GoLang Notes

Package

package math/rand 的名字就是 rand.
Exported name first letter is capital letter e.g. math.Pi.

Functions

when defining function, types comes after the name
you can also write x, y int
a function can return multi type value

func swap(x, y string) (string, string) {
	return y, x
}

func main() {
	a, b := swap("hello", "world")
	fmt.Println(a, b)
}

you can use nake return statement, but you should avoid doing it.

func split(sum int) (x, y int) {
	x = sum * 4 / 9
	y = sum - x
	return
}

Types

all the types are

bool

string

int  int8  int16  int32  int64
uint uint8 uint16 uint32 uint64 uintptr

byte // alias for uint8

rune // alias for int32
     // represents a Unicode code point

float32 float64

complex64 complex128

you should define a variable with its type, otherwise you should intialize it

var c, python, java = true, false, "no!"

Inside a function, the := short assignment statement can be used in place of a var declaration with implicit type.
use simple function for type convention

var i int = 42
var f float64 = float64(i)
var u uint = uint(f)

i := 42
f := float64(i)
u := uint(f)

＊ defer can delay a function until other excuted, it follows a last-in-first-out order.

Some struct

Pointer

func main() {
	i, j := 42, 2701

	p := &i         // point to i
	fmt.Println(*p) // read i through the pointer
	*p = 21         // set i through the pointer
	fmt.Println(i)  // see the new value of i

	p = &j         // point to j
	*p = *p / 37   // divide j through the pointer
	fmt.Println(j) // see the new value of j
}

output is : 42, 21, 73

==== Struct