this post was submitted on 07 Dec 2023
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God I wish there was an easier way to do this (programming.dev)
submitted 11 months ago* (last edited 11 months ago) by andioop@programming.dev to c/programming_horror@programming.dev
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[–] recursive_recursion@programming.dev 9 points 11 months ago* (last edited 11 months ago) (7 children)

modulo

pseudocode:

if number % 2 == 0
  return "number is even" (is_num_even = 1 or true)
else
  return "number is odd" (is_num_even = 0 or false)

plus you'd want an input validation beforehand

[–] mac@programming.dev 23 points 11 months ago* (last edited 11 months ago) (2 children)

who needs modulo when you can get less characters out of

while (number > 1) {
  number -= 2;
}
return number;

very efficient

edit: or theres the trusty iseven api

[–] nullPointer@programming.dev 9 points 11 months ago (2 children)

here is somewhat less:

return (number % 2) == 0;

[–] pivot_root@lemmy.world 10 points 11 months ago (1 children)

return !(number & 1);

[–] venoft@lemmy.world 8 points 11 months ago* (last edited 11 months ago) (1 children)

This is the way. Modulo takes too long to compute, bitwise compare should be a lot faster.

return !(number & 0x1);
[–] recursive_recursion@programming.dev 5 points 11 months ago* (last edited 11 months ago)

oh shit yo

this comment chain is pretty awesome, I learned a lot from this thanks!

[–] huf@hexbear.net 4 points 11 months ago

just check the last bit jesus christ, what is it with these expensive modulo operations?!

return !(n&1);

[–] perviouslyiner@lemm.ee 2 points 11 months ago (1 children)

are the negative numbers all even?

[–] Vex_Detrause@lemmy.ca 4 points 11 months ago (1 children) 
#You are an input. You have value! You matter!
if number % 2 == 0
  return "number is even" (is_num_even = 1 or true)
else
  return "number is odd" (is_num_even = 0 or false)

Am I doing it right? /S.

[–] PoolloverNathan@programming.dev 5 points 11 months ago

Don't put nbsps in code blocks, they show up literally.

[–] misophist@lemmy.world 3 points 11 months ago

Name doesn't check out.

[–] comrade_pibb@hexbear.net 2 points 11 months ago

John carmak posting

[–] TankieTanuki@hexbear.net 2 points 11 months ago

are u a wizard?

[–] RandomVideos@programming.dev 2 points 11 months ago

This code is terrible. If you input 10.66 it returns "number is odd

It should be:

if number % 2 == 0
  return "number is even" (is_num_even = 1 or true)
else
  return "number is not even" (is_num_even = 0 or false)