Golang Basic Data type considerations

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

Basic data types

int type

Different depending on the platform, but even int64 or int32 and int are different and need to be converted

Floating point Type

Default is Float64

Floating-point numbers are best used in the module of the math package, with = = not accurate

" Math " Math. Fdim (Math. Fdim (F1,F2)

BYTE type

One is that byte represents the alias of the Uint8, which represents a byte of the Utf-8
One is that rune represents a single Unicode character UInt32

Array

var a [+byte; [ 2 struct {x, y int32}[]*float64[3] [5int[2] [2] [2] Float64

Creation of Arrays

 for I, V: = range Array {    ... }

traversal of an array

Slice

Two ways to create: Slice on an array and create a new one.

var my Array [ten]int = [ten]int{1234  56789}var my Slice [ ]int = My array[:5]

slicing on an array

My Slice1: = make ([]int5) My Slice2:= make ([]int5)   / /  The first one is Len (), the second is cap ()my Slice3: = []int{1234 5}

directly Create

Append usage of slices

My Slice =//  Note the first one can be a list, but the second must be the corresponding data type, if not used ... Scattered! 

Append Usage

The slice has a copy () method, copy (Slice1, Slice2), and two slices Len can be different. In the case of different lengths, the copy section

Package Mainimport"FMT"func Add (a []int) {a[0] +=1}func AddArray (A [4]int) {a[0] +=1}func Addarray_pointer (a*[4]int) {a[0] +=1}func Main () {varARRA [4]int= [4]int{Ten,2,3,4}//ArrayAddArray (ARRA)//array is a value typeFmt. Println (ARRA)//It doesn't change here .Addarray_pointer (&arra)//Incoming Array pointersFmt. Println (ARRA)//There's been a change.A:= []int{1,2,3,4}//Defining slicesAdd (a)//cannot pass a pointer, and change itselfFmt. Println (a[0])}

! Slice is not a value type, cannot write pointer

Map type

Mymap  = Make (map[string= Make (map[string= map[string ] Person info{  '1234': Person info{"1"  "Jack""101,... "

Create a method

Value, OK: = My map["1234"]if  OK {    //  False if any OK is true}

Take value

Delete (Mymap,"1234")

Delete

    var mymap map[stringint = map[stringint {"123" :456,"233":445}    for i,k:= range Mymap {        fmt. Println (i,k)    }

Traverse

mymap["113"123

Assign Value

Map is not a value type, so pointers cannot be used, and function passing is passing itself