golang map delete all

In Golang, map is a very commonly used data structure that can easily store and access key-value pair data. When using map, sometimes you need to delete all key-value pair data. This article will introduce how to delete all data in golang map.

Introduction to Golang Map

Map is a collection type in Golang, used to store key-value pair data. Each element in the Map is a key-value pair, where the key is a unique identifier and the value is any type of data. The elements in the Map are unordered, so the elements in the Map cannot be accessed through subscripts.

Declaration of Golang Map

In Golang, you can declare a map in the following way:

// 声明一个键为string类型，值为任意类型的map
var myMap map[string]interface{}

// 声明一个键为int类型，值为string类型的map
var myMap map[int]string

As you can see, you need to specify the key and value types when declaring a map. . Of course, you can also use the make() function to initialize a map:

// 声明一个键为string类型，值为任意类型的map
myMap := make(map[string]interface{})

// 声明一个键为int类型，值为string类型的map
myMap := make(map[int]string)

Add/modify elements in the map

The way to add/modify elements in the map is also very simple, you can directly Map performs assignment operations:

// 声明并初始化一个map
myMap := make(map[string]string)

// 添加元素
myMap["key1"] = "value1"

// 修改元素
myMap["key1"] = "newValue"

Delete elements in map

In Golang, you can use the delete() function to delete key-value pairs specified in the map

// 声明并初始化一个map
myMap := make(map[string]string)

// 添加元素
myMap["key1"] = "value1"

// 删除元素
delete(myMap, "key1")

Delete all the elements of the map

If you need to delete all the elements of the map, we can use the following two methods:

Method 1: Loop deletion

This method is more straightforward, You can use a for loop to iterate through all elements in the map, and then use the delete() function to delete the elements.

// 声明并初始化一个map
myMap := make(map[string]string)

// 添加元素
myMap["key1"] = "value1"
myMap["key2"] = "value2"

// 使用for循环删除
for key := range myMap {
    delete(myMap, key)
}

It should be noted that when using a for loop to traverse a map, you cannot use subscripts and can only use the range keyword to traverse. Otherwise, panic will occur.

Method 2: Use the make() function to re-create a map

This method is relatively simple, just use the make() function to re-create an empty map.

// 声明并初始化一个map
myMap := make(map[string]string)

// 添加元素
myMap["key1"] = "value1"
myMap["key2"] = "value2"

// 使用make()函数新建一个map
myMap = make(map[string]string)

This method is relatively simple, but it is not suitable for large maps because memory space needs to be reallocated when creating a new map, which may affect the performance of the program.

Summary

Golang map is a very commonly used data structure that can easily store and access key-value pair data. When using map, we need to frequently clear its elements. This article introduces two methods of clearing map elements: loop deletion and re-creating an empty map. Different methods need to be selected according to the actual situation.

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