Help with loop logic

[Abhradeep Banerjee]

basic java code kind of forgotten need some hel

package oddnumbers;
public class Oddnumbers {

    
    public static void main(String[] args) {
        System.out.println("NO" + "     "+"ODD NUMBERS");
          
        int x= 0;
        int z=-1;
        
      while( x < 15 ){
         x=x+5; //will increment by 5 everytime
       
       System.out.print( x + "      " ); 
             while (z<5 ){ 
             
                 z=z+2;
                 System.out.print(z + "  " );
           
         }
             System.out.println();    
             
             
      }//end of outer while loo
    
    }//end main method
}    //end class

this will show the following:

NO ODD NUMBERS
5 1 3 5
10
15



but what i want is :
NO ODD NUMBERS
5 1 3 5
10 1 3 5 7 9
15 1 3 5 7 9 11 13 15


thanks guys hope to hear from you
o

[Winston Gutkowski]

Abhradeep Banerjee wrote:thanks guys hope to hear from you

Question: what does

while (z<5) {   
   z=z+2;
   ...
}

do?

Answer that, and I think you'll work out what your problem is.

Winston

[Abhradeep Banerjee]

while (z<5) {
z=z+2;
...
}

do?

Answer that, and I think you'll work out what your problem is.


i know it will keep displaying numbers up to 5 and z increments by 2.

[Jan Hoppmann]

Abhradeep Banerjee wrote:i know it will keep displaying numbers up to 5 and z increments by 2.

Right. But you don't want 5 to be your upper boundary, do you?
And what value does z have in your second and third loop?

[Abhradeep Banerjee]

only for the first line

2nd line will be 9
3rd will be 15

[Jan Hoppmann]

So you don't want the odd numbers that are less than 5, but rather less than x, right? That should point you in the right direction

[Greg Brannon]

Please write meaningful thread titles. I changed it to one I think describes the topic better.

[Abhradeep Banerjee]

Jan Hoppmann wrote:So you don't want the odd numbers that are less than 5, but rather less than x, right? That should point you in the right direction

kind of confused now

[fred rosenberger]

My suggestion is always to put in tons of System.out.println() statements to see what your code is doing. Specifically, I would put some in here to see what x and z are at the beginning of each loop.

print out the values each time you think they should change. Print out the values just before any test-condition..i.e. just before each 'while' statement.

I don't think 'z' is what you think it is everywhere...

[Abhradeep Banerjee]

z is the odd numbers

[Junilu Lacar]

step through the loops with paper and pencil, note down the values each time through the loop. You'll see what Fred is trying to tell you.

[Jan Hoppmann]

Abhradeep Banerjee wrote:z is the odd numbers

No. z is exactly one odd number at any given moment, this value is its state. You should check this state at the start and / or end of every loop, simply with System.out.println(z);. You should do the same for x as well.

[Winston Gutkowski]

Abhradeep Banerjee wrote:z is the odd numbers

No it isn't (at least not based on what you wrote).

My advice: Stop guessing, and listen to the advice you've been given (especially fred's). Do some debugging and find out what is going on, because you aren't going to learn anything by simply firing off questions.

Winston

[Abhradeep Banerjee]

maybe this will make it abit clearer of what i understand

package oddnumbers;

public class Oddnumbers {

    public static void main(String[] args) {
        System.out.println("NO" + "     " + "ODD NUMBERS");

        int x = 0;//initializer
        int z = -1; //initializer

        while (x < 15) { //will run as long as the the values of x are less than 15 when it starts the loop

            x = x + 5; // will increment the value of x by 5 everytime  

            System.out.print(x + "      ");// will print a increment of 5 in every loop
            
            while (z < 5) { //start of inner while loop will run as long as the values of z are less than 5
                
                z = z + 2;   // an odd value is calculated in the loop

                System.out.print(z + "  "); // will print out the odd number that is calculated
              
            } // end of inner while loop
            
            System.out.println();// outside the while loop puts the x values on the next line


        }//end of outer while loop  
    }//end main method  
}    //end class  

[Abhradeep Banerjee]

webpage

[Winston Gutkowski]

Abhradeep Banerjee wrote:maybe this will make it abit clearer of what i understand...

Yes, but what you understand doesn't produce what you want, so the question you need to answer is: Why not?

You have been given plenty of advice, but you seem to want someone else to do your work for you.

ShowSomeEffort (←click) or explain what it is you don't understand. It's a requirement of this website.

Winston

[Abhradeep Banerjee]

managed to get it working by using the if statement inside:

package oddnumbers;

public class Oddnumbers {

    public static void main(String[] args) {
        System.out.println("NO" + "     " + "ODD NUMBERS");

        int x = 0;//initializer
        int z = -1; //initializer

        while (x < 15) { //will run as long as the the values of x are less than 15 when it starts the loop

            x = x + 5; // will increment the value of x by 5 everytime  

            System.out.print(x + "      ");// will print a increment of 5 in every loop
            
             if (x==5) {
            while (z < 5) { //start of inner while loop will run as long as the values of z are less than 5
                
                z = z + 2;   // an odd value is calculated in the loop

                System.out.print(z + "  "); // will print out the odd number that is calculated
            }
            }
                    
            if (x==10) {
                z=-1;
            while (z < 9) { //start of inner while loop will run as long as the values of z are less than 5
                
                z = z + 2;   // an odd value is calculated in the loop

                System.out.print(z + "  "); // will print out the odd number that is calculated
            }
            }
                       
            if (x==15) {
                z=-1;
            while (z < 15) { //start of inner while loop will run as long as the values of z are less than 5
                
                z = z + 2;   // an odd value is calculated in the loop

                System.out.print(z + "  "); // will print out the odd number that is calculated
            }
            } // end of inner while loop
            
            System.out.println();// outside the while loop puts the x values on the next line


        }//end of outer while loop  
    }//end main method  
}    //end class  

[Winston Gutkowski]

Abhradeep Banerjee wrote:managed to get it working by using the if statement inside:

OK. Well done. Now I'd suggest that you look back over the advice that you've been given and see if you can do even better.
(Hint: you only need one 'if' statement)

Winston

[Abhradeep Banerjee]

So you don't want the odd numbers that are less than 5, but rather less than x, right? That should point you in the right direction <=== just this statement i dont understand what he means

[Stuart A. Burkett]

Abhradeep Banerjee wrote: So you don't want the odd numbers that are less than 5, but rather less than x, right? That should point you in the right direction <=== just this statement i dont understand what he means

You start off with x set to 5 and print all the odd numbers less than 5
You then set x to 10 and print all the odd numbers less than 10
You then set x to 15 and print all the odd numbers less than 15

Do you see a pattern ?

[Winston Gutkowski]

Abhradeep Banerjee wrote: So you don't want the odd numbers that are less than 5, but rather less than x, right? That should point you in the right direction <=== just this statement i dont understand what he means

Look at your latest code, and specifically at your 3 if statements. What is "the same" about them? They are basically doing the same thing.

Now look at Jan's statement again, and see if it makes more sense.

Winston

[Edit] too slow.