Golang map进行操作，遍历

一时失言乱红尘 2023-02-19 08:29 10阅读 0赞

package main
    
    import "fmt"
    
    func main() {
    	//map 操作
    	city := make(map[string]string)
    	//赋值 --增加-更新
    	city["beijing"] = "北京"
    	city["shanghai"] = "上海"
    	city["shenzhen"] = "深圳"
    	fmt.Println(city)			//map[beijing:北京 shanghai:上海 shenzhen:深圳]
    	//更新
    	city["beijing"] = "北京京"
    	//查找
    	k,ok := city["beijing"]
    	if ok {
    		fmt.Printf("有值--%s\n",k)		//有值--北京京
    	} else {
    		fmt.Println("没有值")
    	}
    	fmt.Println(city["beijing"])	//北京京
    	//map的遍历
    	for k,v := range city {
    		fmt.Printf("key: %s value: %s\n",k,v)
    	}
    	//key: beijing value: 北京京
    	//key: shanghai value: 上海
    	//key: shenzhen value: 深圳
    	fmt.Println(city)				//map[beijing:北京京 shanghai:上海 shenzhen:深圳]
    
    	//删除
    	delete(city,"beijing")		//map[shanghai:上海 shenzhen:深圳]
    	fmt.Println(city)
    	//直接重新分配空间==删除
    	city = make(map[string]string)
    	fmt.Println(city)				//map[]
    
    	//双重map的遍历
    	people := make(map[string]map[string]string)
    	people["son"] = make(map[string]string)
    	people["son"]["age"] = "12"
    	people["son"]["name"] = "tt"
    	people["son"]["addr"] = "beijing"
    
    	people["guys"] = make(map[string]string)
    	people["guys"]["age"] = "20"
    	people["guys"]["name"] = "pp"
    	people["guys"]["addr"] = "上海"
    
    	//k1:  son
    	//key2: age value2: 12
    	//key2: name value2: tt
    	//key2: addr value2: beijing
    	//k1:  guys
    	//key2: name value2: pp
    	//key2: addr value2: 上海
    	//key2: age value2: 20
    	for k1,v1 := range people {
    		fmt.Println("k1: ",k1)
    		for k2,v2 :=range v1 {
    			fmt.Printf("key2: %s value2: %s\n",k2,v2)
    		}
    	}
    
    	fmt.Println("len(people): ",len(people))				//2
    	fmt.Println("len(people-son): ",len(people["son"]))		//3
    	fmt.Println("len(people-guys): ",len(people["guys"]))	//3
    }