Golang Study Notes

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

Golang Study Notes

Basic syntax

Keywords (key word) && variables

• The

• Keyword
  Golang has only 25 keywords, as follows:

   import  type  return  const  if  else  for  range  break  select  default< /span> goto  switch  fallthrough  func  interface  case  chan  continue  defer  go  map struct  package   

• Variable declaration && Initialization && Assignment
  The Golang variable declaration way differs from the C + + system language Obviously, to the Golang this kind of declaration way has discussed why the Go language put the type behind?
  Golang introduces the var keyword, and type information is placed after the variable name.
  "Go
  var n int//define an int variable
  var f float32
  var str string//define a string variable
  var arr [10]int//array
  var m map[int]int//Map
  var p *int//pointer

var n int = 10//define and initialize
var n = 10
N: = 10//Effect sample, can be automatically pushed to n type

n = 100//Assignment
N2: = N//define and initialize

......

由上面示例可以看出，golang语句不需要分号作结束符，而且定义一个变量是被初始化的一般默认值是`0`，而指针是`nil`，`string`是`""`。

Package Main

Import "FMT"

Func Main () {
var n int
Fmt. PRINTLN ("int:", N)
var f float32
Fmt. Println ("float:", f)
var str string
Fmt. Println ("string:", str)
var arr [10]int
Fmt. Printf ("array:")
For I: = 0; I < Len (arr); i++ {
Fmt. Printf ("%d", Arr[i])
}
Fmt. Println ()
var p int
Fmt. PRINTLN ("int:", p)
}
/
Output
int:0
float:0
String
array:0 0 0 0 0 0 0 0 0 0
Int:
*/
```

Types (Type)

Built-in base type in Golang

• Boolean
• int8, Byte, int16, int, uint, uintptr
• float32, float64
• Complex64, complex128
• String
• Rune
• Error

Composite type

• Arrays (Array)
• Dictionary (map)
• Slicing (slice)
• struct (struct)
• Channel (Chan)
• Interface (interface)
• Pointer (pointer)
• References (Reference)

Process controls (flow control)

• Conditional statements
  If Else
• SELECT statement
  Switch Case Select
• Looping statements
  For range
• Jump statement
  Goto

Functions (function) && packages (package)

• function definition
  "Go
  Func Func_name () {

}
```

• Function call
• Indeterminate parameters
• Multiple return values
• Anonymous functions && Closures
• Package Management

Object oriented

• Methods (method)
• Anonymous fields
• Interface (interface)