慕课网Go-2.数组、slice、map、list

数组

package mainimport "fmt"func main() {var course1 [3]stringcourse1[0] = "go"course1[1] = "grpc"course1[2] = "gin"for _, value := range course1 {fmt.Println(value)}course2 := [3]string{2: "grpc"}fmt.Println(course2)course3 := [...]string{"go", "grpc"}fmt.Println(course3)//多维数组var courseinfo [3][4]stringcourseinfo[0] = [4]string{"go1", "1h", "neo1", "基础1"}courseinfo[1] = [4]string{"go2", "2h", "neo2", "基础2"}courseinfo[2] = [4]string{"go3", "3h", "neo3", "基础3"}for i := 0; i < len(courseinfo); i++ {for j := 0; j < len(courseinfo[0]); j++ {fmt.Print(courseinfo[i][j] + " ")}fmt.Println()}
}

slice

package mainimport ("fmt""strconv"
)func changeSlice(data []string) {data[0] = "change!" //生效for i := 0; i < 5; i++ {data = append(data, strconv.Itoa(i)) //不生效，扩容导致地址改变}
}func main() {//初始化allCourse1 := [5]string{"go", "grpc", "gin", "mysql", "search"}fmt.Println(allCourse1)allCourse2 := [5]string{"go", "grpc", "gin", "mysql", "search"}courseLine := allCourse2[0:4] //左闭右开fmt.Println(courseLine)allCourse3 := make([]string, 3, 5) //len、capallCourse3[0] = "c"fmt.Println(allCourse3)var allCourse4 []stringallCourse4 = append(allCourse4, "go")allCourse4 = append(allCourse4, "grpc", "gin")fmt.Println(allCourse4)//访问，同pythonfmt.Println(allCourse1[:])fmt.Println(allCourse1[0:4])//拼接courseSlice1 := []string{"go", "grpc"}courseSlice2 := []string{"gin", "mysql"}courseSlice1 = append(courseSlice1, courseSlice2[:]...)fmt.Println(courseSlice1)//删除courseSlice3 := []string{"go", "grpc", "gin", "sql"}mySlice := append(courseSlice3[:2], courseSlice3[3:]...)fmt.Println(mySlice)//复制fmt.Println("复制")courseCopy := courseSlice1 //不独立courseSlice1[0] = "java1"fmt.Println(courseSlice1)fmt.Println(courseCopy)courseCopy2 := courseSlice1[:] //不独立courseSlice1[0] = "java2"fmt.Println(courseSlice1)fmt.Println(courseCopy2)courseCopy3 := make([]string, len(courseSlice1))copy(courseCopy3, courseSlice1) //独立courseSlice1[0] = "java3"fmt.Println(courseSlice1)fmt.Println(courseCopy3)//值传递原理data := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}s1 := data[1:6]s2 := data[2:7]//cap在512以内为2的幂，略大于等于len//扩容导致指向data副本,s1和s2不再指向同一个slices2 = append(s2, 11, 12, 13, 14, 15, 16, 17, 18, 19, 1, 1, 1, 1, 1, 1, 1, 1, 1)fmt.Println(s1)fmt.Println(s2)s2[2] = 22fmt.Println(s1) //不再改变fmt.Println(s2)courseChange := []string{"go", "grpc", "gin", "sql"}changeSlice(courseChange)fmt.Println(courseChange)
}

map

package mainimport "fmt"func main() {var courseMap = map[string]string{"go":   "go1","grpc": "grpc1","gin":  "gin1",}//var courseMap1=make(map[string]string,3)courseMap["sql"] = "mysql"fmt.Println(courseMap["sql"])for key, value := range courseMap {fmt.Println(key, value)}d, ok := courseMap["java"]//若不存在，则值为""fmt.Println(d, ok) //"",falsedelete(courseMap, "gin")delete(courseMap, "cpp")//不存在也不会报错
}

list

package mainimport ("container/list""fmt"
)func main() {var myList list.ListmyList.PushBack("go")myList.PushBack("grpc")myList.PushBack("gin")fmt.Println(myList) //指针myList.PushFront("sql")myList.InsertBefore("last", myList.Back())for it := myList.Front(); it != nil; it = it.Next() {fmt.Println(it.Value)}for it := myList.Back(); it != nil; it = it.Prev() {fmt.Println(it.Value)}
}