How to use struct method in go language

Usage of struct method in go language: 1. Define the struct type. Inside the function, we can create a variable of struct type and assign values ​​to its fields; 2. Define a method for the struct type. The method is A special type of function, associated with a certain type. To define a method, you need to add a receiver before the function name; 3. Define the method of the pointer receiver. The pointer receiver allows us to modify the structure pointed to by the method receiver. Example.

#The operating environment of this article: Windows 10 system, go1.20 version, dell g3 computer.

Go language is a statically typed programming language that provides rich data structures and methods to process data. One of the commonly used data structures is struct, which allows us to define a custom type that contains fields of different types. In this article, I will introduce you how to use struct and its methods in Go language.

1. Define the struct type. A struct type can contain multiple fields, each with its own type and name. Inside the function we can create a variable of type struct and assign values ​​to its fields. Here is an example:

package main
import "fmt"
type Person struct {
name string
age int
}
func main() {
person := Person{name: "Alice", age: 25}
fmt.Println(person)
}

In the above example, we defined a struct type named Person, which has two fields: name and age. In the main function, we create a variable person of type Person and assign values ​​to its name and age fields. Finally, we use the fmt package to print out the value of person.

2. Define methods for the struct type. A method is a special type of function that is associated with a type. Within methods we can use fields and other methods of types. To define a method, we need to precede the function name with a receiver. The receiver is a parameter that represents the type of the calling method. The following is an example of using the struct method:

package main
import "fmt"
type Person struct {
name string
age int
}
func (p Person) introduce() {
fmt.Println("My name is", p.name, "and I am", p.age, "years old.")
}
func main() {
person := Person{name: "Alice", age: 25}
person.introduce()
}

In the above example, we defined an introduce method for the Person type. The receiver of this method is a parameter p of type Person. Inside the method, we use p's name and age fields to print out a self-introduction sentence. In the main function, we create a variable person of type Person and call the introduce method of person.

3. Define the method of pointer receiver. Pointer receivers allow us to modify the structure instance pointed to by the method receiver. This is useful when the receiver needs to be modified. The following is an example of a method using a pointer receiver:

package main
import "fmt"
type Person struct {
name string
age int
}
func (p *Person) incrementAge() {
p.age++
}
func main() {
person := Person{name: "Alice", age: 25}
fmt.Println("Before increment:", person.age)
person.incrementAge()
fmt.Println("After increment:", person.age)
}

In the above example, we define an incrementAge method for the Person type, and the receiver of this method is a pointer to the Person type. Inside the method, we increment the receiver's age field. In the main function, we create a variable person of type Person and call the incrementAge method of person. When printing out the age value before and after the auto-increment, we can see that the age field has indeed been modified.

Through the introduction of this article, you should understand how to use struct and its methods in Go language. Struct allows us to define and organize data, and methods allow us to perform specific operations on data. This makes the Go language very powerful and flexible when dealing with complex data structures and objects. I hope this article will help you learn and use the Go language!

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