
{
inputs[i] = in.next();
}
//Process
totalNum = num1 + num2 + num3 + num4 + num5 + num6 + num7 + num8 + num9 + num10;
//Output
JOptionPane.showMessageDialog(null, "Total = " + totalNum);
}
}
It's not great, but it's the best I have so far. Please help?
You don't need the variables num1 to num10. You can simply sum up in the loop itself. Like:
int sum = 0;
for (int i = 0; i < 10; i++) {
sum += = in.next(); // sum = sum + in.next();
}
Furthermore you assigned your variables as Strings, but you need int. In your case it would print something like 1111111111, if the input would always be a 1.
Take a look here how you would handle Integers properly.
You can achieve that in two ways, either inside the loop itself just add the number or if you need to keep track of them for later just add them to the array.
import javax.swing.*;
import java.util.Scanner;
public class exercise6
{
public static void main (String []args)
{
String total;
Scanner in = new Scanner (System.in);
int numOfInputValues = 10;
System.out.println("Please enter ten numbers:");
int[] inputs = new int[numOfInputValues];
for (int i = 0; i < numOfInputValues; ++i)
{
// Append to array only if you need to keep track of input
inputs[i] = in.next();
// Parses to integer
total += in.nextInt();
}
//Output
JOptionPane.showMessageDialog(null, "Total = " + totalNum);
}
}
First of all, your class should be in CamelCase. First letter is always in capital letter.
Second, you don't need an array to save those numbers.
Third you should make a global variable that you can change with ease. That is a good practice.
And you should always close stream objects like Scanner, because they leak memory.
import java.util.Scanner;
public class Exercise6 {
public static void main(String[] args) {
int numberQuantity = 10;
int totalNum = 0;
Scanner in = new Scanner(System.in);
System.out.println("Please enter ten numbers:");
for (int i = 0; i <= numberQuantity; i++) {
totalNum += in.nextInt();
}
in.close();
System.out.println(totalNum);
}
}
So the simplest answer I found is:
import javax.swing.*;
import java.util.Scanner;
public class exercise6
{
public static void main (String []args)
{
//Input
int totalNum, num1;
totalNum = 0;
for (int numbers = 1 /*declare*/; numbers <= 10/*initialise*/; numbers ++/*increment*/)
{
num1 = Integer.parseInt(JOptionPane.showInputDialog("Input any number:"));
totalNum = totalNum + num1;
}
//Output
JOptionPane.showMessageDialog(null, "Total = " + totalNum);
Try this way I only re-edit your code:
import javax.swing.*;
public class InputNums {
public static void main(String[] args) {
int total = 0;
for (int i = 0, n = 0; i < 10;) {
boolean flag = false;
try {
n = Integer.parseInt(JOptionPane
.showInputDialog("Input any number:"));
} catch (NumberFormatException nfe) {
flag = true;
}
if (flag) {
flag = false;
JOptionPane.showMessageDialog(null,
"Invalid no Entered\nEnter Again...");
continue;
}
total += n;
i++;
}
JOptionPane.showMessageDialog(null, "Total = " + total);
}
}
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++;
}
Hi I am fairly new to java and trying to familiarize myself to it by doing some exercises online.
How do i properly code the while loop so that everytime the user input is wrong it asks the same question again and does not proceed to the next line of code
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class Array {
public static void main(String[] args) {
Scanner dataIn = new Scanner(System.in);
int entries = 0;
List<Integer> grade = new ArrayList<Integer>();
System.out.println("Enter number of students? ");
entries = dataIn.nextInt();
boolean checker = true;
while (checker){
for (int i = 0; i < entries; i++){
int input;
int addToList;
System.out.println("Enter grade for student: ");
input = dataIn.nextInt();
grade.add(input);
if (input >= 0 && input<= 100) {
}else {
System.out.println("invalid input try again..");
checker = false;
}
}
}
int sum = 0;
int count = grade.size();
double mean;
for (int grades : grade){
sum+= grades;
}
mean =(double)sum/count;
System.out.println("The Grades are: " + grade);
System.out.println("The number of elements in the Array is " + grade.size());
System.out.println("The average is: " + mean);
}
}
Your logic is backwards. You want the loop to continue if the input is incorrect. There are two ways to fix this:
Change while(checker) to while(!checker)
Change checker=false to checker=true after printing the error message. And set checker=false in the if branch.
It might help if you change the name of your checker variable to something that reads more directly. For example isInputCorrect reads very nicely when you write while(!isInputCorrect) and it also makes it more clear what the values of true and false represent.
try this :
boolean checker = true
for(int i=0;i< entries;i++){
int input;
System.out.println("Enter grade for student: ");
input = dataIn.nextInt();
while(checker){
if(input >= 0 && input<= 100){
grade.add(input);
checker = false;
}else{
System.out.println("invalid input try again..");
}
}
checker = true;
}
You could try this
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class Array {
public static void main(String[] args) {
Scanner dataIn = new Scanner(System.in);
int entries = 0;
List<Integer> grade = new ArrayList<Integer>();
System.out.println("Enter number of students? ");
entries = dataIn.nextInt();
for (int i = 0; i < entries; i++) {
int input;
do{
input = dataIn.nextInt();
if (input >= 0 && input <= 100) {
grade.add(input);
}else{
System.out.println("invalid input try again..");
}
}while(!(input >= 0 && input <=100));
}
dataIn.close();
int sum = 0;
int count = grade.size();
double mean;
for (int grades : grade) {
sum += grades;
}
mean = (double) sum / count;
System.out.println("The Grades are: " + grade);
System.out.println("The number of elements in the Array is " + grade.size());
System.out.println("The average is: " + mean);
}
}
instead of doing while(checker)
make a loop for while(running)
then send it to the keyboard.nextInt()
if its the wrongAnswer than it will loop, if its correct than set running to false
and have code that follows the while loop