golang三种实例化方式

发布时间:2024-10-01 13:16:00

Introduction

Go (also known as Golang) is an open-source programming language that was created at Google in 2007. It is designed to be efficient, expressive, and easy to use. One of the unique features of Go is its simplicity, which extends to its object-oriented programming model. In this article, we will explore the three ways to instantiate objects in Go.

Method 1: Using a Struct Literal

In Go, structures (structs) are used to define objects. One way to instantiate an object is by using a struct literal. A struct literal allows you to create an instance of a struct by specifying the values of its fields.

For example, let's say we have a struct definition for a person:

type Person struct {
    Name string
    Age  int
}

To create an instance of a person using a struct literal, we can do the following:

person := Person{
    Name: "John Doe",
    Age:  30,
}

In this example, we create a new person object and assign it to the variable "person". We set the "Name" field to "John Doe" and the "Age" field to 30.

Method 2: Using the "new" Keyword

In Go, the "new" keyword is another way to instantiate objects. Unlike a struct literal, the "new" keyword initializes the fields of the object to their zero values.

Here's how we can use the "new" keyword to create a new person object:

person := new(Person)

In this case, the "person" variable is initialized with a new allocated zero-initialized person object. The "Name" field will be an empty string, and the "Age" field will be set to 0.

Method 3: Using a Constructor Function

The third way to instantiate objects in Go is by using a constructor function. A constructor function is a special function that returns a newly created object.

Here's an example of a constructor function for a person object:

func NewPerson(name string, age int) *Person {
    return &Person{
        Name: name,
        Age:  age,
    }
}

We can use the constructor function to create a new person object as follows:

person := NewPerson("John Doe", 30)

In this case, the constructor function takes two arguments, "name" and "age", and returns a pointer to a newly created person object with the specified values for its fields.

Conclusion