How do you check if a number is even in Cairo?

from starkware.cairo.common.math import unsigned_div_rem



func is_even{range_check_ptr}(x) -> (res):

let (_, is_odd) = unsigned_div_rem(x, 2)

return (res=1 - is_odd)

end

ㅤ This answer was originally posted on Triality

You can use bitwise operations to check this

bitwise_and(number, 1) == 0 and #where number is your variable you are testing if even

This is a code snippet to illustrate the point well

%builtins bitwise

from starkware.cairo.common.bitwise import bitwise_and

from starkware.cairo.common.cairo_builtins import BitwiseBuiltin



func main{bitwise_ptr : BitwiseBuiltin*}():

let (temp) = bitwise_and(3, 1)

assert temp = 1

let (temp) = bitwise_and(4, 1)

assert temp = 0

return ()

end

ㅤ This answer was originally posted on Triality