Go语言基础(一)

绝地灬酷狼 2022-04-24 09:50 228阅读 0赞

package main
    
    import (
    	"fmt"
    	"math"
    	"reflect"
    	"unsafe"
    )
    type Book struct{
    	ID int
    
    	title string
    	content string
    	author string
    
    }
    var(//因式分解关键字用于声明全局变量,全局变量允许声明但不使用
    
    	r int
    	s int
    	t int
    	e int
    )
    const(
    
    	const1="22aaaa"
    	const2=len(const1)
    	const3=unsafe.Sizeof(const1)
    	const4
    )
    const(
    	//特殊常量
    	iota1=iota
    	iota2
    	iota3
    )
    const(
    
    	iota4 =1<<iota
    	iota5=4<<iota
    	iota6
    	iota7
    	iota8="111"
    	iota9
    	iota10=iota
    	iota11
    	iota12
    	iota13
    	iota14=111
    	iota15
    	iota16
    
    
    )
    const MAX int=3
    var (
    
    	num10 int
    	num11 int
    	num12 *int
    	num13 float32
    )
    func max(num1 int,num2 int) int{
    	if num1<num2{
    		return num2;
    	}
    	return num1;
    }
    
    func main() {
    	//非全局变量不允许声明后不使用
    	fmt.Println("Hello,world!");
    	fmt.Print("Hello,world!\n");
    	var age int;
    	age=1+3;
    	fmt.Println(age);
    	var a bool;
    	fmt.Println(a);
    	fmt.Println("Type:",reflect.TypeOf(a))
    	var b int8;
    	//int8 8位 -128-127
    	//b=127;
    	b=-128
    	fmt.Println(b)
    	fmt.Println("Type:",reflect.TypeOf(b))
    	var c float32;
    	c=1.1111;
    	fmt.Println(c)
    	fmt.Println("Type:",reflect.TypeOf(c))
    	var d complex64;
    	//复数a+bi,一定是i
    	d=1+2i;
    	fmt.Println(d)
    	var e byte;
    	fmt.Println(e)
    
    	var f rune;
    	fmt.Println(f)
    	var g uint;
    	g=1;
    	fmt.Println(g)
    	var h uintptr;
    	h=1;
    	fmt.Println(h)
    	var i string;
    	i="I'm 字符串"
    	fmt.Println(i)
    	var j=10;
    	//判断变量类型
    	fmt.Println("Type:",reflect.TypeOf(j))
    	k:=123.3333
    	fmt.Println("k Type:",reflect.TypeOf(k))
    	l,m,n:=12,"22222",false
    	fmt.Println("l Type:",reflect.TypeOf(l),"m Type:",reflect.TypeOf(m),"n Type:",reflect.TypeOf(n));
    
    	var o,p,q=1,2,3
    	_=o
    	_=p
    	_=q
    
    	fmt.Println(o,p,q)
        r=11
    	fmt.Println(r,s,t)
        fmt.Println("i的地址:",&i)
        var r1,r2=1,1
        r1=r2
    	fmt.Println("&r1:",&r1,r1,"&r2:",&r2,r2)
    
        r2=3
        fmt.Println("r1:",r1,"r2:",r2)
        var str1,str2="111","2222";
        str1=str2
        fmt.Println("&str1:",&str1,str1,"&str2:",&str2,str2)
        const a1,a2,a3=1,2,3
        fmt.Println(a1,a2,a3)
        const a4=0;
        fmt.Println(a4)
        fmt.Println(const1,const2,const3,const4)
        fmt.Println(iota1,iota2,iota3)
    	fmt.Println(iota4,iota5,iota6,iota7,iota8,iota9,iota10,iota11,iota12,iota13,iota14,iota15,iota16)
        fmt.Println("a1:",a1,"a2",a2)
        var c2=a1+a2
    
    
        fmt.Println(c2)
        c2=a1-a2
    
        fmt.Println(c2)
        c2=a1*a2
        fmt.Println(c2)
        c2=a1/a2
        fmt.Println(c2)
        fmt.Println("a1>a2?",a1>a2)
    	fmt.Println("a1>=a2?",a1>=a2)
    	fmt.Println("a1<a2?",a1<a2)
    	fmt.Println("a1<=a2?",a1<=a2)
    	fmt.Println("a1==a2?",a1==a2)
    	fmt.Println("a1!=a2?",a1!=a2)
    	fmt.Println("a1&a2?",a1&a2)
    	fmt.Println("a1|a2?",a1|a2)
    	fmt.Println("!(a1<a2)",!(a1<a2))
        fmt.Println("a^b",a1^a2)
        bool1,bool2:=true,false;
        fmt.Println((bool1&&bool2));
        fmt.Println(bool1||bool2)
        fmt.Println(!bool1&&bool2)
    
        fmt.Println(a1)
        b3,b4:=1,2
        b3=b4
    	fmt.Println("b3:",b3,"b4:",b4)
        b3+=b4
    	fmt.Println("b3:",b3,"b4:",b4)
        b3-=b4
    	fmt.Println("b3:",b3,"b4:",b4)
        b3*=b4
    	fmt.Println("b3:",b3,"b4:",b4)
        b3/=b4
    	fmt.Println("b3:",b3,"b4:",b4)
        var b5 uint;
        var b6 uint;
        b5=10
        b6=11
        b5<<=b6
    	fmt.Println("b5:",b5,"b6:",b6)
        b5>>=b6
    	fmt.Println("b5:",b5,"b6:",b6)
        b5&=b6
    	fmt.Println("b5:",b5,"b6:",b6)
        b5|=b6
    	fmt.Println("b5:",b5,"b6:",b6)
        b5^=b6
    	fmt.Println("b5:",b5,"b6:",b6)
        var c1 int;
        var ptr *int;
        fmt.Println("&c1:",&c1,"ptr:",ptr)
        ptr=&c1;
    	//ptr是c1的地址
        c1=123
    
    
    	fmt.Println("&c1:",&c1,"ptr:",ptr,"*ptr",*ptr)
        a5,a6:=9.4,5.34
        if a5<a6{
    		fmt.Println("a5小于a6")
    	}else if a5==a6{
    		fmt.Println("a5等于a6")
    	}else{
    		fmt.Println("a5大于a6")
    	}
        var a7 int;
        for a7=0;a7<10;a7++{
        	fmt.Println("a7:",a7)
    	}
        var a9=10
        for a7<a9{
    		a7++
        	fmt.Println("a7:",a7)
    
    	}
        nums:=[6]int{1,2,4,5}
        for i1,num:=range nums{
        	fmt.Printf("第%d个值为%d\n",i1,num)
    	}
        fmt.Println("max(4,5)：",max(4,5))
        fmt.Println("min(4,5):",min(4,5))
        var num1 =10
        var num2 =13
    	fmt.Print("交换值前:num1:",num1,"num2:",num2,"\n")
        swap1(num1,num2)
    	fmt.Print("交换值前num1:",num1,"num2:",num2,"\n")
        var num3 *int
    
        var num4 *int
        num3=&num1
        num4=&num2
    	fmt.Print("交换地址后:num3:",*num3,"num4:",*num4,"\n")
        swap2(num3,num4)
    	fmt.Print("交换地址后:num3:",*num3,"num4:",*num4,"\n")
        var num5,num6=130,240
    	fmt.Println("num5:",num5,"num6:", num6);
        num5,num6=swap4(num5,num6)
        fmt.Println("num5:",num5,"num6:", num6);
    
    
        //函数作为值
        getSqrtRoot:=func(x1 float64) float64{
        	return math.Sqrt(x1);
    	}
        fmt.Println(getSqrtRoot(6))
        plusTwoNum:=func(num1 int,num2 int) (int){
        	return num1+ num2;
    	}
        fmt.Println(plusTwoNum(12,3333))
        num11+=1
        num12=&num11
        fmt.Println(num11,*num12,num13)
        var array11 [10]int
        var i2 int
        for  i2=0;i2<10;i2++{
        	array11[i2]=i2
        	fmt.Println(array11[i2])
    	}
        var array12 =[10]int{1,2,3}
        for i2=0;i2<10;i2++{
        	fmt.Println(array12[i2])
        }
        var array13 [10][11]int
        var j2 int
        for i2=0;i2<10;i2++{
        	for j2=0;j2<11;j2++{
        		array13[i2][j2]=i2*j2
        		fmt.Print(array13[i2][j2]," ")
    
    		}
        	fmt.Println()
    	}
        var a14=[3][4]int{
       {1,2,3,4},{0,1,2,4},{-1,-2,-3,-4}}
        for i2=0;i2< len(a14);i2++{
        	for j2=0;j2< len(a14[i2]);j2++{
        		fmt.Print(a14[i2][j2]," ")
    		}
        	fmt.Println()
    	}
        //三维数组
        var a15=[3][4][5]int{
       {
       {1,2,3,4,5},{2,3,4,4,6},{6,7,8,9,0},{11,23,34,5,66}},{
       {1,2,3,4,5},{2,3,4,4,6},{6,7,8,9,0},{11,23,34,5,66}},{
       {1,2,3,4,5},{2,3,4,4,6},{6,7,8,9,0},{11,23,34,5,66}}}
    	var k2 int
        for i2=0;i2< len(a15);i2++{
        	for j2=0;j2< len(a15[i2]);j2++{
        		for k2=0;k2< len(a15[i2][j2]);k2++{
        			fmt.Print(a15[i2][j2][k2]," ")
    			}
    			fmt.Println()
    		}
    		fmt.Println()
    
    	}
        var p1 *int
        var p3 *float32
        if p1!=nil{
        	fmt.Println("p1不为空")
    	}else{
    		fmt.Println("p1为空")
    	}
        if(p3!=nil){
        	fmt.Println("p3不为空")
    	} else{
        	fmt.Println("p3为空")
    	}
        p1=&i2
        var float1 float32=13.4
        p3=&float1
    	if p1!=nil{
    
    		fmt.Println("p1不为空,p1=",p1,"*p1=",*p1)
    	}else{
    		fmt.Println("p1为空")
    	}
    	if p3!=nil{
    
    		fmt.Println("p3不为空,p3=",p3,"*p3=",*p3)
    	}else{
    		fmt.Println("p3为空")
    	}
        a16:=[]int{12,13,14}
        var ptr2 [MAX] *int
        for i2=0;i2<MAX;i2++{
        	ptr2[i2]=&a16[i2]
    	}
        for i2=0;i2< len(ptr2);i2++{
        	//fmt.Println(*ptr2[i2])
        	fmt.Printf("a16[%d]:%d\n",i2,*ptr2[i2])
    	}
        var ptr5 *int
        ptr5=&i2
    
        fmt.Println(*ptr5)
        var ptr55 **int
        ptr55=&ptr5
        fmt.Println(**ptr55)
        var book1 Book
        book1.ID=1
        book1.content="12222"
        book1.title="Python"
        book1.author="aaa"
        fmt.Println("ID:",book1.ID," content:",book1.content," author:",book1.author," title:",book1.title)
        var book [10]Book
        for i2=0;i2<10;i2++{
        	book[i2].ID=i2
        	book[i2].author="author"
        	book[i2].title="title"
        	book[i2].content="content"
    
    
    	}
        fmt.Println(book)
        for i2=0;i2< len(book);i2++{
        	fmt.Println("ID:",book[i2].ID," content:",book[i2].content," author:",book[i2].author," title:",book[i2].title)
    	}
    	printBook(book1)
        printBook2(&book1)
        var slice0 []int
    	if slice0==nil{
    		fmt.Println("切片slice0是空的")
    		fmt.Println("slice0:")
    		printSlice(slice0)
    	}
    
        var  slice1=make([]int,5)
        for i2=0;i2< len(slice1);i2++{
        	slice1[i2]=i2
    	}
       // slice1:=[]int{1,2,3,4,5}
    	fmt.Println("slice1:")
    
        //打印切片
        printSlice(slice1)
        //截取1-4
        fmt.Println("截取1-4，不包括4")
        printSlice(slice1[1:4])
        fmt.Print("截取0-5，不包括5\n")
        printSlice(slice1[0:5])
        /*fmt.Println("截取0-7")
        printSlice(slice1[0:7])*/
        fmt.Println("截取4之前的")
        printSlice(slice1[:4])
        fmt.Println("截取1之后的")
        printSlice(slice1[1:])
        var slice2 []int
        printSlice(slice2)
        //追加空切片
        slice2=append(slice2,0)
    	printSlice(slice2)
        //加一个元素
        slice2=append(slice2,1)
    	printSlice(slice2)
        //加多个元素
        slice2=append(slice2,2,3,4,5,6,7,8)
    	printSlice(slice2)
        //把slice3的容量扩充到slice2的两倍
        slice3:=make([]int,len(slice2),cap(slice2)*2)
        //把slice2的内容拷贝到slice3中
        copy(slice3,slice2)
        printSlice(slice3)
    
        //go语言range
        //求切片的和
        slice4:=[]int{1,2,3,4,5,6,7}
        sum:=0
        for _,s1:=range slice4{
        	sum+=s1
    	}
        fmt.Println("slice4的和为:",sum)
        for i2,s2:=range slice2{
        	fmt.Printf("slice4[%d]=%d\n",i2,s2)
    	}
        //range显示map键值对
        kvs1:=map[string]string{"a":"apple","b":"banana"}
        for k1,v1:=range kvs1{
        	fmt.Println("k1:",k1," v1:",v1)
    	}
        //range枚举unicode字符串
        for i2,c1:=range "Goto学习"{
        	fmt.Println(i2,c1)
    	}
    
    
    
    
    
    
    
    
    
    
    
    
    
    }
    func printSlice(x  []int){
    	fmt.Printf("len=%d,cap=%d,slice=%d\n", len(x), cap(x),x)
    }
    func printBook(book1 Book) {
    	fmt.Println("ID:",book1.ID," content:",book1.content," author:",book1.author," title:",book1.title)
    }
    func printBook2(book1 *Book){
          fmt.Println("ID:",book1.ID," content:",book1.content," author:",book1.author," title:",book1.title)
    }
    func min(num1 int,num2  int) int{
    	if(num1>=num2){
    		return num2
    	}
    	return num1
    }
    func swap1(num1 int,num2 int){
    	t=num1
    	num1=num2
    	num2=t
    	fmt.Print("交换值:num1:",num1,"num2:",num2,"\n")
    }
    func swap2(num3 *int,num4 *int){
    	t=*num3
    	*num3=*num4
    	*num4=t
    	//fmt.Print("&num3:",num3,"&num4:",num4)
    	fmt.Print("交换地址:num3:",*num3,"num4:",*num4,"\n")
    }
    //函数返回多个值
    func swap4(num5 int,num6 int) (int,int){
    	t=num5
    	num5=num6
    	num6=t
    	return num5,num6
    }