map操作

main.go

@@ -1,28 +1,62 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+)
 
 func main() {
-	//创建方式1
-	//定义map变量
-	var a map[int]string
-	//必须通过make初始化才会分配空间
-	a = make(map[int]string)
-
-	a[100] = "Hello"
-	a[200] = "World"
-	fmt.Println(a)
 
 	//创建方式2
 	b := make(map[int]string)
+	//增加
 	b[100] = "Hello"
 	b[200] = "World"
+
+	//修改
+	b[200] = "wd"
 	fmt.Println(b)
 
-	//方式3
-	c := map[int]string{
-		100: "Hello",
-		200: "World",
+	//删除
+	delete(b, 200)
+	fmt.Println(b)
+
+	//查找
+	value, flag := b[100]
+	fmt.Println("查找的内容", value)
+	fmt.Println("查找是否成功", flag)
+
+	//获取长度
+	fmt.Println("长度", len(b))
+
+	//遍历
+	for i, s := range b {
+		fmt.Printf("第%d个是:%s\n", i, s)
 	}
+
+	//双重map
+	c := make(map[string]map[int]string)
+	c["a"] = make(map[int]string)
+	c["a"][1555] = "A"
+	c["a"][2666] = "B"
+	c["a"][3777] = "C"
+	c["a"][4888] = "D"
 	fmt.Println(c)
+
+	d := map[string]map[int]string{
+		"a": {
+			1555: "A",
+			2666: "B",
+		},
+		"b": {
+			1555: "A",
+			2666: "B",
+		},
+	}
+	for s, m := range d {
+		fmt.Printf("学生班级为%v\n", s)
+		for i, i2 := range m {
+			fmt.Printf("学生学号为%v 姓名为%v\n", i, i2)
+		}
+
+	}
 }