Tour of Go 2.0

Slice defaults

When slicing, you can omit either bound and Go fills in the default: 0 for the low end, and the slice’s length for the high end.

So for a 10-element array, all four of these mean the same thing:

a[0:10]
a[:10]
a[0:]
a[:]

Try it: Rewrite the slice operations in the example using different combinations of defaults.

main.go ▶ Run in Playground 
package main

import "fmt"

func main() {
	s := []int{2, 3, 5, 7, 11, 13}

	s = s[1:4]
	fmt.Println(s)

	s = s[:2]
	fmt.Println(s)

	s = s[1:]
	fmt.Println(s)
}