Go language string data type format

This is a creation in Article, where the information may have evolved or changed.

In the go language, define the following string:
var ss string = "12345"

For a programmer who is familiar with C + +, it is immediately thought of what the string is, how much space it is, how memory is allocated, and so on, so let's analyze the problem.

The go language string is a data type that occupies 16 bytes of space, the first 8 bytes is a pointer to the address of the string value, the last eight bytes is an integer, and the length of the string is identified; note that the inside of the go language string does not 0 ' ends with a length field to represent the length of the string.

type mystr struct {    strbuf uintptr;    strlen uint64;}

The above is the type definition of string. Here's a code to verify the problem:

  Package Mainimport ("FMT" "unsafe"//"reflect") type mystr struct {strbuf uintptr; Strlen UInt64;} Func printmemory (P uintptr, size int) {FMT. Printf ("[0x%16x:%2d] =", p, size) for I: = 0; i < size; i++ {p1: = unsafe. Pointer (p + uintptr (i)) P2: = (*byte) (unsafe. Pointer (p1)) fmt. Printf ("%x", *P2)} fmt.    Printf ("\ n")}func main () {var ss string = "12345"; Fmt. Printf ("string=%v\n", ss) Fmt. Printf ("length=%v\n", Len (ss)) Fmt. Printf ("size=%v\n", unsafe. Sizeof (ss)) Fmt. Printf ("address=%v\n", &ss) ptr: = unsafe. Pointer (&SS)//value: = reflect. ValueOf (&SS)//fmt. Println (reflect. TypeOf (value), reflect. ValueOf (value). Kind ())//ptr1: = value.    Pointer () Ptr1: = UIntPtr (PTR) printmemory (PTR1, 16); PTR2: = (* mystr) (PTR) fmt. Printf ("mystr.strbuf=%x\n", Ptr2.strbuf) fmt. Printf ("mystr.strlen=%v\n", Ptr2.strlen) printmemory (Ptr2.strbuf, Len (ss) +1);}  

The results of the implementation are as follows:

$ go build main.go && ./main string=12345length=5size=16address=0xc42000e2c0[0x      c42000e2c0:16] = f1 70 4a 0 0 0 0 0 5 0 0 0 0 0 0 0mystr.strbuf=4a70f1mystr.strlen=5[0x          4a70f1: 6] = 31 32 33 34 35 31

We see the memory structure of the string, which contains a pointer to the string data, and an integer value that identifies the length of the string, and the end of the string does not have a ' s ' to identify, in the example above is a random value (0x31).

Pointer operations on the GO language

The only difference between a go language pointer and a C + + pointer is that the go language does not allow arithmetic operations on pointers (+ 、-、 + + 、--).

However, go provides a set of underlying libraries reflect and unsafe, which can convert any go pointer to a value of type uintptr, and then perform arithmetic operations on the pointer as in C + + and finally revert to the Go type. So from this point of view, the go pointer can also be used as a C + + pointer, but will be compared around, it also requires the user to understand, if you really want to use the pointer, then please remember the consequences of self-esteem.

Here is an example of a Go language pointer operation:
Https://play.golang.org/p/z_GMnh38Z1