kata.js

const opposite = n => n === 0 ? 0 : n * -1;

console.log(opposite(1)); // -1


console.log(opposite(0)); // 0


console.log(opposite(4.25)); // -4.25


console.log(opposite(3.3333333)); // -3.3333333


console.log(opposite(-12525220.3325)); // 12525220.3325


console.log(opposite(-5)); // 5