We Keep Coding

Int array pushed through while loop until it reaches -1

I have to take a single line of user input, and calculate the average of all the numbers until it reaches -1 using a while loop. An example of user input could be something like 2 -1 6 which is why I've done it this way. I've figured out how to split this into an int array, but I can't figure out how to do the while loop portion.
System.out.println("user input")
String user = scan.nextLine();
String[] string = user.split(" ");
int[] numbers = new int[string.length];
for(int i = 0;i < string.length;i++) {
numbers[i] = Integer.parseInt(string[i]);
}
while ( > -1){
}

Class java.util.Scanner has methods hasNextInt and nextInt.
import java.util.Scanner;
public class Averages {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Enter series of integers on single line separated by spaces.");
System.out.println("For example: 2 -1 6");
int sum = 0;
int count = 0;
while (scan.hasNextInt()) {
int num = scan.nextInt();
if (num == -1) {
break;
}
sum += num;
count++;
}
if (count > 0) {
double average = sum / (double) count;
System.out.println("Average: " + average);
}
else {
System.out.println("Invalid input.");
}
}
}
Note that you need to cast count to a double when calculating the average otherwise integer division will be performed and that will not give the correct average.

I am assuming you mean, when user input number is -1. we should take average of all number before -1. that is was I am doing here.
System.out.println("user input")
String user = scan.nextLine();
int totalSum = 0;
double avg = 0;
String[] string = user.split(" ");
int[] numbers = new int[string.length];
for(int i = 0;i < string.length;i++) {
numbers[i] = Integer.parseInt(string[i]);
if(numbers[i]==-1){
avg = (double)totalSum / i;
break;
}
totalSum += numbers[i];
}
With only while loop
System.out.println("user input");
String user = scan.nextLine();
int totalSum = 0;
double avg = 0;
String[] string = user.split(" ");
int[] numbers = new int[string.length];
int i = 0;
numbers[i] = Integer.parseInt(string[i]);
while(numbers[i]!=-1) {
totalSum += numbers[i];
i++;
numbers[i] = Integer.parseInt(string[i]);
}
avg = (double)totalSum / i;

import java.util.Scanner;
public class Main
{
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("user input");
String user = scan.nextLine();
boolean found = false;
Double average = 0.0;
String[] string = user.split(" ");
int[] numbers = new int[string.length];
for(int i = 0;i < string.length && found == false ;i++) {
numbers[i] = Integer.parseInt(string[i]);
}
int t = 0;
while (found == false && t < string.length){
if(numbers[t] == - 1){
average = average/t;
found = true;
}
else{
average = (Double) average + numbers[t];
t++;
}
}
System.out.println("Average = " + average);
}
}

How to find factorial and show result of counting in console?

public class Car {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
System.out.println(n+"!="+factorial(n));
}
public static int factorial(int num) {
return (num == 0) ? 1 : num * factorial (num - 1);
}
}
how make this code to text in console 3! = 1*2*3 = 6?

Don't use recursion for this. Besides, it isn't really efficient or necessary.
Scanner in = new Scanner(System.in);
int n = in.nextInt();
int fact = 1;
String s = n + "! = 1";
for (int i = 2; i <= n; i++) {
fact *= i;
s += "*" + i;
}
s += " = ";
System.out.println(s + fact);

There can be many ways to do it e.g. you can build the required string or print the trail while calculating the factorial. In the following example, I have done the former.
As an aside, you should check the input whether it is a positive integer.
import java.util.Scanner;
public class Car {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("Enter a positive integer: ");
int n = in.nextInt();
if (n >= 0) {
StringBuilder strFact = new StringBuilder();
int fact = factorial(n, strFact);
if (strFact.length() > 0) {
// Delete the last '*'
strFact.deleteCharAt(strFact.length() - 1);
System.out.println(n + "!= " + strFact + " = " + fact);
} else {
System.out.println(n + "!= " + fact);
}
} else {
System.out.println("This is an invalid input.");
}
}
public static int factorial(int num, StringBuilder strFact) {
int fact;
if (num == 0) {
fact = 1;
} else {
fact = num * factorial(num - 1, strFact);
strFact.append(num + "*");
}
return fact;
}
}
A sample run:
Enter an integer: 3
3!= 1*2*3 = 6

Check if user enters negative numbers straight away?

I am trying to make a program where the user enters a number and the program computes the max and min and keeps asking untill it encounters negative.
DETAILED DESCRIPTION:-
However if the user enters a negative number at start up it should print "Max and min are undefined!" and end.
But if a positive number is entered the program prints max and min ,still keeps asking for more numbers untill a negative number is encountered ,seeing negative number it still prints max and min and then ends.
Is there a way to do this?
What i have tried is given below:-
import java.util.Scanner;
public class NegativeNum {
public static void main(String []args) {
Scanner keys = new Scanner(System.in);
System.out.println("Enter a number: ");
double num = keys.nextInt();
double Max = num+0.5;
double Min = num-0.5;
if(num<0) {
System.out.println("Max and Min undefined");
}
while(num>0) {
System.out.println("Max = " + Max);
System.out.println("Min = " + Min);
System.out.println("\nEnter another: ");
num = keys.nextInt();
}
{
num = num*-1;
System.out.println("Max = " + Max);
System.out.println("Min = " + Min);
System.out.println("Number is Negative! System Shutdown!");
System.exit(1);
}
}
}

Just calculate the maximum and minimum value during iteration
while(num>0) {
System.out.println("Max = " + Max);
System.out.println("Min = " + Min);
System.out.println("\nEnter another: ");
num = keys.nextInt();
if(Math.abs(num) > max) {
max = Math.abs(num);
}
if(Math.abs(num) < min) {
min = Math.abs(num);
}
}
System.out.println("Max = " + Max);
System.out.println("Min = " + Min);
System.out.println("Number is Negative! System Shutdown!");
System.exit(1);

import java.util.Scanner;
public class NegativeNum {
public static void main(String []args) {
Scanner keys = new Scanner(System.in);
System.out.println("Enter a number: ");
double num = keys.nextInt();
double Max = num+0.5;
double Min = num-0.5;
if(num<0) {
System.out.println("Max and Min undefined");
System.exit(1);
}
while(true) {
double temp_num = num;
num = Math.abs(num);
Max = num+0.5;
Min = num-0.5;
System.out.println("Max = " + Max);
System.out.println("Min = " + Min);
if ( temp_num < 0 )
break;
System.out.println("\nEnter another: ");
num = keys.nextInt();
}
System.out.println("Number is Negative! System Shutdown!");
}
}

import java.util.Scanner;
public class NegativeNum {
private static int entryCount = 0; // Count the Number of Entries
public static void main(String []args) {
Scanner keys = new Scanner(System.in);
System.out.println("Enter a number: ");
double num = keys.nextInt();
double Max = num+0.5;
double Min = num-0.5;
while(true) {
if( num < 0 && entryCount == 0) { // Make sure if it's first entry and it's negative too
System.out.println("Number is Negative! System Shutdown!");
System.exit(1);
}
System.out.println("Max = " + Max);
System.out.println("Min = " + Min);
System.out.println("\nEnter another: ");
num = keys.nextInt();
entryCount++;
}
}
}

This code successfully runs all the cases:-
import java.util.Scanner;
public class class2
{
public void positive(double num)
{
double Max = num+0.5;
double Min = num-0.5;
System.out.println("Max = " + Max);
System.out.println("Min = " + Min);
System.out.println("\nEnter another: ");
}
public void negative(double num,String k)
{
double Max = num+0.5;
double Min = num-0.5;
System.out.println("Max = " + Max);
System.out.println("Min = " + Min);
if(k=="terminate")
{
System.out.println("System is shutting down");
System.exit(1);
}
System.out.println("\nEnter another: ");
}
public static void main(String []args)
{
class2 obj=new class2();
Scanner keys = new Scanner(System.in);
System.out.println("Enter a number: ");
boolean bol=true;
String k="";
double num = keys.nextInt();
int count=1;
if(num<0 && count ==1)
{
k="terminate";
count=count+1;
System.out.println("Max and Min undefined");
System.exit(1);
System.out.println("\nEnter another: ");
num = keys.nextInt();
}
while(bol==true)
{
while(num>0)
{
count=count+1;
obj.positive(num);
num = keys.nextInt();
}
while(num<0 && count!=2)
{
k="terminate";
obj.negative(num,k);
num = keys.nextInt();
}
count=count+1;
}
}
}

How can I get this program to print out the numbers the user entered?

Here's my code:
import java.util.*;
public class InputSum
{
public static void main(String[]args)
{
Scanner input = new Scanner(System.in);
System.out.print("Please enter integer values (-1 to to display numbers & sum): ");
int i = input.nextInt();
int j = 0;
while (i != -1)
{
j += i;
i = input.nextInt();
}
System.out.println("Entered Number: " + i);
System.out.println("The Sum: " + j);
}
}
As of now my output is:
Entered Number: -1
The Sum: (Sum of the numbers entered)

Print them inside the loop :
while (i != -1)
{
System.out.println("Entered Number: " + i);
j += i;
i = input.nextInt();
}
System.out.println("The Sum: " + j);
Or it you want to print them in a single line :
List numbers = new ArrayList<Integer>();
while (i != -1)
{
numbers.add(i);
j += i;
i = input.nextInt();
}
System.out.println("Entered Numbers: " + numbers);
System.out.println("\nThe Sum: " + j);

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
ArrayList<Integer> numbers = new ArrayList<Integer>();
System.out
.print("Please enter integer values (-1 to to display numbers & sum): ");
int i = input.nextInt();
int j = 0;
while (i != -1) {
numbers.add(i);
j += i;
i = input.nextInt();
}
System.out.println("Entered Numbers: ");
for (int a = 0; a < numbers.size(); a++) {
System.out.print(" " + numbers.get(a));
}
System.out.println("The Sum: " + j);
}
This should work to print the numbers. You can use an arraylist to store the numbers and then if you need them for later calculations they are still stored in the arraylist.

package net.rajkannan.stackoverflow;
import java.util.*;
public class InputSum {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out
.print("Please enter integer values (-1 to to display numbers & sum): ");
int i = input.nextInt();
int j = 0;
String numbers = "";
while (i != -1) {
j += i;
numbers = numbers + i + " ";
i = input.nextInt();
}
System.out.println("Entered Numbers: " + numbers);
System.out.println("The Sum: " + j);
}
}

To check if a number is Armstrong number using java

this is my program:
public class ArmstrongNumber {
public static void main(String args[]) {
int n = 0, temp = 0, r = 0, s = 0;
Scanner in = new Scanner(System.in);
System.out.println("Enter a number ");
if (in.hasNextInt()) {
n = in.nextInt(); // if there is another number
} else {
n = 0;
}
temp = n;
while (n != 0) {
r = n % 10;
s = s + (r * r * r);
n = n / 10;
}
if (temp == s) {
System.out.println(n + " is an Armstrong Number");
} else {
System.out.println(n + " is not an Armstrong Number");
}
}
}
output:
Exception in thread "main" java.lang.NoClassDefFoundError
I tried it using DataInputStream but still getting same error.

// To check the given no is Armstrong number (Java Code)
class CheckArmStrong{
public static void main(String str[]){
int n=153,a, b=0, c=n;
while(n>0){
a=n%10; n=n/10; b=b+(a*a*a);
System.out.println(a+" "+n+" "+b); // to see the logic
}
if(c==b) System.out.println("Armstrong number");
else System.out.println(" Not Armstrong number");
}
}

Find any digit is Armstrong number or not using loop
for(int arm_num = 0 ; arm_num < 100000 ; arm_num++)
{
String[] data = String.valueOf(arm_num).split("(?<=.)");
int lngth = String.valueOf(arm_num).length();
int arm_t_num = 0;
int ary[] = new int[lngth];
for(int i = 0 ; i < lngth ; i++)
{
ary[i] = Integer.parseInt(data[i]);
for(int x = 0 ; x < lngth-1 ; x++)
{
ary[i] = ary[i] * Integer.parseInt(data[i]);
}
arm_t_num+=ary[i];
}
if(arm_num == arm_t_num)
{
System.out.println("Number is ArmStrong : "+arm_num);
}
}

you need to set CLASS_PATH variable and point it to where ever your class file is
then this should work
I have tried it locally, refer my answer to check how to set class path and how to compile and run java code using command prompt

//This is my program to check whether the number is armstrong or not!!
package myprogram2;
public class Myprogram2 {
public static void main(String[] args)
{
String No="407";
int length_no=No.length();
char[] S=new char[length_no];
int[] b = new int[length_no];
int arm=0;
for(int i=0;i<length_no;i++)
{
S[i]=No.charAt(i);
b[i]=Character.getNumericValue(S[i]);
//System.out.print(b[i]);
arm=arm + (b[i]*b[i]*b[i]);
System.out.println(arm);
}
//System.out.println(" is the number \n now Checking for its Armstrong condition");
int orgno = Integer.parseInt(No);
if (orgno==arm)
System.out.println("YESm its an armstrong");
else
System.out.println("\n<<Not an armstrong>>");
//System.out.println(length_no);
System.out.println("Original number is "+orgno);
System.out.println("Sum of cubes "+arm);
}
}

There are a couple of nice String-based solutions and numeric solutions with single-letter variable names.
Consider this to make sense of how it works numerically, which includes a couple of interesting numeric tricks:
import java.io.*;
public class Armstrong
{
public static void main(String args[]) throws IOException
{
InputStreamReader read = new InputStreamReader(System.in);
BufferedReader in = new BufferedReader(read);
int modifiedNumber, originalNumber, modifiedNumberWithUnitsDigitZero,
unitsDigit, runningSum;
System.out.println("Enter your number:");
modifiedNumber = Integer.parseInt(in.readLine());
runningSum = 0;
originalNumber = modifiedNumber;
while(modifiedNumber > 0)
{
modifiedNumberWithUnitsDigitZero = modifiedNumber / 10 * 10;
unitsDigit = modifiedNumber - modifiedNumberWithUnitsDigitZero;
runningSum += unitsDigit * unitsDigit * unitsDigit;
modifiedNumber = modifiedNumber / 10;
}
System.out.println("The number " + originalNumber
+ (originalNumber == runningSum ? " IS" : " is NOT")
+ " an Armstrong number because sum of cubes of digits is " + runningSum);
}
}

import java.util.Scanner;
public class Amst {
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
System.out.println("Enter The No. To Find ArmStrong Check");
int i = sc.nextInt();
int sum = 0;
for(int j = i; j>0 ; j = j/10){
sum = sum + ((j%10)*(j%10)*(j%10));
}
if(sum == i)
System.out.println("Armstrong");
else
System.out.println("Not Armstrong");
}
}

For 'N' digit amstrong number
package jjtest;
public class Amstrong {
public static void main(String[] args) {
// TODO Auto-generated method stub
int num=54748;
int c=0;
int temp=num;
int b=1;
int length = (int)(Math.log10(num)+1);
while(num>0){
int r = num%10;
num=num/10;
int a =1;
for(int i=1;i<=length;++i){
b=b*r;
}
c = c + b;
b=1;
}
System.out.println(c);
if(c==temp){
System.out.println("its an amstrong number");
}else{
System.out.println("its not an amstrong number");
}
}
}

This is the simple logic for Armstrong number program :
for (int i = number; i > 0; i = i / 10)
{
remainder = i % 10;
sum = sum + remainder * remainder * remainder;
}
if(sum == number)
{
System.out.println("\n" + number + " is an Armstrong Number\n");
}
Reference :
http://topjavatutorial.com/java/java-programs/java-program-to-check-if-a-number-is-armstrong-number/

import java.util.Scanner;
/* a number is armstrong if the sum of cubes if individual digits of
a number is equal to the number itself.for example, 371 is
an armstrong number. 3^3+7^3+1^3=371.
some others are 153,370,407 etc.*/
public class ArmstrongNumber {
public static void main(String args[]) {
int input, store, output=0, modolus;
Scanner in = new Scanner(System.in);
System.out.println("Please enter a number for ckecking.");
input = in.nextInt();
store = input;
while(input != 0) {
modolus = input % 10;
output = output + (modolus * modolus * modolus);
input = input / 10;
}
System.out.println(output);
if(store == output) {
System.out.println("This is an armstrong number.");
} else {
System.out.println("This is not an armstrong number.");
}
in.close();
}
}

import java.util.*;
public class ArmstrongNumber
{
public static void main( String[] args )
{
int n = 0, temp = 0, r = 0, s = 0;
Scanner in = new Scanner(System.in);
System.out.println("Enter a number ");
if (in.hasNextInt()) {
n = in.nextInt(); // if there is another number
} else {
n = 0;
}
temp = n;
while (n != 0) {
r = n % 10;
s = s + (r * r * r);
n = n / 10;
}
if (temp == s) {
System.out.println(temp + " is an Armstrong Number");
} else {
System.out.println(temp + " is not an Armstrong Number");
}
}
}
You missed to import java.util package
Change n to temp in S.O.P

import java.util.Scanner;
public class AmstrongNumber {
public static void main(String[] args) {
System.out.println("Enter the number");
Scanner scan=new Scanner(System.in);
int x=scan.nextInt();
int temp2=0;
String s1 = Integer.toString(x);
int[] a = new int[s1.length()];
int[] a1 = new int[s1.length()];
for (int i = 0; i < s1.length(); i++){
a[i] = s1.charAt(i)- '0';
int temp1=a[i];
a1[i]=temp1*temp1*temp1;
}
for (int i = 0; i < s1.length(); i++){
temp2=temp2+a1[i];
if(i==s1.length()-1){
if(x==temp2){
System.out.println("Amstrong num");
}else{
System.out.println("Not !");
}
}
}
}
}

private static boolean isArmstrong(int num) {
int totalSum = 0;
int copyNum = num;
while (num != 0) {
int reminder = num % 10;
int cubeOfReminder = reminder * reminder * reminder;
totalSum = totalSum + cubeOfReminder;
num = num / 10;
}
if (copyNum == totalSum)
return true;
return false;
}

public class Testamstrong
{
public static void main(String...strings) {
int num = 153,temp;
temp = num;
if(temp == amstrongNumber(num)) {
System.out.println("Number is amstrong number...");
}
else {
System.out.println("Number is not amstrong number...");
}
}
public static int amstrongNumber(int num) {
int count=0,sum=0;
count = String.valueOf(num).length();
char[] ch = String.valueOf(num).toCharArray();
for(char ch1:ch) {
int num1 = Character.getNumericValue(ch1);
sum += Math.pow(num1, count);
}
return sum;
}
}

Find Armstrong number using for loops (with example)
import java.util.*;
public class ArmstorngNumber {
public static void main(String args[]) {
int cube, num, quo, n;
int s = 0;
do
{
System.out.println("Enter Your Number");
Scanner sc = new Scanner(System.in);
num = sc.nextInt();//153
n = num;
for (int i = 0; i < 10; i++) {
int rem = num % 10;//3
quo = num / 10; //15
cube = rem * rem * rem;//9
s = s + cube;//0+9
num = quo;//0
}
System.out.println(s);
System.out.println(n);
if (s == n) {
System.out.println("The number is Armstrong");
System.out.println("-------------------------------------");
}
else {
System.out.println("The number is not Armstrong");
System.out.println("-------------------------------------");
}
}
while (n > 0);
}
}

Check the Armstrong number of any number [java] [Armstrong]
import java.util.*;
public class Armstrong {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("enter any number?");
int x = sc.nextInt();
int n=0;
int number = x;
int j =x;
int result = 0 ,remainder;
while (x!=0) {
x/=10;
++n;
}
for(;j>0 ;j=j/10) {
remainder=j%10;
result+=Math.pow(remainder, n);
}
if (number==result) {
System.out.print(number +" is Armstrong ");
}
else
System.out.print(number +" is not Armstrong");
}
}

here is my code, please check if this works for you!
import java.util.Scanner;
public class Armstromg {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Please enter the number: ");
int num = sc.nextInt();
int length = 0;
int temp1 = num;
while(temp1 != 0) {
temp1/=10;
length+=1;
}
int result = 1;
int temp2 = num;
for(int i = 1; i <= length; i++) {
temp2 = temp2 % 10;
result*=Math.pow(temp2,length);
}
if(result == num) {
System.out.print("The number is an armstrong number!");
} else {
System.out.print("The number is not an armstrong number");
}
}
}

package Loops;
public class ArmStrongNumber {
public static void main(String[] args) {
int digit1, digit2, digit3;
int number = 153;
int temp = number;
digit1 = number % 10;
number = number / 10;
digit2 = number % 10;
number = number / 10;
digit3 = number % 10;
if ((digit1 * digit1 * digit1) + (digit2 * digit2 * digit2) + (digit3 * digit3 * digit3) == temp) {
System.out.println(+temp + " Number is Armstrong ");
} else {
System.out.println("Number is not Armstrong");
}
}
}

//Not limited to 3 digit integers
public static void main(String[] args)
{
int num = 54748,a,sum=0;
int x = num;
int p =Integer.toString(num).length();
while (num !=0)
{
a = num%10;
num = num/10;
sum = sum + (int) Math.pow(a, p);
}
if (x==sum)
System.out.println("Its an Armstrong number");
else
System.out.println("Not an Armstrong number");
}
}

Scanner input = new Scanner (System.in);
int num , counter = 0 ,temp;
System.out.print("Enter Nmber :");
num = input.nextInt();
int lnum = num;
while ( num != 0 ){
num = num/10 ;
counter++;
}
int store_num_keyboard_input = lnum;
int new_tot = 0;
int c = counter;
while(lnum > 0){
temp = lnum % 10;
lnum = lnum / 10 ;
int m = 0; //m is counter
int tot = 1;
while (m != c){
tot = tot * temp;
m++;
}
new_tot = new_tot + tot;
}
System.out.println("new total "+ new_tot );
if(new_tot == store_num_keyboard_input){
System.out.println(store_num_keyboard_input + " is an Armstrong number" );
}
else{
System.out.println(store_num_keyboard_input + " is not an Armstrong number" );
}

My answer using JAVA 8
tested for..[1, 153, 370, 371, 407]
public class Armstrong {
public static boolean isArmstrong(int num) {
return num == getArmstrongSum(num);
}
public static int getArmstrongSum(int num) {
int pow = String.valueOf(num).length();
return IntStream.iterate(num, i -> i / 10)
.limit(pow)
.map(i -> (int) Math.pow(i % 10, 3))
.sum();
}
public static void main(String[] args) {
System.out.println(isArmstrong(153));
}
}
Thank you.