Learn the principles and applications of Go language slicing from scratch

Learn the principles and applications of Go language slicing from scratch

The slice in Go language is a dynamic array and an encapsulation of the array. Has its own length and capacity and can grow dynamically as needed. Slicing is very commonly used in the Go language. Mastering the principles and applications of slicing is very important to improve programming efficiency. This article will introduce the principles and applications of Go language slicing from scratch, and provide specific code examples to help readers better understand.

Basic concept of slicing

In Go language, slice is a reference data type, which is a structure that points to the pointer, length and capacity of the underlying array. The declaration of a slice is as follows:

var slice []int // 声明一个int类型的切片

A slice can be created through the make function, or a part of an existing array can be intercepted through a slice expression. The basic operations of slicing include obtaining the length and capacity of the slice, adding elements to the slice, intercepting the slice, etc.

Application of slices

1. Create slices

// 创建一个长度为5，容量为10的切片
slice := make([]int, 5, 10)

2. Add elements

// 向切片末尾添加元素
slice = append(slice, 6, 7, 8)

3. Intercept slices

// 截取切片中的一部分
newSlice := slice[1:3] // 从索引1到索引2（不包括3）的元素

4. Traversing slices

for index, value := range slice {
    fmt.Printf("索引：%d, 值：%d
", index, value)
}

The principle of slices

The underlying data structure of a slice contains a pointer to the arrayptr, the length of the slicelen and the length of the slice Capacitycap. When we assign one slice to another, they actually point to the same underlying array. If one of the slices modifies elements of the underlying array, the other slice will also be affected.

When we add elements to the slice, if the capacity of the slice is insufficient, the Go language will reallocate a larger underlying array and copy the original elements to the new array. This is why when using the append function, the return value needs to be reassigned to the original slice.

Sample code

Let’s take a look at a complete sample code to demonstrate how to use slices to operate:

package main

import "fmt"

func main() {
    // 创建一个长度为3，容量为5的切片
    slice := make([]int, 3, 5)

    // 添加元素
    slice = append(slice, 4, 5, 6)

    // 遍历切片
    for index, value := range slice {
        fmt.Printf("索引：%d, 值：%d
", index, value)
    }

    // 截取切片
    newSlice := slice[1:3]

    // 修改切片元素
    newSlice[0] = 100

    // 原切片也受到影响
    fmt.Println(slice) // [0 100 0 0 0 4 5 6]
}

Through the above sample code, we can see how to create, Manipulate and modify slices. Mastering the principles and applications of slicing is crucial to writing efficient and concise Go language code. Through the introduction of this article, readers can have a deeper understanding of Go language slicing, and can flexibly use slicing to optimize their program design.

The above is the detailed content of Learn the principles and applications of Go language slicing from scratch. For more information, please follow other related articles on the PHP Chinese website!