How to delete map key in Go language

Golang is a modern programming language that has received more and more attention in recent years. As a language designed for high concurrency and large-scale project development, many features of Golang are designed to support fast and efficient development and operation.

One of the very important features is its built-in data types and data structures, among which map is widely used. For unfamiliar developers, they may not know how to delete the key in the map. In this article, we will discuss how to delete map key in Golang.

Introduction

First of all, what we need to know is that map is an unordered data structure built into Golang, which stores data in a key-value manner. In Golang, we can easily create and use maps through the following simple example:

m := make(map[string]int)
m["apple"] = 1
m["banana"] = 2
fmt.Println(m)

Output:

map[apple:1 banana:2]

When the map is no longer needed, we need to release the memory it occupies. Memory. Before we delete the map key, let us first take a look at some basic knowledge of map in Golang.

How to access map elements

In Golang, we can access map elements through keys. For example, we can get the value from the map created above by:

fmt.Println(m["apple"])

Output:

1

Please note that if we try to access a key that does not exist in the map, then we will will get a default value.

fmt.Println(m["coconut"])

Output:

0

The elements in map are unordered:

Map is an unordered data structure, which means we cannot guarantee the order of reading. are consistent. Therefore, we should follow this principle when using map.

Delete the key in the map

Now that we have understood some basic knowledge, let us take a look at how to delete the key of the map in Golang. There are two methods in Golang to delete the key in the map:

1. Use the delete function

Using Golang's built-in function delete(), we can delete the specified key in the map. For example, we can delete "banana" from the map created above by:

delete(m, "banana")
fmt.Println(m)

Output:

map[apple:1]

Please note that if the deleted key does not exist in the map, the program will not Throws an exception and only leaves the map unchanged. However, if you try to delete a key from an empty map, an error will be thrown.

2. Use for...range loop

Another way to delete keys in the map is to use a for...range loop to traverse the map and delete the key we need to delete through conditional statements. For example:

for k := range m {
    if k == "apple" {
        delete(m, k)
    }
}
fmt.Println(m)

Output:

map[]

Please note that if we want to delete all keys in the map, we can use a for loop combined with the delete() function to achieve this.

Summary

In this article, we learned how to delete the map key in Golang. We can easily delete keys in the map through the built-in delete function and for...range loop method.

Since Golang’s map is a very important and widely used data structure, it is very important to learn how to delete keys in the map. This can help developers better manage memory and improve application efficiency and performance. .

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