A LIBRARY FOR A VERY SPECIFIC QUESTION

The whole odd library.

Every guide, every edge case, every unnecessarily thorough experiment. Find the answer you came for, or a question you didn’t know you had.

36 guides

Write the code01

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.

3 min read
Write the code02

Check odd numbers in TypeScript with runtime validation

Build a TypeScript odd-number check that narrows unknown input, validates safe integers, and distinguishes invalid data from an even result.

3 min read
Write the code03

Check whether an integer is odd in Python

Write a Python odd-number helper with explicit integer validation, correct negative-number behavior, and a clear policy for booleans and large integers.

3 min read
Write the code04

Check odd numbers in Java, including negative values

Use a long remainder check in Java, parse text with Long.parseLong, and avoid negative-number and minimum-value mistakes.

3 min read
Write the code05

Check odd numbers in C# without losing input errors

Check a C# long for oddness, parse signed decimal text safely, and keep invalid or missing input separate from even numbers.

3 min read
Write the code06

Check whether an integer is odd in Go

Use an int64 remainder check in Go, parse decimal text with strconv, and handle architecture-dependent integers and parse errors explicitly.

3 min read
Write the code07

Check odd numbers in Rust with explicit parsing errors

Check i64 parity in Rust, propagate ParseIntError with Result, and cover negative integers, whitespace, range limits, and minimum values.

3 min read
Write the code08

Check odd integers in PHP without silent coercion

Use is_int and remainder in PHP to reject strings, fractions, and booleans before checking signed integer parity.

3 min read
Write the code09

Find odd numbers in SQL using PostgreSQL

Use PostgreSQL mod or % for integer parity, handle NULL deliberately, and distinguish odd ID values from alternating query rows.

3 min read
Write the code10

Check odd numbers in Excel without accepting fractions

Use Excel ISODD for integer cells, add a whole-number guard, and keep blanks, text, errors, and fractions distinct from even values.

2 min read
Write the code11

Check odd numbers in Google Sheets with clear validation

Build a Google Sheets parity formula that rejects fractions and text, then highlight odd integer rows without hiding invalid entries.

2 min read
Write the code12

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.

3 min read
The Jev lab13

What is Jev? Typed AI decisions, explained

An independent introduction to TypeSafe’s Jev model, typed questions, and the deliberately impractical is-jodd example.

3 min read
The Jev lab14

Jev API quickstart with JavaScript fetch

Build a small Jev request with native fetch, inspect a Noul answer, and keep credentials on the server.

3 min read
The Jev lab15

Jev Noul questions: turn a probability into a boolean

Understand a Jev Noul result, validate its shape, and make the boolean threshold explicit in your code.

3 min read
The Jev lab16

Jev Choice vs Noul: pick the answer shape your code needs

Compare categorical Choice answers with Noul yes/no judgments using is-jeven and is-jodd as a concrete example.

3 min read
The Jev lab17

Getting started with is-jodd: API, requirements, and the joke

Read the is-jodd contract before using it: Node 24+, API credentials, safe integers, async results, and its custom restrictive license.

3 min read
The Jev lab18

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.

2 min read
The Jev lab19

Jev parity benchmarks: what our 44 requests actually showed

Read the full context behind is-jodd’s live benchmark: paired inputs, warmups, accuracy checks, uncertainty, and the separate transport pilot.

2 min read
The Jev lab20

Jev confidence vs correctness: what a strong answer proves

Separate Jev’s reported uncertainty, your decision threshold, and correctness measured against known answers.

3 min read
The Jev lab21

Jev API errors and timeouts: keep failures separate from false

Handle missing credentials, HTTP failures, cancellation, and invalid Jev answers without turning them into ordinary parity results.

3 min read
The Jev lab22

Await before negating: the is-jeven Promise trap

Why !isEven(n) is not an oddness check, and how to negate an async boolean without hiding errors.

2 min read
The Jev lab23

Smaller Jev requests: what saved 51 JSON bytes

Examine is-jodd’s compact state and Noul question, then distinguish request bytes, module size, archive size, and live latency.

3 min read
The Jev lab24

When not to use AI for math: the is-jodd example

Use exact arithmetic for exact questions, and keep probabilistic interpretation outside the calculation itself.

3 min read
Number basics25

How to tell if a number is odd

Check an integer’s last digit, divide it by two, or write it as 2k + 1. Learn three exact methods with examples and input tips.

2 min read
Number basics26

What is an odd integer?

Understand the definition n = 2k + 1, including negative odd integers, equivalent formulas, and why integers cannot be both odd and even.

2 min read
Number basics27

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.

2 min read
Number basics28

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.

2 min read
Number basics29

Are decimals odd or even?

Non-integer decimals are neither odd nor even, but 3.0 is an odd integer value. Separate mathematical value from decimal notation and input syntax.

2 min read
Number basics30

Odd and even number rules

Predict parity for addition, subtraction, multiplication, and powers. See the algebra behind the rules and why division needs more information.

3 min read
Number basics31

The last-digit test for odd numbers

Learn why decimal integers ending in 1, 3, 5, 7, or 9 are odd, including the proof, negative numbers, leading zeros, and common traps.

2 min read
Number basics32

Modulo versus remainder when testing odd numbers

Understand why −7 modulo 2 is 1 while JavaScript returns −1 for -7 % 2, and write an odd-number test that handles both signs.

2 min read
Number basics33

Odd numbers in binary

An integer’s last binary digit determines whether its value is odd. Learn the place-value proof and avoid confusing value parity with bit-count parity.

2 min read
Number basics34

How to check the parity of a large integer

Keep large integers exact with digit strings or BigInt. Learn why converting 9007199254740993 to a JavaScript Number can reverse the answer.

2 min read
Number basics35

Odd numbers and prime numbers are different

All primes greater than two are odd, but many odd numbers are composite. Understand the distinction with examples, proofs, and the special case of one.

3 min read
Number basics36

Common odd-number mistakes and how to avoid them

Avoid the usual parity traps: zero, negative remainders, decimals, rounded integers, prime numbers, and confusing a number’s value with its spelling.

3 min read