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Issue with my if else statement in a do while loop

My do-while loop is supposed to print out numbers from 1 - 106 (including 1 and 106)
whats supposed to happen:
multiples of 3 are supposed to print out Big,
multiples of 5 are supposed to print out Mean,
multiples of 7 are supposed to print out Bugs,
multiples of 3 and 5 are supposed to print out BigMean,
multiples of 3 and 7 are supposed to print out BigBugs,
multiples of 5 and 7 are supposed to print out MeanBugs,
multiples of 3, 5 and 7 are supposed to print out BigMeanBugs.
What actually happens:
my do-while loop only runs the first "if" statement. Any help?
My code:
public static void main(String [] args){
int i = 0;
do{
++i;
if(i %3 == 0){
System.out.print("Big, ");
if(i %5 ==0){
System.out.print("Mean, ");
}
if(i %7 ==0){
System.out.print("Bugs, ");
}
if((i %3 == 0) && (i %5 == 0)){
System.out.print("BigMean, ");
}
if((i %3 == 0) && (i %7 == 0)){
System.out.print("BigBugs, ");
}
}else if((i %5 == 0) && (i %7 == 0)){
System.out.print("MeanBugs, ");
}else if((i %3 == 0) && (i %5 == 0) && (i %7 ==0)){
System.out.print("BigMeanBugs, ");
}else{
System.out.print(i + " ");
}
}while(i<=106);
}//closing main

As I could see your problem is probably that your if-statements are inside of first if-statement, so maybe you want this:
public class BigMeanBugsDoWhileLoop
{
public static void main(String [] args)
{
int i = 0;
do
{
++i;
boolean bug = false;
String result = "";
if(i %3 == 0)
{
result += "Big";
bug = true;
}
if(i %5 ==0)
{
result += "Mean";
bug = true;
}
if(i %7 ==0)
{
result += "Bugs";
bug = true;
}
if(!bug)
{
System.out.println(i + "");
}
else
{
System.out.println(result);
}
}while(i<106);
}//closing main
} // closing class
You don't need other if-statements because you don't use break so other expressions will be evaluated before next iteration.

First, if something is divisible by 3 and 7 it is divisible by 21.
Second, if you reverse the order, you will catch divisible by 3 and 5 before divisible by 3 or 5 separately (assuming that is what you want). If you do it the other way you may print the values prematurely or miss them altogether before checking the other possible factors. This behavior is also dependent on if vs if/else if statements.
I have limited the printout to 25 to avoid a long list. Modify as you see fit.
public class BigMeanBugsDoWhileLoop {
public static void main(String[] args) {
int i = 1;
do {
String bugType = "";
if (i % 105 == 0) {
bugType = "BigMeanBugs"; // 3 5 7
} else if (i % 35 == 0) {
bugType = "MeanBugs"; // 5 7
} else if (i % 21 == 0) {
bugType = "BigBugs"; // 3 7
} else if (i % 15 == 0) {
bugType = "BigMean"; // 3 5
} else if (i % 7 == 0) {
bugType = "Bugs"; // 7
} else if (i % 5 == 0) {
bugType = "Mean"; // 5
} else if (i % 3 == 0) {
bugType = "Big"; // 3
}
System.out.println(bugType.isEmpty() ? i : bugType);
i++;
} while (i <= 25);
}// closing main
} // closing class
Prints this.
1
2
Big
4
Mean
Big
Bugs
8
Big
Mean
11
Big
13
Bugs
BigMean
16
17
Big
19
Mean
BigBugs
22
23
Big
Mean

You have to increment the value of i in the end of loop
public static void main(String [] args){
int i = 1;
do{
if(i %3 == 0){
System.out.print("Big, ");
if(i %5 ==0){
System.out.print("Mean, ");
}
if(i %7 ==0){
System.out.print("Bugs, ");
}
if((i %3 == 0) && (i %5 == 0)){
System.out.print("BigMean, ");
}
if((i %3 == 0) && (i %7 == 0)){
System.out.print("BigBugs, ");
}
}else if((i %5 == 0) && (i %7 == 0)){
System.out.print("MeanBugs, ");
}else if((i %3 == 0) && (i %5 == 0) && (i %7 ==0)){
System.out.print("BigMeanBugs, ");
}else{
System.out.print(i + " ");
}
i++;
}while(i<=106);
}//closing main
} // closing class

How to Get Rid of These Extra Spaces?

This program asks to list out all the possible years which are leap years from 2014 to 2114, which I did correctly in the program shown below and the years to be listed with a space in each with 10 in every row. Once 10 years are listed, you go to the next. line. The only problem which I notice is that there are 3 empty lines between every 10 rows of years. How can I alter the program so there are no spaces between these rows.
public class fiveTwoSeven {
public static void main(String[] args)
{
int year2 = 2114;
int count = 0;
for (int year1 = 2014; year1 <= year2; year1++)
{
if (year1 % 4 == 0 && !(year1 % 100 == 0))
{
System.out.print(year1 + " ");
count++;
}
if (count % 10 == 0 && !(count == 0))
{
System.out.println();
}
}
}
}

Just change your second if condition block to this:
if (count % 10 == 0 && !(count == 0))
{
System.out.println();
count = 0;
}
It is creating problem when count is 10 or 20 or 30 or ....
I am giving explanation for 10...
From 2014, according to your logic 10th leap year is 2052. So after printing 2052, you are printing a new line. And for 2053, 2054 and 2055, your count is still 10. So second if block is printing another new line for each one.

Try it:
if (count % 10 == 0 && !(count == 0))
{
System.out.println();
count = 0;
}
Or
int year2 = 2114;
int count = 0;
for (int year1 = 2014; year1 <= year2; year1++)
{
if (year1 % 4 == 0 && !(year1 % 100 == 0))
{
count++;
System.out.print(year1 + " ");
if(count % 10 == 0 && !(count == 0)) {
System.out.println();
count = 0;
}
}
}
Output:
Note:
You just need to reset the value of count after it reaches to 10 so that cursor goes to the next line.

You should only println() in your if block (since that is when you output leap years). More importantly, your algorithm has a bug. Years that are multiples of 400 are leap years (2000 and 2400 are both leap years). I suggest you save the leap year as a local boolean. Something like,
public static void main(String[] args) {
int count = 0, year1 = 2014, year2 = 2114;
for (; year1 <= year2; year1++) {
boolean leapYear = false;
if (year1 % 4 == 0) {
if (year1 % 100 != 0) {
leapYear = true;
} else if (year1 % 400 == 0) {
leapYear = true;
}
}
if (leapYear) {
System.out.print(year1 + " ");
count++;
if (count % 10 == 0) {
System.out.println();
}
}
}
}

How can I get this program to print out ten items per line seperated by 1 space?

Here's my code so far
public class DivisibleBy5and6
{
public static void main (String []args)
{
for (int i = 100; i <= 200; i++)
{
boolean num = (i % 5 == 0 || i % 6 == 0) && !(i % 5 == 0 && i % 6 == 0);
if (num == true)
System.out.println(i + " is divisible");
}
}
}
Like stated previously how can I get the output to print out 10 items per line separated by a space?

How about:
int count = 0;
for (int i = 100; i <= 200; i++) {
boolean num = (i % 5 == 0 || i % 6 == 0) && !(i % 5 == 0 && i % 6 == 0);
if (num == true) {
count++;
System.out.print(i + " is divisible ");
if(count >= 10) {
System.out.println();
count -= 10;
}
}
}

Output is not getting displayed

I am writing a simple java program to find the smallest number which is divisible by all the numbers from 1 to 20.
I have written the following code:
package smallmultiple;
public class SmallMultiple {
public static void main(String[] args) {
int sml = 0;
outerloop:
for (int i = 40; i < 100000; i++) {
int j=1;
do {
if(i%j==0)
j++;
} while(j<21);
if(j==20) {
sml=i;
break outerloop;
}
}
System.out.println(sml);
}
}
It is not giving any error but it is not giving any output.

You can try this which is a bit faster than yours solution:-
for(int i = 190; ; i += 190) {
if(i % 3 == 0
&& i % 4 == 0
&& i % 6 == 0
&& i % 7 == 0
&& i % 8 == 0
&& i % 9 == 0
&& i % 11 == 0
&& i % 12 == 0
&& i % 13 == 0
&& i % 14 == 0
&& i % 15 == 0
&& i % 16 == 0
&& i % 17 == 0
&& i % 18 == 0
&& i % 20 == 0) {
System.out.println(i);
break;
}
}
You can also check out this article.

You are incrementing j only if i is perfectly divisible by j. Shouldn't you break or exit the do.. while loop of atleast one number is not divisible? Not doing so is causing infinite loop I believe. It should be something like
if(i%j==0) {
j++;
}
else {
break;
}

its simple. Let me explain your loop. First, i = 40 and j = 1, its ok. Then j++.Next i = 40 and j = 2, its still correctly. Then j++ again. Now i = 40, j = 3 and i%j !=0 => j cannot ++ and j still equal 3. And you see, j = 3 is still satisfy your loop ( j < 21) then it loop and loop forever. This is the reason why you cant get any output. You can use your IDE debugging to find this mistake. Sorry my English not good.

In java, to respect the object oriented best practise, it's not advised to user labels, try this :
public class NumberTool {
public static void main(String[] args) {
System.out.println("Smallest number is : " + getSmallestNumberDividedByOneToTwnety());
}
public static int getSmallestNumberDividedByOneToTwnety() {
for ( int i = 40; i <= 2147483647; i++) {
if (isNumberDivdedByOneToTwenty(i)) {
return i;
}
}
return 0;
}
public static boolean isNumberDivdedByOneToTwenty(int numberToTest) {
for (int i = 1; i <= 20; i++) {
if (numberToTest % i != 0) {
return false;
}
}
return true;
}
}
Output is:
Smallest number is : 232792560

Why isn't my FizzBuzz code processing both if statements when they both match? [duplicate]

This question already has answers here:
Conditional statement true in both parts of if-else-if ladder
(4 answers)
Closed 2 years ago.
For those who don't know, FizzBuzz is the following problem:
Write a program that prints the numbers from 1 to 100. But for
multiples of three print "Fizz" instead of the number and for the
multiples of five print "Buzz". For numbers which are multiples of
both three and five print "FizzBuzz".
Every FizzBuzz solution I find is either some crazy esoteric solution made for the sake of being original, or your basic if-else chain:
for(int i = 1; i <= 100; i++) {
if(i % 3 == 0 && i % 5 == 0) {
System.out.println("FizzBuzz");
} else if (i % 3 == 0) {
System.out.println("Fizz");
} else if (i % 5 == 0) {
System.out.println("Buzz");
} else {
System.out.println(i);
}
}
I am looking for a simple solution that aims to take out the "FizzBuzz" if statement. I have this in mind:
for(int i = 1; i <= 100; i++) {
if (i % 3 == 0)
System.out.print("Fizz");
if (i % 5 == 0)
System.out.println("Buzz")
else
System.out.println(i);
}
But this doesn't work. I assume it would be able to print FizzBuzz by entering both ifs, for Fizz and for Buzz, but if the number is, for example, 3, it would print Fizz3. How do I avoid this?

What you're trying to do is
if (a)
...
if (b)
...
else // if neigther a nor b
...
This is simply not possible. An else can only belong to a single if. You have to go with the slightly longer variant.
To avoid doing redundant evaluations of the modulo operator, you could formulate the loop body as
boolean fizz = i % 3 == 0;
boolean buzz = i % 5 == 0;
if (fizz)
System.out.print("Fizz");
if (buzz)
System.out.print("Buzz");
if (!(fizz || buzz))
System.out.print(i);
System.out.println();
Another one would be
String result = "";
if (i % 3 == 0) result = "Fizz";
if (i % 5 == 0) result += "Buzz";
if (result == "") result += i;
System.out.println(result);

Your first if statement is all alone.
So, your code hits the first statement, which is ONLY an if statement, and then goes on to the next, which is an if/else statement.
RosettaCode has a good example without using AND operators.
int i;
for (i = 0; i <= 100; i++) {
if ((i % 15) == 0)
cout << "FizzBuzz" << endl;
else if ((i % 3) == 0)
cout << "Fizz" << endl;
else if ((i % 5) == 0)
cout << "Buzz" << endl;
else
cout << i << endl;
}

If your only goal is to avoid using &&, you could use a double negation and DeMorgan's laws:
for(int i = 1; i <= 100; i++) {
if(!(i % 3 != 0 || i % 5 != 0)) {
System.out.println("FizzBuzz");
} else if (i % 3 == 0) {
System.out.println("Fizz");
} else if (i % 5 == 0) {
System.out.println("Buzz");
} else {
System.out.println(i);
}
}
You can avoid && using the fact that i % 3 == 0 and i % 5 == 0 implies i % 15 == 0, as per RFC1337's answer.
Another solution is to use a switch on the remainder (mod 15, which is 5 times 3):
for(int i = 1; i <= 100; i++) {
final int mod = i % 15;
switch (mod) {
case 0:
case 3:
case 6:
case 9:
case 12:
System.out.print("Fizz");
if (mod != 0) break;
case 5:
case 10:
System.out.print("Buzz");
break;
default:
System.out.print(i);
}
System.out.println();
}

This is my solution. Granted, it's a bit convoluted (as in roundabout), but I believe it suits your requirement.
int main()
{
char fizzpass=0;
unsigned short index=0;
for(index=1;index<=100;index++)
{
if(0 == (index%3))
{
printf("Fizz");
fizzpass = 1;
}
if(0 == (index%5))
{
if(1 == fizzpass)
{
fizzpass = 0;
}
printf("Buzz\n");
continue;
}
if(1 == fizzpass)
{
fizzpass = 0;
printf("\n");
continue;
}
printf("%d\n",index);
}
return 0;
}
Regards.

Just add a flag variable and use System.out.print:
package com.stackoverflow;
public class FizzBuzz {
public static void main(String[] args) {
for (int i = 1; i <= 100; i++) {
boolean printed = false;
if (i % 3 == 0) {
printed = true;
System.out.print("Fizz");
}
if (i % 5 == 0) {
printed = true;
System.out.print("Buzz");
}
if (printed) {
System.out.println();
} else {
System.out.println(i);
}
}
}
}

This doesn't take out the if statements but does not use the && (and) operator, you could flip the binary operators.
//FizzBuzz Case
if(!(a % 3 != 0 || a % 5 != 0)){ //flips
result[index] = "FizzBuzz";
index++;
}

Don't use an if statement at all.
import java.util.*;
import java.lang.*;
import java.io.*;
class FizzBuzz
{
public static void main (String[] args) throws java.lang.Exception
{
String[] words = {"", "Fizz", "Buzz"};
String[] nwords = {"", ""};
for(int i = 1; i < 101; ++i)
{
int fp = (i % 3 == 0) ? 1 : 0;
int bp = ((i % 5 == 0) ? 1 : 0) * 2;
int np = ((fp > 0 || bp > 0) ? 1: 0);
nwords[0] = Integer.toString(i);
System.out.print(words[fp]);
System.out.print(words[bp]);
System.out.println(nwords[np]);
}
}
}
See it on ideone.

public class fizzbuzz
{
public static void main(String[] args)
{
String result;
for(int i=1; i<=100;i++)
{
result=" ";
if(i%3==0)
{
result=result+"Fizz";
}
if(i%5==0)
{
result=result+"Buzz";
}
if (result==" ")
{
result=result+i;
}
System.out.println(result);
}
}
}
This is the most efficient way I could come up with. Hope it helps! :)

Crazy albeit unrelated solution done in Python3
#!/usr/bin/python3
for i in range(1,100):
msg = "Fizz" * bool(i%3==0)
msg += "Buzz" * bool(i%5==0)
if not msg:
msg = i
print(msg)