golang modification tutorial

Go language is an open source programming language launched by Google in 2009. It has simple syntax, easy to use, high efficiency, concurrency and other features. It has become one of the mainstream languages ​​used by developers. With the continuous development of software development, modifying code has become one of the common operations. This article will introduce how to use Golang to modify code, so that you can develop code more conveniently.

1. Modify variable values

Modifying variables in Go language is very simple, you just need to reassign the variable value. For example, the following example:

package main

import "fmt"

func main() {
    var num1 int = 10
    var num2 int = 20
    fmt.Println("num1=", num1, "num2=", num2)

    // 修改num1的值为30
    num1 = 30
    fmt.Println("num1=", num1, "num2=", num2)
}

Running results:

num1= 10 num2= 20
num1= 30 num2= 20

In this example, we first define two integer variables num1 and num2, and use the Println function of the fmt package to output their value. Then we modify the value of num1 to 30 and output the values ​​of the two variables again. You can see that the value of num1 has been modified to 30 at this time, while the value of num2 is still 20.

2. Modify the string

Modifying the string in the Go language is similar to modifying the variable. You only need to reassign the string variable. For example, the following example:

package main

import "fmt"

func main() {
    var str1 string = "Hello"
    var str2 string = "World"
    fmt.Println("str1=", str1, "str2=", str2)

    // 修改str1的值为"Hi"
    str1 = "Hi"
    fmt.Println("str1=", str1, "str2=", str2)
}

Running results:

str1= Hello str2= World
str1= Hi str2= World

In this example, we first define two string variables str1 and str2, and use the Println function of the fmt package to output their value. Then we modify the value of str1 to "Hi" and output the values ​​of the two variables again. At this time, you can see that the value of str1 has been modified to "Hi", while the value of str2 is still "World".

3. Modify array elements

Modifying array elements in Go language requires access using array subscripts. For example, the following example:

package main

import "fmt"

func main() {
    var arr [5]int = [5]int{1, 2, 3, 4, 5}
    fmt.Println("arr=", arr)

    // 修改arr[2]的值为8
    arr[2] = 8
    fmt.Println("arr=", arr)
}

Running result:

arr= [1 2 3 4 5]
arr= [1 2 8 4 5]

In this example, we first define an integer array arr with a length of 5, and use the Println function of the fmt package to output it value. Then we modify the value of arr[2] to 8 and output the value of the entire array again. At this time, you can see that the value of arr[2] in the array has been modified to 8.

4. Modify slice elements

Slices are a very powerful data structure in the Go language. We use it to describe variable-length sequences composed of elements of the same type. . Modifying slice elements also requires subscript access. For example, the following example:

package main

import "fmt"

func main() {
    var slice []int = []int{1, 2, 3, 4, 5}
    fmt.Println("slice=", slice)

    // 修改slice[2]的值为8
    slice[2] = 8
    fmt.Println("slice=", slice)
}

Running result:

slice= [1 2 3 4 5]
slice= [1 2 8 4 5]

In this example, we first define an integer slice slice and use the Println function of the fmt package to output its value. Then we modify the value of slice[2] to 8 and output the value of the entire slice again. At this time, you can see that the value of slice[2] in the slice has been modified to 8.

5. Modify structure member variables

In Go language, structure is a custom user-defined type, usually used to represent complex data structures. Modifying structure member variables also requires the member access operator ".". For example, the following example:

package main

import "fmt"

type Person struct {
    Name string
    Age  int
}

func main() {
    var p1 Person = Person{"Tom", 20}
    fmt.Println("p1=", p1)

    // 修改p1的Age值为25
    p1.Age = 25
    fmt.Println("p1=", p1)
}

Running result:

p1= {Tom 20}
p1= {Tom 25}

In this example, we first define a structure named Person and use the structure literal to create a structure named The structure variable of p1, and use the Println function of the fmt package to output its value. Then we modify the value of the Age member variable of p1 to 25, and output the value of the entire structure again. At this time, you can see that the value of the Age member variable of p1 has been modified to 25.

Summary

As can be seen from the above introduction, the Go language is very convenient and easy to use for code modification, and can quickly perform various modification operations. In actual project development, code modification is one of the most common operations. Therefore, mastering the relevant skills of Golang modification will be of great help to improve the daily work efficiency of developers.

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