add map slice

Map/main.go

@@ -0,0 +1,153 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"sort"
+)
+
+func main() {
+	myMap := make(map[string]int)
+	myMap["song"] = 1
+	myMap["zong"] = 2
+	fmt.Println(myMap)
+
+	myMap2 := map[string]string{
+		"123": "123",
+		"456": "456",
+	}
+	fmt.Println(myMap2)
+
+	key, value := IsExist()
+	if value {
+		fmt.Printf("%v\n", key)
+	} else {
+		fmt.Printf("查无此人: %v\n", key)
+	}
+	RangeMap()
+
+	DeleteKey("003")
+
+	RangeMap2()
+
+	MapSlice()
+
+	SliceMap()
+}
+
+// IsExist 键是否存在
+func IsExist() (int, bool) {
+	fmt.Println("===IsExist===")
+	mMap := make(map[string]int)
+	mMap["张三"] = 333
+	mMap["李四"] = 444
+	v, ok := mMap["张三"]
+	return v, ok
+}
+
+// RangeMap 遍历
+func RangeMap() {
+	fmt.Println("===RangeMap===")
+	rMap := map[string]string{
+		"001": "张三",
+		"002": "李四",
+		"003": "王五",
+		"004": "周六",
+	}
+	for k, v := range rMap {
+		fmt.Println(k, v)
+	}
+	fmt.Println("range key")
+
+	for rk := range rMap {
+		fmt.Println(rk)
+	}
+}
+
+// DeleteKey 删除键
+func DeleteKey(key string) {
+	fmt.Println("===DeleteMap===")
+	dMap := map[string]string{
+		"001": "张三",
+		"002": "李四",
+		"003": "王五",
+		"004": "周六",
+	}
+	delete(dMap, key)
+	for k, v := range dMap {
+		fmt.Println(k, v)
+	}
+}
+
+// RangeMap2 指定顺序遍历
+func RangeMap2() {
+	fmt.Println("===RangeMap2===")
+	scoreMap := make(map[string]int, 200)
+
+	for i := 0; i < 20; i++ {
+		key := fmt.Sprintf("stu%02d", i)
+		value := rand.Intn(100)
+		scoreMap[key] = value
+	}
+	//fmt.Println(scoreMap)
+	//将key存入切片
+	keys := make([]string, 0, 200)
+	fmt.Println("排序前")
+	for key := range scoreMap {
+		keys = append(keys, key)
+		fmt.Printf("%v: %v ", key, scoreMap[key])
+	}
+
+	sort.Strings(keys)
+
+	fmt.Println("\n排序后")
+	//for i := 0; i < len(keys); i++ {
+	//	fmt.Printf("%v ", scoreMap[keys[i]])
+	//}
+
+	for _, key := range keys {
+		fmt.Printf("%v: %v ", key, scoreMap[key])
+	}
+	fmt.Println()
+}
+
+func test() {
+	SliceMap()
+}
+
+// MapSlice 元素为map类型的切片
+func MapSlice() {
+	fmt.Println("===元素为map类型的切片===")
+	//先申明并初始化一个map“切片”
+	mapSlice := make([]map[string]string, 3)
+	for index, value := range mapSlice {
+		fmt.Printf("index: %v, value: %v\n", index, value)
+	}
+	//在对切片中的map进行初始化
+	mapSlice[0] = make(map[string]string, 10)
+	mapSlice[0]["name"] = "swansong"
+	mapSlice[0]["age"] = "22"
+	mapSlice[0]["sex"] = "man"
+
+	for index, value := range mapSlice {
+		fmt.Printf("index: %v, value:%v\n", index, value)
+	}
+}
+
+// SliceMap 值为切片类型的map
+func SliceMap() {
+	fmt.Println("===值为切片的map===")
+	sliceMap := make(map[string][]string, 3)
+	//for index, value := range sliceMap {
+	//	fmt.Printf("index: %v, value: %v", index, value)
+	//}
+	fmt.Println(sliceMap)
+	key := "中国"
+	value, ok := sliceMap[key]
+	if !ok {
+		value = make([]string, 0, 2)
+	}
+	value = append(value, "北京", "上海")
+	sliceMap[key] = value
+	fmt.Println(sliceMap)
+}

Practices/mapslice/main.go

@@ -0,0 +1,35 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+)
+
+/**
+ *写一个程序，统计一个字符串中每个单词出现的次数。比如：”how do you do”中how=1 do=2 you=1。
+ */
+
+func main() {
+	str := "how do you do"
+	strMap := make(map[string]int, 10)
+	strSlice := strings.Split(str, " ")
+	for _, value := range strSlice {
+		_, ok := strMap[value]
+		if ok {
+			strMap[value]++
+		} else {
+			strMap[value] = 1
+		}
+	}
+	keys := []string{}
+	for key := range strMap {
+		keys = append(keys, key)
+	}
+
+	sort.Strings(keys)
+
+	for _, key := range keys {
+		fmt.Printf("%v: %v ", key, strMap[key])
+	}
+}