字典的创建

make(map[KeyType]ValueType, initialCapacity)

make(map[KeyType]ValueType…

字典的创建

1. make(map[KeyType]ValueType, initialCapacity)

2. make(map[KeyType]ValueType)

3. map[KeyType]ValueType{}

4. map[KeyType]ValueType{key1 : value1, key2 : value2, … , keyN : valueN}

   func test1() {
   map1 := make(map[string]string, 5)
   map2 := make(map[string]string)
   map3 := map[string]string{}
   map4 := map[string]string{“a”: “1”, “b”: “2”, “c”: “3”}
   fmt.Println(map1, map2, map3, map4)
   }

字典的填充和遍历

func test2() {
    map1 := make(map[string]string)
    map1["a"] = "1"
    map1["b"] = "2"
    map1["c"] = "3"
    for key, value := range map1 {
        fmt.Printf("%s->%-10s", key, value)
    }
}

字典的查找、修改和删除

func test3() {
    map4 := map[string]string{"a": "1", "b": "2", "c": "3"}
    val, exist := map4["a"]
    val2, exist2 := map4["d"]
    fmt.Printf("%v,%v\n", exist, val)
    fmt.Printf("%v,%v\n", exist2, val2)
    map4["a"] = "8" // 修改字典和添加字典没什么区别
    fmt.Printf("%v\n", map4)
    fmt.Println("删除b：")
    delete(map4, "b")
    fmt.Printf("%v", map4)
}

访问字典，安全的放法

map4 := map[string]string{"a": "1", "b": "2", "c": "3"}
val, exist := map4["d"]
if exist {
    fmt.Println(val)
} else {
    fmt.Println("not exists")
}