There are forms with different behavior when used in expressions:
let x = 5
console.log(x++) // 5 (returns old value, then increments)
console.log(x) // 6
let y = 5
console.log(++y) // 6 (increments first, then returns)
console.log(y) // 6
Post-increment (x++) returns the old value. Pre-increment (++x) returns the new value. In standalone statements like x++, there's no difference.