参考：https://github.com/astaxie/build-web-application-with-golang/blob/master/zh/preface.md
【go 入门1 —— 基础语法】主要内容为，基本类型，流程控制，对象接口，方法调用，异常等方面
package mainimport (
"errors"
"fmt"
"runtime"
"time"
)const (
aaaa=1
WHITE= iota
BLACK
HEHE
)var (
AA=1
aa=1
)type(
//method
func1 func(int)int
testInt func(int) bool
// 定义一个 DivideError 结构
DivideError struct {
dividee int
divider int
}
hehe struct {
width ,height int
name string
}
heheqq struct {
hand hehe
hh,ww int
} ha struct {
//匿名为继承
heheqq
aa int
}
Men interface {
say()
}
)
/**Methods Receivers Values
(t T) T and *T
(t *T) *T
如果是值接收者，实体类型的值和指针都可以实现对应的接口；如果是指针接收者，那么只有类型的指针能够实现对应的接口。
**/
func (hh *heheqq) say1(){
fmt.Println(111)
}funcarea1(hh heheqq)int{
return hh.hh*hh.ww
}func (hh *heheqq) area()int{
return hh.hh*hh.ww
}//explain
func main(){
fmt.Println("hello world")
//baseTypeTest
baseTypeTest()
//if for switch
gogoTest()
//methodTest
methodTest()
//error panic recover
errorTest()
//object
objectTest()
//goroutine
gogo()
//channel
channelTest()
//select
selectTest()
//time out
timeoutTest()
}
func timeoutTest(){
c := make(chan int)
o := make(chan bool)
go func() {
for {
select {
case v := <- c:
println(v)
case <-time.After(5*time.Second):
println("timeout")
o <- true
break
//default:
// fmt.Println("heheda")
//
}
}
}()
<- o
}
func selectTest(){
c :=make(chan int)
quit :=make(chan int)
go func() {
for i:=1;
i<10 ;
i++ {
fmt.Println(<-c)
}
quit <-0
}()
fibonacciSelect(c,quit)
}
func fibonacciSelect(c, quit chan int) {
x, y := 1, 1
for {
select {
case c <- x:
x, y = y, x + y
case <-quit:
fmt.Println("quit")
return
}
}
}func channelTest(){
a := []int{7, 2, 8, -9, 4, 0}
//无缓冲 channel，
c := make(chan int)
go sum(a[:len(a)/2],c)
go sum(a[len(a)/2:],c)
//receive from c
x,y := <-c,<-c
fmt.Println(x,y,x+y) //带缓冲
cb :=make(chan int,4)
cb <- 1
cb <- 2
cb <- 1
cb <- 2
fmt.Println(<-cb,<-cb)
fmt.Println(<-cb,<-cb)
//for
ccc :=make(chan int,10)
go fibonacci(cap(ccc),ccc)
for i :=rangeccc{
fmt.Println(i,"-------")
}
}func fibonacci(n int, c chan int) {
x, y := 1, 1
for i := 0;
i < n;
i++ {
c <- x
x, y = y, x + y
}
close(c)
}
func sum(a []int,c chan int){
total :=0
for _,v :=rangea{
total +=v
}
//send to c
c <- total
}
func gogo(){
fmt.Println("goroutine----------------")
fmt.Println("gogogo")
go saysay("hello")
go saysay("he11")
saysay("world")
fmt.Println("hehe")
}func saysay(ss string){ for i := 0;
i < 3;
i++ {
runtime.Gosched()
fmt.Println(ss)
}
}func baseTypeTest(){
fmt.Println("baseTypeTest-----------")
println("枚举",HEHE,WHITE,BLACK)
a :=1
b :="1"
c :=[]int{1,2,3}
ccc :=c[1:2]
var cc =c[1:2]
d :=make(map[string]int)
e :=map[string]int{"11":2,"33":4}
e["11"]=33
ep :=e
app :=&a
*app=11
epp :=&e
//*epp["gg"]=11
fmt.Println(a,b,c,cc,ccc,d,e,ep,app)
fmt.Printf("ip 变量储存的指针地址: %x\n", epp )
}
func gogoTest(){
fmt.Println("process Test---------")
ifa :=1
if ifa>=1 {
fmt.Println("heheha")
}
if ifa=2;
ifa>0{
fmt.Println("hehe",ifa)
} for i :=1;
i<10 ;
i++{
fmt.Println("haha",i)
}
for ifa<10{
ifa+=1
fmt.Println(ifa,"heheda")
funcTest(ifa)
}
a :=[]int{1,2,3}
//traverse
for index,value :=rangea{
fmt.Println(index,value,"=============")
}
for _,value :=rangea{
fmt.Println(value,"=============")
}
for value :=rangea{
fmt.Println(value,"========3333=====")
}
}func methodTest(){
fmt.Println("methodTest------------")
fa,fb,fc :=test(1,2,3)
fmt.Println(fa,fb,fc)
fmt.Println(test1(11,22,33))
test2(1,2,3,4)
//func method
fmt.Println()
fmt.Println(funcmethod(22,funcmethod0))
}func errorTest(){
fmt.Println("------error panic recover-----")
testException()
testCumstomException()
//custom error
fmt.Println("------custom-----")
if result, errorMsg := Divide(100, 10);
errorMsg == "" {
fmt.Println("100/10 = ", result)
}
// 当除数为零的时候会返回错误信息
if _, errorMsg := Divide(100, 0);
errorMsg != "" {
fmt.Println("errorMsg is: ", errorMsg)
}
}
func objectTest(){
fmt.Println("objtest----------")
var obja hehe
fmt.Println(obja)
obja.name="aa"
obja.width=111
obja.height=22
fmt.Println(obja) obbj :=hehe{}
fmt.Println(obbj,"obbj--")
objb :=hehe{1,2,"111"}
fmt.Println("11",objb)
//指针传递
objc :=&objb
objc.height=1
fmt.Println(objc)
fmt.Println(objb)
//深拷贝
objd :=objb
objd.width=33
fmt.Println(objd)
fmt.Println(objb) obje :=hehe{width:1,height:2222}
fmt.Println(obje) gggg :=heheqq{hehe{1,2,"hehe"},3,4}
fmt.Println(gggg)
//deep copy
gg1 :=gggg
gg1.hh=33
fmt.Println(gggg,gg1)
gg2 :=&gggg
gg2.ww=44
fmt.Println(gggg,gg2,*gg2,"pp")
fmt.Println(gggg.area(),area1(gggg)) gg3 :=ha{gggg,1}
fmt.Println(gg3.area())
}// 实现 `error` 接口
func (de *DivideError) Error() string {
strFormat := `
Cannot proceed, the divider is zero.
dividee: %d
divider: 0
`
return fmt.Sprintf(strFormat, de.dividee)
}// 定义 `int` 类型除法运算的函数
func Divide(varDividee int, varDivider int) (result int, errorMsg string) {
if varDivider == 0 {
dData := DivideError{
dividee: varDividee,
divider: varDivider,
}
errorMsg = dData.Error()
return
} else {
return varDividee / varDivider, ""
}}func funcTest(aa int)bool{
fmt.Println("switch test-------------")
a :=aa
switch a {
case 1:
fmt.Println(11)
case 2,3,4:
fmt.Println(a)
case 5:
fmt.Println(a)
fallthrough
default:
fmt.Println("default")
}
return false
}func test(a int ,b int ,c int)(int ,int ,int){
return 1,2,3
}
func test1(a int,b int,c int)(aa int,bb int,cc int){
aa,bb,cc =a,b,c
returnaa,bb,cc
}
//数组遍历
func test2(a ...int){
fmt.Println("traverse----------")
defer fmt.Println("close close close")
defer fmt.Println("close ---- close ----- close")
fmt.Println(a)
for i:=0;
i< len(a);
i++{
fmt.Println(a[i],"----------")
}
for index,value :=rangea{
fmt.Println(index,value,"=============")
}
for _,value :=rangea{
fmt.Println(value,"=============")
}
for value :=rangea{
fmt.Println(value,"=============")
}
}func funcmethod0(a int)int{
return a
}func funcmethod(a int,funct func1)bool{
return a>funct(a)
}
//defer panic recover
// 1、Go中没有 try...catch...finally机制
//2、Go中用 defer panic recover来处理
func testException() {
//func() {}()
defer func() {
err :=recover()
if err !=nil{
fmt.Println("err=",err)
fmt.Println("send")
}
}()
num1 := 10
num2 := 0
res := num1 / num2
fmt.Println("res=",res)
}//自定义异常 recover=catch
func testCumstomException(){
defer func() {
err :=recover()
fmt.Println("catchrecover",err)
}()
err :=readConf("heheda")
if err!=nil {
fmt.Println("catch:",err)
panic(err)
}
}func readConf(name string) error{
if name=="config.ini" {
return nil
}
return errors.New("文件名错误-------")
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