一元减（-）

const x = 4;
const y = -x;

console.log(y);
// Expected output: -4

const a = "4";
const b = -a;

console.log(b);
// Expected output: -4

-x

const x = 3;
const y = -x;

// y = -3
// x = 3

const x = "4";
const y = -x;

// y = -4