Could anyone explain this ? Help me to understand this statement

Question

This code is c++ and it will display a Christmas Tree
I just copied from google
/* ---------------------------------------- */
#include <iostream>
using namespace std;

int main() {
int n = 5;

for( int i = 1; i <= n; i++ ) {
for( int k = i; k <= n - 1; k++ )
{
cout << " ";
}
for( int j = 1; j <= i; j++ )
{
if( j % 3 == 0 )
{
cout << "o ";
}
else if( j % 3 == 1 ){
cout << "* ";
}
else
{
cout << "# ";
}
}
cout << endl;
}
}
/* ---------------------------------------- */
I am confuse with this statement ( j % 3 == 0 )
and ( j % 3 == 1 ) .

I understand the j (var) it will loop and count 1 2 3 4 5
but the following code I dont really understand
the % 3 == 0 and % 3 == 1 .

Could anyone help me to understand this and give me some explaination bout this.

Answer 1

As Androidus told, % is modulus operator. It returns the remainder when two numbers are divided unequally. If the two numbers are divided equally it returns 0. For example:
11 % 2 = 1
6 % 3 = 0
6 % 10 = 6
-4 % 2 = 0
-7 % 9 = - 7

Answer 2

The '%' sign is called the modulo. It returns the rest of the division between 2 numbers. For example :
- 4%3=1
- 5%3=2
- 6%3=0

Answer 3

the display of the loop without number
*
* #
* # o
* # o *
* # o * #
/* ------------------------------------------------ */
I test the code many times the ( j % 3 == 0 ) statement, it has a { cout << "o "; } so I put the variable ( j ) in the { cout << j << "o "; } to identify where he is. And then I run the program it displays like this, there is a number three ( 3 ) in the printed text ( o ) so it means that he is placed on number three ( 3 ) in loop 1 2 3 4 5.

*
* #
* # 3o
* # 3o *
* # 3o * #

/* ------------------------------------------------ */

I put the variable in every printing text { cout }
to identify each counting number of the loop
and it will look like this

1*
1* 2#
1* 2# 3o
1* 2# 3o 4*
1* 2# 3o 4* 5#

/* ------------------------------------------------ */

( j % 3 == 0 )
lets say the ( j ) there is 5, then ( % ) modulo is 3, so the answer is 2 .
( 5 % 3 == 0 )
5 % 3 = 2
( 2 == 0 )

Im wondering why it is placed in 3 and not in 2
in the loop of 1 2 3 4 5.

the answer 2 is followed by == 0 .
( 2 == 0 )
2 is equal to 0
so 2 will become 0 ?