How to implement golang map deletion

Golang is a fast, efficient, cross-platform programming language. As one of the more popular programming languages, it has rich features and various advanced data structures, such as map. Map is a very commonly used built-in data structure in Golang. It can easily store key-value pair data in the program. Map provides convenient operations, such as adding, deleting, modifying, etc. However, it is often the case that you forget to delete some data in the map. This will cause the program to occupy too much memory. Therefore, when using Map, the deletion operation is very difficult. important. This article will introduce the deletion operation of Golang Map.

First of all, map in Golang is an unordered collection of key-value pairs, used to store unordered data of any type, and can be regarded as a hash table or dictionary in other languages. Usually, the basic format of map is as follows:

var mapName map[keyType]valueType

Among them, mapName is the defined mapping name, keyType and valueType are the key and The type of value. When defining and initializing a map, you usually need to use the make() function for initialization.

The deletion operation of map in Golang can use the built-in function delete(), its format is as follows:

delete(mapName, key)

Among them, mapName is the one that needs to be operated The name of the map, key is the key name in the key-value pair that needs to be deleted. The following is a sample code for a map deletion operation:

//定义map
mapName := make(map[string]string)

//添加数据
mapName["A"] = "Value A"
mapName["B"] = "Value B"
mapName["C"] = "Value C"
mapName["D"] = "Value D"
mapName["E"] = "Value E"

//删除数据
delete(mapName, "C")

//打印map
fmt.Println(mapName)

In the above code, we first define a string type mapName and add five sets of key-value pair data to it. Next, we use the delete() function to delete the data with key C in the map, and finally output the map. You can see that data C has been successfully deleted.

It should be noted that if we use the delete() function to delete a key-value pair that does not exist, no error will be reported and no operation will be performed, so there is no need to worry about the deletion not existing Key-value pairs can cause problems.

In addition, it should be noted that deleting the data in the map will not release the memory space occupied by the map. If you need to release the memory space, you need to use other algorithms or re-create a map instance.

In short, in Golang, map is an efficient and convenient data structure, and the deletion operation is also very simple. When using map in the program, we should pay attention to deleting useless data in time to avoid excessive memory usage and Cause the program to crash.

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