An overview of reference types in Go language

Overview of reference types in Go language

Go language is an open source programming language developed by Google. One of its design goals is to be concise, efficient, and easy to use. . In the Go language, reference types are a special data type that store references to data in memory rather than the data itself. This article will introduce reference types in Go language and provide specific code examples.

Reference types include slice, map, channel and function. These types are all reference types in the Go language, so they are passed by reference when passing and assigning, that is, the address of the data in memory is passed, not a copy of the data. This allows you to avoid unnecessary memory overhead when processing large amounts of data.

First, let us look at the use of the reference type slice. A slice is a dynamic array that automatically expands its capacity as needed. Here is a sample code that creates a slice and modifies its elements:

package main

import "fmt"

func main() {
    // 创建一个初始容量为3的切片
    s := make([]int, 0, 3)
    
    // 添加元素到切片中
    s = append(s, 1)
    s = append(s, 2)
    
    // 修改切片中的元素
    s[1] = 3
    
    // 打印切片的内容
    fmt.Println(s)
}

In the above code, we use the make function to create a slice with an initial capacity of 3, and then use ## The #append function adds elements to the slice, modifies the elements in the slice by index, and finally prints out the contents of the slice.

Let’s take a look at the use of mapping (map) types. A map is an unordered collection of key-value pairs that can be used to quickly find and update data. The following is a sample code:

package main

import "fmt"

func main() {
    // 创建一个映射，键为string类型，值为int类型
    m := make(map[string]int)
    
    // 向映射中添加键值对
    m["one"] = 1
    m["two"] = 2
    
    // 修改映射中的值
    m["two"] = 3
    
    // 打印映射的内容
    fmt.Println(m)
}

In the above code, we use the

make function to create a map, then add key-value pairs to the map, and modify the values ​​in the map through the keys , and finally print out the mapped content.

In addition to slicing and mapping, channels and functions are also reference types. Channels are used to transfer data between Go coroutines, and functions are executable blocks of code that can be called. Since channels and functions are also reference types, they are also passed by reference when passed.

In summary, reference types are an important data type in the Go language. They are very useful when processing large amounts of data and complex logic. Through the code examples provided in this article, readers can better understand the concept and usage of reference types, and thus become more proficient in programming in the Go language.

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