Three new books, Go Optimizations 101, Go Details & Tips 101 and Go Generics 101 are published now. It is most cost-effective to buy all of them through this book bundle in the Leanpub book store.

How to create slices?

Assume the type of a new created slice is S and s0 is the zero value literal of S.

Way 1 (use composite literals)

	var aSlice = S{} // both length and capacity are zero
	// or
	var aSlice = S{Len - 1: s0} // both length and capacity are Len (a constant)

The capacity of the result slice is not always aligned to a memory class size. (Memory class sizes are mentioned in Go Optimizations 101.)

Way 2 (use the built-in make function):

	var aSlice = make(S, initialLength, capacity)
	// or
	var aSlice = make(S, initialLength) // capacity == initialLength

The capacity of the result slice is not always aligned to a memory class size.

Way 3 (use the built-in append + make functions):

	var aSlice = append(S{}, make(S, initialLength)...)
	// or
	var aSlice = append(S(nil), make(S, initialLength)...)
	// or
	var aSlice = append(S{}, make(S, initialLength, capacity)...)
	// or
	var aSlice = append(S(nil), make(S, initialLength, capacity)...)

With the official toolchain, the capacity of the result slice is aligned to a memory class size.


(more articles ↡)

The Go 101 project is hosted on Github. Welcome to improve Go 101 articles by submitting corrections for all kinds of mistakes, such as typos, grammar errors, wording inaccuracies, description flaws, code bugs and broken links.

If you would like to learn some Go details and facts every serveral days, please follow Go 101's official Twitter account @zigo_101.

Tapir, the author of Go 101, has been on writing the Go 101 series books and maintaining the go101.org website since 2016 July. New contents will be continually added to the book and the website from time to time. Tapir is also an indie game developer. You can also support Go 101 by playing Tapir's games (made for both Android and iPhone/iPad):
Individual donations via PayPal are also welcome.

Articles in this book: