/*** @Author: FB* @Description: * @File:  SliceMapInit.go* @Version: 1.0.0* @Date: 2019/7/5 14:39*/package mainimport "fmt"func main(){InitSlice()InitMap()
}func InitSlice(){//三个等价var a []intvar a1 = []int{}var b = make([]int,0)var b2 = make([]int,0,0)//报错//a[0] = 1//b[0] = 2showVals(a,a1,b,b2)showVals("---------end 1---------")//三个等价var c = []int{0,0,0}var d = make([]int,3)var d2 = make([]int,3,3)var d3 = make([]int,3,5)c[0] = 1d[0] = 2showVals(c,d,d2)showVals("---------end 2---------")//报错，因为长度只有3//d[3] = 3showVals(d,len(d),cap(d))//报错，因为长度只有3//d3[3] = 3showVals(d3,len(d3),cap(d3))showVals("---------end 3---------")//append 以上两种情况都可以a = append(a,1,2,3)b = append(b,1,2,3)d = append(d,1,2,3)d3 = append(d3,1,2,3)showVals("a",a,len(a),cap(a))showVals("b",b,len(b),cap(b))showVals("d",d,len(d),cap(d))showVals("d3",d3,len(d3),cap(d3))}func InitMap(){var a map[string]stringshowVals(a)// add these lines:/*myGreeting["Tim"] = "Good morning."myGreeting["Jenny"] = "Bonjour."*/// and you will get this:// panic: assignment to entry in nil map//OKvar b = make(map[string]string)//等价写法shorthand_make//b := make(map[string]string)//initb["Tim"] = "Good morning."b["Jenny"] = "Bonjour."showVals(b)//OKc := map[string]string{}//initc["Tim"] = "Good morning."c["Jenny"] = "Bonjour."showVals(c)//initc1 := map[string]string{"Tim":   "Good morning!","Jenny": "Bonjour!",}c1["FB"] = "Hi"c1["Jenny"] = "Hello"c1["Jenny2"] = "Hello2"showVals(c1,len(c1))delete(c1,"Jenny2")showVals(c1)//key := "FB2"key := "FB"if val, exists :=  c1[key];exists{showVals(val)delete(c1,key)showVals(c1)}else{showVals("no found",key)}//遍历for key, val := range c1 {fmt.Println(key, " - ", val)}}func showVals(vals ...interface{}){for _,v :=range vals{fmt.Print(v,"\t")}fmt.Println()
}