go学习笔记

go的安装，IDE使用的jetBrains的Gogland，全部安装完后在IDE中的File中设置setting配置好goroot和gopath；

使用的书籍是《Go语言程序设计》，在windows的cmd中运行；

第一个例子

package main

import(
       "fmt"
       "os"
       "strings"
)

func main()  {
       who :="world!"
       if len(os.Args)>1{
              who=strings.Join(os.Args[1:],"")
       }
       fmt.Println("Helllo",who)
}

 

 

第二个例子

package main

import (
       "fmt"
       "os"
       "path/filepath"
       "log"
)

var bigDigits=[][]string{
       {"  000  "},
       {" 1 "},
       {" 2 "},
       {" 3 "},
       {" 4 "},
       {" 5 "},
       {" 6 "},
       {" 7 "},
       {" 8 "},
       {" 9 "},
}

func main()  {
       if len(os.Args)==1{
              fmt.Printf("usage:%s<whole-number>\n",filepath.Base(os.Args[0]))
              os.Exit(1)
       }
       stringOfDigits :=os.Args[1]
       for row :=range bigDigits[0]{
              line :=""
              for column:=range stringOfDigits{

                     digit:=stringOfDigits[column]-'0'
                     if 0<=digit&&digit<=9{
                            line+=bigDigits[digit][row]+" "
                     }else {
                            log.Fatal("invalid whole number")
                     }
              }
              fmt.Println(line)
       }
}


1.5 栈-自定义类型和其方法

src\stacker\stack\stack.go源码

package stack

import "errors"

type Stack []interface{}

func (stack Stack) Len() int {
       return len(stack)
}

func (stack Stack) Cap() int {
       return cap(stack)
}

func (stack Stack) IsEmpty() bool {
       if len(stack) == 0 {
              return false
       }
       return true
}

func (stack *Stack) Push (x interface{})  {
       *stack = append(*stack,x)
}

func (stack Stack) Top() (interface{},error)  {
       if len(stack) == 0 {
              return nil,errors.New("can't Top en empty stack")
       }
       return stack[len(stack)-1],nil
}

func (stack *Stack) Pop() (interface{},error) {
       theStack := *stack
       if len(theStack) == 0{
              return nil, errors.New("Can't pop an empty stack")
       }
       x := theStack[len(theStack) - 1]
       *stack = theStack[:len(theStack) - 1]
       return x,nil
}

stacker\stacker.go源码

package main

import (
       "fmt"
       "stacker/stack"
)

func main()  {
       var haystack stack.Stack
       haystack.Push("hay")
       haystack.Push(-15)
       haystack.Push([]string{"pin","clip","needle"})
       haystack.Push(81.52)
       for{
              item,err := haystack.Pop()
              if err != nil {
                     break
              }
              fmt.Println(item)
       }
}