[go-nuts] Best way to convert byte array (not slice) to string?

Create the slice inline:

src := [10]byte{'h', 'e', 'l', 'l', 'o'}
str := string(src[:]) // slice the array from beginning to end

-Daniel

Thanks. That's pretty interesting. So Go auto-magically creates a
slice for you if you index an array that way?

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When you slice an array you get a slice of that array, if you slice a slice
you get a slice of that slice.
http://golang.org/doc/effective_go.html#slices

You can slice strings too and you'll get a string that is a slice of the
original string.

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The only "auto-magical" part would be the automatic determination of the
source array's (or source slice's) bounds. The manual way of doing the same
thing would be:

slc := src[0:len(src)]

Otherwise, it's just Go's basic slicing operation. It's pretty much the
same syntax that Python uses for slicing lists (sans negative indices).

-Daniel

Though with the important difference that Go slices can't take Python's
extended slice form(s), and cannot take a 'step', and while Python always
semantically copies when a slice occurs, Go never does.

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I'm now having an issue with len(). It still returns the size of the
underlying array, not what I would consider the "correct" length of
the string (number of chars until null):
http://play.golang.org/p/x3Xz-4yRkZ

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http://play.golang.org/p/o3nKoXs3BL, maybe ?

you can use bytes.IndexByte or strings.Index for this task.

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It's not too much of a magic trick, considering that slices are just a
struct roughly like:

struct {
data unsafe.Pointer,
len, cap int
}

Due to this, an "automagic slice" of a 20mb string is exactly as cheap as
an automagic slice of a 20 byte string, since no copies are involved.
Go is not C. A "string" in Go is like a slice header (that struct above),
except it does not have a cap, and very specifically, a Go string
consisting of 20 null bytes still has a "string length" of 20. In Go, there
is no '\0': it's '\x00', since '\0' is not all that useful here. All this
means that no matter the length of your string, you always have length
information immediately available for the low cost of the size of an int
(4-8 bytes), as opposed to regular C strings, which have linear-time length
determinations and are susceptible to a large number of problems.

That said, len is doing precisely what it's defined to do. To graft C-like
behavior on top of Go strings, you may
do: http://play.golang.org/p/g46t7xtb_1

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