We Keep Coding

Write a Java program that finds the second minimum of the absolute values of three numbers

I try to find the second minimum (2nd smallest) value. I find out sometimes my code work with a positive value if I have a negative value. The output will mess up.
int num1, num2, num3, minVal, secondMinVal;
System.out.print("Ener three integer numbers: ");
num1 = input.nextInt();
num2 = input.nextInt();
num3 = input.nextInt();
minVal = num1;
if (num2 < num1 && num2 < num3)
num2 = minVal;
else if (num3 < num1 && num3 < num2)
num3 = minVal;
System.out.println("The minimum of the absolute values of the entered numbers is " + Math.abs(minVal));
secondMinVal = num1;
if (num2 > num1 && num2 < num3)
num2 = secondMinVal;
else if (num3 > num1 && num3 < num2)
num3 = secondMinVal;
System.out.println("The second minimum value is " + secondMinVal);
I try to run with 7, -3, and 10 and the output will look like this:
Ener three integer numbers: 3 -1 10
The minimum of the absolute values of the entered numbers is 3
The second minimum value is 3

To assign a new value to the "minVal" variable, instead of
num2 = minVal;
you should use
minVal = num2;
The value of the variable which is to the right of the assignment operator "=" is assigned to the variable to the left of the assignment operator (for integer variables).
This logic applies to any integer variables ("secondMinVal", for example).

int num1, num2, num3, minVal, secondMinVal;
System.out.print("Ener three integer numbers: ");
num1 = input.nextInt();
num2 = input.nextInt();
num3 = input.nextInt();
if(num1 < num2 && num1 < num3)
minVal = num1;
else if (num2 < num3)
minVal = num2;
else
minVal = num3;
System.out.println("The minimum of the absolute values of the entered numbers is " + Math.abs(minVal));
secondMinVal = num1;
if (num2 > num1 && num2 < num3)
num2 = secondMinVal;
else if (num3 > num1 && num3 < num2)
num3 = secondMinVal;
System.out.println("The second minimum value is " + secondMinVal);
I think I just answer my question hahaha hope this can help anyone.

How do you write the conditions for the middle number when sorting 3 numbers in ascending order using if-else statements in java?

I've been trying different conditions but I can't seem to get it right. When I type 54, 53, 57, the output is correct. But when I type the same numbers in a different order, the output becomes 53, 0 , 57. Help please
This is my code for the middle number. I can't find out what's wrong.
if (num1<num2 && num1>num3){ //for middle number
secNum = num1;
}else if (num2<num1 && num2>num3){
secNum = num2;
}else if (num3<num1 && num3>num2){
secNum = num3;
}

Try this code if you're familiar with arrays
import java.util.*;
public class Main
{
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
int num1 = s.nextInt();
int num2 = s.nextInt();
int num3 = s.nextInt();
int arr[] = {num1,num2,num3};
Arrays.sort(arr);
System.out.println(arr[1]);
}
}

This Will Work
import java.util.*;
public class Main
{
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
int num1 = s.nextInt();
int num2 = s.nextInt();
int num3 = s.nextInt();
int secNum=0;
if(num2>num1 && num1>num3 || num3>num1 && num1>num2){
secNum=num1;
}
if(num1>num2 && num2>num3 || num3>num2 && num2>num1){
secNum=num2;
}
if(num1>num3 && num3>num2 || num2>num3 && num3>num1){
secNum=num3;
}
System.out.print(secNum);
}
}

Try this:
package com.company;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner s = new Scanner(System.in);
int num1 = s.nextInt();
int num2 = s.nextInt();
int num3 = s.nextInt();
int secNum = 0;
if (num1 < num2 && num1 < num3) {
secNum = Math.min(num2, num3);
} else if (num2 < num1 && num2 < num3) {
secNum = Math.min(num1, num3);
} else if (num3 < num1 && num3 < num2) {
secNum = Math.min(num1, num2);
}
System.out.println(secNum);
}
}

You have 3 numbers, which can be in 6 different orders:
num1, num2, num3
num1, num3, num2
num2, num1, num3
num2, num3, num1
num3, num1, num2
num3, num2, num1
But your code has only 3 if-cases, which check for 3 possible orders.
That is why 3 out of 6 cases are wrong.
(If numbers can have the same value, you need to check with <= or >=)
So to keep you algorithm style, it has to be like this:
public static void main(String[] args) {
int num1 = 59;
int num2 = 57;
int num3 = 55;
int secNum = 0;
if (num1 < num2 && num1 < num3) {
if (num2 < num3)
secNum = num2;
else
secNum = num3;
} else if (num2 < num1 && num2 < num3) {
if (num1 < num3)
secNum = num1;
else
secNum = num3;
} else if (num3 < num1 && num3 < num2) {
if (num1 < num2)
secNum = num1;
else
secNum = num2;
}
System.out.println(secNum);
}
But Java has a lot of better ways to sort numbers, so I can not recommend this approach.

Program is exiting at the wrong time

I've gotten my loop to work and exit when the value '999' is entered.
I'm not sure what to do from here as my program isn't functioning exactly how I want it to.
Currently, the loop is exiting after the values 'num1' 'num2' and 'num3' have been fulfilled. I'm wanting the program to exit as soon as the value '999' is entered; not when num1, 2 and 3 have all been entered.
Here's my code:
import java.util.Scanner;
public class SumAverage {
static Scanner keyboard = new Scanner(System.in);
public static void main(String[] args) {
System.out.printf("Please Enter the first number%n");
float num1 = keyboard.nextFloat();
System.out.printf("Please enter the second number%n");
float num2 = keyboard.nextFloat();
System.out.printf("Please enter the third number%n");
float num3 = keyboard.nextFloat();
float sum = (num1 + num2 + num3); //calculates sum
float average = (num1 + num2 + num3) / 3; //calculates average
for(int x = 0; x < 1; x++) {
if (num1 == 999 || num2 == 999 || num3 == 999) {
break;
}
System.out.printf("Sum: %.0f %nAverage: %.2f", sum, average);
}
}
}

If you really want the program to end as soon as a value of 999 is entered, you can change your main() method to this:
public static void main(String[] args) {
System.out.printf("Please Enter the first number%n");
float num1 = keyboard.nextFloat();
if (num1 == 999) {
System.exit(0);
}
System.out.printf("Please enter the second number%n");
float num2 = keyboard.nextFloat();
if (num2 == 999) {
System.exit(0);
}
System.out.printf("Please enter the third number%n");
float num3 = keyboard.nextFloat();
if (num3 == 999) {
System.exit(0);
}
float sum = (num1 + num2 + num3); // calculates sum
float average = (num1 + num2 + num3) / 3; // calculates average
System.out.printf("Sum: %.0f %nAverage: %.2f", sum, average);
}

If we look at the way your code is currently written, the user will always be required to input 3 values due to not having any kind of conditionals attached.
I recommend using "System.exit" with conditionals to test if the value the user is inputting is 999. Try going from there to see what you can make happen.
Here is some documentation regarding "System.exit" to help you gain a better understanding of how it works.

Your for loop is looping only once so what I think you'll need to do is change some aspects of code
public class Calculator{
public static void main(String[] args){
Scanner keyboard = new Scanner(System.in);
float num1;
float num2;
float num3;
while (true){ //This will run forever until we break the loop
num1 = keyboard.nextFloat();
if (num1 == 999){
break;
}
num2 = keyboard.nextFloat ();
if (num2 == 999){
break;
}
num3 = keyboard.nextFloat ();
if (num3 == 999){
break;
}
System.out.println("The average is: " + (num1 +num2+num3)/3);
}
}
}

Not getting the output to my program, just says "running..."

I know the sumOfMultiples method itself works and that the problem lies in the main method. When I run it, nothing happens and it just continuously runs. I'm using netbeans if that makes a difference.
package examp;
public class Main {
public static void main(String[] args) {
Main example = new Main();
System.out.println("The answer is " + example.sumOfMultiples(2, 3));
}
public int sumOfMultiples(int num1, int num2) {
int num1Total = 0;
int num2Total = 0;
//Total of the multiples of the first number.
while (num1 < 1000) {
num1Total = num1Total + num1;
num1 = num1 + num1;
}
//Total of the multiples of the second number.
while (num2 < 1000) {
if (num2 % num1 != 0) { //Makes sure it doesn't add multiples of the first number twice.
num2Total = num2Total + num2;
}
}
return num1Total + num2Total;
}
}
Sorry if it's a stupid question, just made an account a couple of minutes ago.

Your second while loop doesn't increment num2 (that is why it doesn't stop)
while (num2 < 1000) {
if (num2 % num1 != 0) {
num2Total = num2Total + num2;
}
num2++; // <-- like so.
// or, num2 = num2 + 1;
}

Its in infinite while loop:
while (num2 < 1000) {
if (num2 % num1 != 0) { //Makes sure it doesn't add multiples of the first number twice.
num2Total = num2Total + num2;
}
}
If you want to debug on your own then run this (I have added couple of System.out.println statements) and you will know how:
public int sumOfMultiples(int num1, int num2) {
int num1Total = 0;
int num2Total = 0;
//Total of the multiples of the first number.
while (num1 < 1000) {
num1Total = num1Total + num1;
num1 = num1 + num1;
System.out.println("num1"+num1);
}
//Total of the multiples of the second number.
System.out.println("num1:"+num1+" "+"num2:"+num2);
while (num2 < 1000) {
if (num2 % num1 != 0) { //Makes sure it doesn't add multiples of the first number twice.
num2Total = num2Total + num2;
}
}
return num1Total + num2Total;
}
With this you get num1=1024 num2=3 and you can see that it will never go in the if loop so second while loop goes in infinite loop. Once it enters second while loop then num2 remains constant so you need to add some incrementer like num2++ which may allow it to come back after finite loops.

Else Statement is a syntax error?

My code is probably amateur to a lot of you, so if any of my logic in it is messed up, that's okay. I'll fix that later. Just wondering if anyone could let me know why my else statement is coming up with: "Exception in thread "main" java.lang.Error: Unresolved compilation problem: Syntax error on token "else", delete this token"
I read some of the other questions on here and usually the problem is people are checking conditions (else (blah < bleh) {) with else, but I didn't do that.
import java.util.Scanner;
public class minOfThree {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner kb = new Scanner (System.in);
int num1, num2, num3, num4, min = 0;
System.out.println ("Please enter three numbers.");
System.out.print ("First value: ");
num1=kb.nextInt();
System.out.print ("Second value: ");
num2=kb.nextInt();
System.out.print ("Third value: ");
num3=kb.nextInt();
System.out.print ("Fourth value: ");
num4=kb.nextInt();
if (num1 < num2)
if (num1 < num3)
min=num1;
else
min=num3;
else if (num2 < num3)
min=num2;
else
min = num3;
***else*** {
min = num4;
}
System.out.println ("Minimum value is: " + min);
}
}

This could have been avoided if you used { and } properly:
if(num1 < num2) //"if" for if-else #1
{
if(num1 < num3) //"if" for if-else #2
{
min=num1;
}
else //"else" for if-else #2
{
min=num3;
} //complete end of if-else #2
}
else if(num2 < num3) //"else if" for if-else #1
{
min=num2;
}
else //"else" for if-else #1
{
min = num3;
} //complete end of if-else #1
else //"else" for nonexistent if-else == error
{
min = num4;
}
Here you can see that you have two elses on one if-else statement.
To fix it, use something like this:
min = Integer.MAX_VALUE; //minimum = maximum possible
if(num1 < min) //if num1 is less than current minimum...
{
min = num1; //current minimum = num1
}
if(num2 < min) //if num2 is less than current minimum...
{
min = num2; //current minimum = num2
}
if(num3 < min) //if num3 is less than current minimum...
{
min = num3; //current minimum = num3
}
if(num4 < min) //if num4 is less than current minimum...
{
min = num4; //current minimum = num4
}

There can only be one else for each if/else if. The else if (num2 < num3) part already has an else statement two lines below it. Maybe you are missing an if-statement somewhere?

Get into the habit of always writing if-else statements within brackets, then you will never have to wonder what statement goes with which test. I believe the following is what you want your code to look like:
if (num1 < num2) {
if (num1 < num3) {
min = num1;
} else {
min = num3;
}
} else {
if (num2 < num3) {
min = num2;
} else {
min = num3;
}
} else {
min = num4;
}
Although that does not make full sense because here you get two elses as well.

It happens because the else if doesn't create a new if/else branch. This is the correct indentation of how compiler interprets it.
if (num1 < num2)
if (num1 < num3)
min=num1;
else
min=num3;
else if (num2 < num3)
min=num2;
else
min = num3;
else
min = num4;
As you can see, it is not what you intended. So, as only one else statement is allowed, it doesn't compile. As already suggested, you should use braces.

If it were me, I would just use braces and move on ;-)
if () {
// hack
} else if () {
// hack hack
} else {
// hack hack
}
However, the logic you use is wrong, too, you could replace your last else by
if (min > num4) {
min = num4;
}

As per my knowledge if you are not writing multiple lines inside a scope (i.e. if-else statment), then there is not required of {}.
if (num1 < num2) //1st If Start
if (num1 < num3) //2nd If Start
min=num1;
else
min=num3; //2nd If Ends
else if (num2 < num3) //3rd If starts in else part of 1st If
min=num2;
else
min = num3; //3rd If Ends
***else*** { //This else part is not followed by any If Statement (Causes Error )
min = num4;
}
In this case your approach is correct but, you missed the start point of this last else.
Hope it will help you.

Your logic is amateur but it's ok? You are using two Else statements. That makes no sense. And you don't have brackets encapsulating the routines which is really confusing. What are you even trying to do? Are you trying to find the smallest number? Try this?
public static void main(String[] args){
int num1 = 4;
int num2 = 2;
int num3 = 3;
int num4 = 10;
int array[] = {num1, num2, num3, num4};
for (int i = 0; i < array.length; i++)
{
for (int j = 0; j < array.length-1; j++)
{
if (array[j] > array [j+1])
{
int x = array[j];
array[j] = array [j+1];
array [j+1] = x;
}
}
}
for (int i = 0; i < array.length; i++)
{
System.out.println(array[i]);
}
}

In this case yes because there's no sense of a second else clause. It would be unreachable code

Look at the first if statement. You didn't put the braces and other mistakes you made. like putting two else statements to one if statement.
import java.util.Scanner;
public class StackOver {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner kb = new Scanner (System.in);
int num1, num2, num3, num4, min = 0;
System.out.println ("Please enter three numbers.");
System.out.print ("First value: ");
num1=kb.nextInt();
System.out.print ("Second value: ");
num2=kb.nextInt();
System.out.print ("Third value: ");
num3=kb.nextInt();
System.out.print ("Fourth value: ");
num4=kb.nextInt();
if (num1 < num2){
if (num1 < num3)
min=num1;
else
min=num3;
}else if (num2 < num3)
min=num2;
else if(num4 < num3)
min = num4;
else
min = num3;
System.out.println ("Minimum value is: " + min);
}
}