A SMALL QUESTION. AN ENTIRE WEBSITE.
How do I calculate if an integer is odd?
Divide it by two. If there’s one left over, it’s odd. That’s the answer. We made a whole website anyway.
Give me the explanation ↗For the curious, the coders,
and the spectacularly overthinking.
n % 2 !== 0In JavaScript, for a validated integer.
Mind the edge cases ↗
PICK YOUR LEVEL OF CURIOSITY
There’s a little
more to odd.
The basics are simple. The details are interesting.
Choose your rabbit hole.
Number basics
Zero, negative numbers, very big integers. Start with the rules, then find the exceptions that aren’t exceptions.
12 guidesWrite the code
Working examples in JavaScript, Python, SQL, spreadsheets, and more. Including the edge cases.
12 guidesThe Jev lab
What happens when you ask an AI to do arithmetic? API guides, a very odd npm package, and the actual benchmarks.
12 guidesGOOD PLACES TO START
Oddly useful reading.
Is zero odd or even?
Zero is even because 0 = 2 × 0. See the definition, the number-line pattern, and the difference between dividing zero and dividing by zero.
Check whether a number is odd in JavaScript
Use a safe-integer guard and remainder to check odd numbers in JavaScript, including negatives, zero, invalid inputs, and precision limits.
What is Jev? Typed AI decisions, explained
An independent introduction to TypeSafe’s Jev model, typed questions, and the deliberately impractical is-jodd example.
Can negative numbers be odd?
Negative integers can be odd or even. Learn why sign does not change parity and why JavaScript’s negative remainder needs a careful test.
Check odd BigInt values without losing decimal digits
Validate signed decimal strings and check JavaScript BigInt parity without converting through Number or accepting malformed text.
is-jodd vs is-jeven: smaller runtime, no proven speed win
Compare the actual is-jodd 1.0.0 and is-jeven 1.0.0 interfaces, package sizes, and live benchmark results.
ONE LAST THING