golang method call

Go language is an efficient, concise and reliable programming language, which has been favored by developers in recent years. In Go language, method calling is a common operation and plays an important role in many applications. This article will deeply explore the basic principles, grammatical rules and practical skills of method calling in Go language.

1. Basic principles

In the Go language, method calls follow the following basic principles:

1. A method is a set of related functions that work together to perform a certain function. function.

2. In the Go language, method calls are similar to ordinary function calls. They require a pair of parentheses after the method name, and parameters can be passed within the parentheses.

3. Methods in the Go language can be defined as value types and reference types. Value type methods can only operate on copies of the receiver, while reference type methods can directly operate on the receiver itself.

4. Methods can be defined in any data structure, including struct, interface, array, etc.

2. Grammar rules

In the Go language, the grammar rules of methods are as follows:

1. The format of defining a method is:

func (receive receiver type) method name (parameter list) (return value list) {}

where the receiver type can be a value type or a reference type, the method name is usually a descriptive word or phrase, the parameter list and The return value list is optional.

2. The format of calling a method is:

Receiver.Method name (parameter list)

Among them, the receiver can be a variable of value type or reference type, method The name and parameter list must be exactly the same as the method name and parameter list defined by the receiver type, and the method must be implemented by the type.

3. Practical skills

In practical applications, we often need to use method calls to implement complex logical functions. Below, we'll cover some practical tips for making better use of method calls in Go.

1. Use pointer receiver types whenever possible

Methods of value types can only operate on copies of the receiver, while methods of reference types can directly operate on the receiver itself. Therefore, when designing data structures, we should usually give priority to using pointer types as the receivers of methods in order to achieve more flexible and efficient data operations.

For example, the following is a simple struct type, we can operate it by defining the pointer type method:

type User struct {

name   string
gender string
age    int

}

func (u *User) SetName(name string) {

u.name = name

}

func (u *User) SetGender(gender string) {

u.gender = gender

}

func (u *User) SetAge(age int) {

u.age = age

}

2. Make full use of interface type method calls

In Go language, Method calling of interface types is a powerful feature that can help us achieve flexible and extensible programming.

For example, the following is a simple interface type definition. We can implement different operations through the methods of the interface type:

type Shape interface {

Area() float64
Perimeter() float64

}

func main() {

rect := &Rectangle{20, 30}
fmt.Println("Rectangle area:", rect.Area())
fmt.Println("Rectangle perimeter:", rect.Perimeter())

circle := &Circle{15}
fmt.Println("Circle area:", circle.Area())
fmt.Println("Circle perimeter:", circle.Perimeter())

}

In the above code, we define a Shape interface, which contains two methods Area() and Perimeter(), which calculate The area and perimeter of a figure. Then, we defined two specific types that implement the interface through the Rectangle and Circle structures, and implemented their methods.

By utilizing method calls of interface types, we can implement the same function in different data structures, thereby achieving more flexible and scalable programming.

3. Avoid method overloading

In other programming languages, method overloading is a common mechanism by defining the same method name in the same class, but the parameter type Or different quantities to achieve different functions. However, in Go language, method overloading is not allowed, because the design principles of Go language are simplicity and clarity, and should not be too complicated.

For example, here is an error example where we try to define two methods named Print in the same struct type, but with different parameter types or numbers:

type User struct {

name   string
gender string
age    int

}

func (u *User) Print() {

fmt.Println(u.name, u.gender, u.age)

}

func (u *User) Print(msg string) {

fmt.Println(msg, u.name, u.gender, u.age)

}

In the above code, we are trying to implement two methods named Print, but with different parameter types or numbers. However, this approach is not allowed because the Go language has clear restrictions on method names and signatures, thus avoiding the complexity caused by method overloading.

4. Summary

This article deeply discusses the basic principles, grammatical rules and practical skills of method calling in Go language. By understanding this knowledge, we can better apply method calls in the Go language and achieve more efficient and flexible programming. At the same time, we must also pay attention to following the design principles of the Go language and avoid overly complex code implementation, so as to maintain the readability and maintainability of the code.

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