Challenge 2 — Solution

Task: Write a for loop used as a while loop: starting with
balance := 100, keep subtracting 30 and printing the new balance
each time, stopping (using the condition, not break) once balance
would go below 0.

package main

import "fmt"

func main() {
	balance := 100

	for balance >= 0 {
		fmt.Println(balance)
		balance -= 30
	}
}


Expected output:

100
70
40
10

Notes:
- for balance >= 0 has no init or post clause — just a condition —
  which is exactly how Go writes a while loop; there is no separate
  while keyword.
- The loop stops naturally once balance becomes -20 (after the 4th
  subtraction), since -20 >= 0 is false — no break statement was
  needed because the condition itself does the job.
- balance -= 30 is the same compound-assignment shorthand available
  in JavaScript, just without semicolons needed at the end of the
  line.