God I wish there was an easier way to do this

You could do this in one line...

By removing all the linebreaks.

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i think it should one giant ternary expression composition
I love this thread 🫠

Of course there's an easier way. Just integrate the state of the art API dedicated for this exact problem. https://isevenapi.xyz/

This is confusing. I'm already using the iSeven API to determine if a number is 7. I'm getting a namespace collision error when I try to load this new API. Bug report filed.

I know how to fix this!

bool IsEven(int number) {
    bool even = true;
    for (int i = 0; i &lt; number; ++i) {
        if (even == true) {
            even = false;
        }
        else if (even == false) {
            even = true;
        }
        else {
            throw RuntimeException("Could not determine whether even is true or false.");
        }
    }

    if (even == true) {
        return even ? true : false;
    }
    else if (even == false) {
        return (!even) ? false : true;
    }
    else {
        throw RuntimeException("Could not determine whether even is true or false.");
    }
}

Have you tried seeing if the recursive approach runs faster?
- I know an even better way. We can make it run in O(1) by using a lookup table. We only need to store 2^64 booleans in an array first.

Back when I was learning programming a lot of lessons would make you do something like this, and then show you the real way to do it in the next lesson. My reaction was always "why didn't you lead with this?".

You must see the pain before you confront it.
Because the point of the lesson is to demonstrate that you can solve the same problem multiple ways where some paths are more efficient than others.

Bad programmers are the ones that find the first solution and implement it no matter how inefficient it is.

Good programmers spend time on figuring out the solution with the least amount broken or inefficient code. You don’t learn this by jumping straight to the best answer every time.

My solution in perl back in the day when I was a teenage hobbyist who didn't know about the modulus operator: Divide by 2 and use regex to check for a decimal point.

if ($num / 2 =~ /\./) { return "odd" }
else { return "even" }

Divide by 2 and check for a decimal point.

I mean, it ain't wrong.
- You know, I was going to let this slide under the notion that we're just ignoring the limited precision of floating point numbers... But then I thought about it and it's probably not right even if you were computing with real numbers! The decimal representation of real numbers isn't unique, so this could tell me that "2 = 1.9999..." is odd. Maybe your string coercion is guaranteed to return the finite decimal representation, but I think that would be undecidable.

Programming humor on reddit used to be excellent bits like this but then it devolved into new learners jumping straight to the irony they didn't understand and flooded the sub with nonsense.

I miss these bits.

btw it does get easier

import math
def is_even(num):
    if num in [i for i in range(1000) if float(i)/2.0 == math.floor(float(i)/2.0)]:
        print("true")
    else:
        print("false")

Obviously one would need to increase the range for bigger numbers but this code is optimized.

for i in itertools.count(): ... will count to infinity.

Better make it into a dictionary so it's O(1) complexity instead of O(n) while you're at it.

def is_even(n):
    match n:
        case 1:
            return False
        case 0:
            return True
        # fix No1
        case n &lt; 0:
            return is_even(-1*n)
        case _:
            return is_even(n-2)

Python added match/case?! Bunch of mypy issues have been closed too. Maybe its time to dust off some old projects.
- It was added in 3.10 and is surprisingly complete. The tutorial pep is a good starting point to see what it can accomplish
Well... At least it's tail recursive.
What if the input is negative
- Fixed!

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

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
- here is somewhat less:
  
  return (number % 2) == 0;
- are the negative numbers all even?
🤦
#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.
- Don't put nbsps in code blocks, they show up literally.
Name doesn't check out.
John carmak posting
are u a wizard?
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)

Well, there is. Write an algorithm that generates all the lines.. /s

This could be optimized by using a recursive function.

This could be made more servicavle by using a switch case
what's the big O of an even number

there is!

I would replace each if/else with a while.

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God, this must go on for, like, twenty or so lines.

Source tweet

...btw a switch statement is better in this case(get it?)

I would love it if someone edited this example and posted it with two statements near the end that are reversed, implying inconsistent behaviour at random in the list ahead, seemingly making this solution less inefficient.

Randomly return true or false. See if anyone notices.

Modulo

You joke, but I've seen a programming language that didn't have a loop, and if you copied a line of text and pasted it in a text editor, JSON would come out...

The editor could barely handle 400+ lines because it probably converted the text to JSON, added a letter and converted it back to JSON... Per inserted symbol...