Detailed introduction to method calling in Golang

Golang is an increasingly popular programming language favored by developers for its simplicity and efficiency. Golang provides good concurrency support and excellent performance at the language level, which makes it a good choice for building high-performance applications, services, frameworks and libraries. In Golang, we can use various ways to call functions and methods. This article will introduce method calling in Golang in detail.

1. Overview of method calling

In Golang, method calling refers to calling a method on a structure type (or its pointer type). The syntax of methods and functions is very similar, but their semantics are different. A method in Golang can be regarded as a function attached to a type, so the method must be defined on a certain type, while the function is defined in the global namespace.

In Golang, we implement method invocation by defining a method receiver. The receiver can be a structure type or its pointer type. Generally, we can define the receiver in the following way:

func (receiver_type) method_name(parameters) return_type {

//函数实现

}

where receiver_type specifies the receiver The type, method_name is the name of the method, parameters is the parameter list of the method, and return_type is the return value type of the method.

2. Method calling of structure type

The following is a simple example that demonstrates how to define and call methods on a structure type:

type Employee struct {

name   string
salary int

}

func (e Employee) displaySalary() {

fmt.Printf("Salary of %s is %d\n", e.name, e.salary)

}

func main() {

emp := Employee{name: "Jade", salary: 5000}
emp.displaySalary()

}

In the above example, we define a structure type named Employee and define a displaySalary method, which is used to print out the salary information of a given Employee. In the main function, we instantiate an Employee object and then call the displaySalary method to display its salary information.

The output result is:

Salary of Jade is 5000

This example is simple, but it demonstrates the basic concept of method calling in Golang. We have defined a method with receiver type as Employee and used it in the main function by calling the method on the Employee object.

3. Method call of structure pointer type

In the above example, we defined a method with a receiver type of Employee, which is an instance of the structure type. However, in pointer-based semantics, we often need to define and use pointer types pointing to structures, so in Golang, we can also define and call methods on structure pointers.

The following is an example demonstrating how to define and call methods on a structure pointer:

type Employee struct {

name   string
salary int

}

func (e *Employee) displaySalary() {

fmt.Printf("Salary of %s is %d\n", e.name, e.salary)

}

func main() {

emp := &Employee{name: "Jade", salary: 5000}
emp.displaySalary()

}

In the above example, we will The type is changed to a pointer to the Employee structure. We define a method called displaySalary and use a pointer to Employee as its receiver. In the main function, we instantiate a pointer to the Employee object and call the displaySalary method through the pointer to display its salary information.

The output is:

Salary of Jade is 5000

This example is very similar to the above example, but it demonstrates the use of pointer-based semantics in Golang to define and the method of calling the method.

4. Define and call methods in the interface

The interface in Golang is a type that describes the behavior of the object rather than the data. An interface can define a set of methods that focus on the behavior of the object rather than the object's implementation. Interfaces are an important part of Golang because they provide a way to define and implement polymorphism.

Here is an example that demonstrates how to define and call methods in an interface:

type SalaryCalculator interface {

displaySalary()

}

type Employee struct {

name   string
salary int

}

func (e Employee) displaySalary() {

fmt.Printf("Salary of %s is %d\n", e.name, e.salary)

}

func main() {

emp := Employee{name: "Jade", salary: 5000}
var empSalary SalaryCalculator = emp
empSalary.displaySalary()

}

In the above example, we define an interface SalaryCalculator, which defines a displaySalary method. We also defined an Employee structure type and used the displaySalary method to print the Employee's salary information.

In the main function, we instantiate an Employee object and then assign it to the interface type SalaryCalculator. Next, we use the SalaryCalculator interface to call the displaySalary method. Golang will find the implementation of this method in the implementation of the Employee type and execute it.

The output result is:

Salary of Jade is 5000

This example demonstrates how to define and use methods in the interface. It shows that we can define a method in an interface and call the method on the interface type.

5. Summary

This article introduces various ways to define and call methods in Golang. We have seen how to define and call methods on struct types and pointer types, and how to define and use methods on interface types. Whether you're a beginner or an experienced developer, you'll get some useful tips and takeaways.

In short, Golang is a very powerful programming language with concise and efficient syntax, good concurrency support and excellent performance. When using method calls, we can go from simple struct type calls to complex interface type calls, which makes Golang ideal for building high-performance applications and services. I hope this article can help you better understand method calling in Golang.

The above is the detailed content of Detailed introduction to method calling in Golang. For more information, please follow other related articles on the PHP Chinese website!