go语言细节

 1 package main
 2 
 3 import (
 4     "fmt"
 5 )
 6 
 7 func main() {
 8     //数组
 9     a1 := [3]int{1, 2, 3}
10     a2 := a1
11     a2[0] = 2 
12     fmt.Println(a1) //print: 1 2 3
13     fmt.Println(a2) //print: 2 2 3
14     // 字符串
15     s1 := "123"
16     s2 := s1
17     s2 = "223"
18     fmt.Println(s1) //print 123
19     fmt.Println(s2) //print 223
20     // 切片
21     slice1 := []int{1, 2, 3}
22     slice2 := slice1
23     slice2[0] = 2 
24     fmt.Println(slice1) //print 2 2 3
25     fmt.Println(slice2) //print 2 2 3
26     // map
27     m1 := make(map[int]string)
28     m1[1] = "1" 
29     m2 := m1
30     m2[1] = "2" 
31     fmt.Println(m1) //print 1:2
32     fmt.Println(m2) //print 1:2
33     // chan
34     c1 := make(chan bool)
35     c2 := c1
36     go func() {
37         v := <-c2
38         fmt.Println(v) //print true
39     }() 
40     c1 <- true
41 }

 1 package main
 2 
 3 import (
 4     "fmt"
 5 )
 6 
 7 func main() {
 8     s := "hello world"
 9     var i interface{} = s 
10 
11     switch i.(type) {
12     case []byte:
13         fmt.Println("string type is []byte")
14     case []rune:
15         fmt.Println("string type is []rune")
16     case []int8:
17         fmt.Println("string type is []int8")
18     }   
19 
20     slice := []byte{1, 2}
21     i = slice
22     switch i.(type) {
23     case []uint8:
24         fmt.Println("byte is uint8")//print 
25     }   
26 }

 1 package main
 2 
 3 import (
 4     "fmt"
 5 )
 6 
 7 func trueNil() interface{} {
 8     return nil 
 9 }
10 
11 func falseNil() interface{} {
12     var ret *int = nil // 此nil带有类型
13     return ret 
14 }
15 func main() {
16     if trueNil() == nil {
17         fmt.Println("trueNil") //print trueNil
18     }   
19 
20     if falseNil() == nil {
21         fmt.Println("falseNil") //no print
22     }   
23 }