Check if a number is odd

const isOdd = (n) => n % 2 !== 0;

// Or
const isOdd = (n) => !!(n & 1);

// Or
const isOdd = (n) => !Number.isInteger(n / 2);

const isOdd = (n: number): boolean => n % 2 !== 0;

// Or
const isOdd = (n: number): boolean => !!(n & 1);

// Or
const isOdd = (n: number): boolean => !Number.isInteger(n / 2);

isOdd(1); // true
isOdd(2); // false