What does the % operator do in Ruby in N % 2?

Question

if counter % 2 == 1 I am trying to decode this line - it\'s a Rails project and I am trying to figure out what the % does in this if statement.

Answer 1

Also keep in mind that, Ruby's definition of the modulo (%) operator differs from that of C and Java. In Ruby, -7%3 is 2. In C and Java, the result is -1 instead. In Ruby, the sign of the result (for % operator) is always the same as the sign of the second operand.

Answer 2

In answer to the question "What does the % symbol do or mean in Ruby?" It is:

1) The modulo binary operator (as has been mentioned)

17 % 10 #=> 7 

2) The alternative string delimiter token

%Q{hello world} #=> "hello world"
%Q(hello world) #=> "hello world"
%Q[hello world] #=> "hello world"
%Q!hello world! #=> "hello world"
# i.e. choose your own bracket pair
%q(hello world) #=> 'hello world'
%x(pwd)         #=> `pwd`
%r(.*)          #=> /.*/

3) The string format operator (shorthand for Kernel::sprintf)

"05d" % 123 #=> "00123"

Answer 3

That's the modulo operator. It gives the remainder when counter is divided by 2.

For example:
3 % 2 == 1  
2 % 2 == 0