Tour of Go 2.0

For continued

The init and post statements are optional — drop them when you don’t need them.

That leaves just the condition, with the semicolons still there as placeholders. It’s a bit awkward-looking, which is exactly why Go takes this one step further.

main.go ▶ Run in Playground 
package main

import "fmt"

func main() {
	sum := 1
	for ; sum < 1000; {
		sum += sum
	}
	fmt.Println(sum)
}