java program for print all numbers between -100 to 100 divisible by 3

Question

I tried this many times, but if anyone can help with this solution I would be grateful.

There is my code, any other versions?

int n=201;
int []array = new int[n];
int j=0;

for (int i = -100;i <= 100; i++)
{
    if (i % 3 != 0)
    {
        array[j] = i;
        j++;
    }
}
for (int i = 0;i < j;i++)
{
    System.out.println(array[i]);
}

Answer 1

There's no need to store the numbers since you want just to print them:

for (int i = -100;i <= 100; i++)
  if (i % 3 == 0)
    System.out.println(i);

If you want to save such values in some collection, have a look at ArrayList<T> (instead of array):

ArrayList<Integer> list = new ArrayList<Integer>();
        
for (int i = -100;i <= 100; i++)
  if (i % 3 == 0)
    list.add(i);
            
for (int item : list)    
  System.out.println(item);

Answer 2

java program for print all numbers between -100 to 100 divisible by 3

You don't need a list or array. Just print the numbers.

Using the fact that that integer division drops the fraction (100/3 = 33) and that 33*3 = 99 you can determine the starting and ending number divisible by 3 . Then just increment the counter by 3 .

int start = -(100/3)*3;// first number divisible by three greater than -100.
int end  = (100/3)*3;  // last number divisible by three less than 100.

for(int i = start; i <= end; i+=3) {
   System.out.println(i);
}

Answer 3

You can use the Stream API to print all numbers between -100 to 100 divisible by 3.

Like this...

IntStream.rangeClosed(-100, 100)
         .filter((item) -> item % 3 == 0)
         .forEach(System.out::println);

The rangeClosed() method takes both the arguments and generates a Stream containing a sequence of numbers from -100 to 100 both inclusive .