negate

const isEven = (value: number) => value % 2 === 0;

const isOdd = negate(isEven);

console.log(isOdd(3));
// true

console.log(isOdd(4));
// false

const isEmpty = (value: string) => value.length === 0;

const isNotEmpty = negate(isEmpty);

console.log(isNotEmpty("CyrefJS"));
// true

console.log(isNotEmpty(""));
// false

const isGreater = (a: number, b: number) => a > b;

const isNotGreater = negate(isGreater);

console.log(isNotGreater(5, 3));
// false

console.log(isNotGreater(2, 4));
// true

const isEven = (value: number) => value % 2 === 0;

const isOdd = negate(isEven);

const numbers = [1, 2, 3, 4, 5, 6];

const result = numbers.filter(isOdd);

console.log(result);
// [1, 3, 5]

const isPositive = (value: number) => value > 0;

const isNotPositive = negate(isPositive);

console.log(isPositive(5));
// true

console.log(isNotPositive(5));
// false