golang bailout definition method

Go language is an open source programming language that has become a very popular language, especially in the field of software development. The Go language was originally developed by Google. It has efficient compilation speed, memory allocation and coroutine mechanism, making it one of the programming languages ​​​​for modern software applications.

Method in Go language is a function type, defined on the structure type, which allows to perform specific operations on objects of specific types. In the Go language, a method is a variant of a function type. A receiver is added to the function, allowing us to call this method on an object of a specific type.

In the Go language, there are two ways to define methods: value receiver and pointer receiver. Value receivers operate on a copy of the value, while pointer receivers operate on the original value. Therefore, it is often more efficient to use a pointer receiver.

When using the Go language, in some cases, we need to define methods outside a package. This article will explore how to define out-of-package methods in Go language.

Out-of-pocket definition method

Method definitions in Go language are usually in the same package. If you want to use a method that does not belong to the same package, you must expose the method to the other package.

Methods to be exposed must have names with uppercase letters. This is a programming convention in the Go language, which means that this method is public and can be accessed by other packages.

For example:

type Person struct {
    name string
}

func (p Person) GetName() string {
    return p.name
}

In the above example, the GetName method can only be used in the package in which it is defined. If you want to use the GetName method in other packages, you need to make it public:

type Person struct {
    name string
}

func (p Person) GetName() string {
    return p.name
}

func (p *Person) SetName(name string) {
    p.name = name
}

In the above example, we defined a SetName method that uses a pointer receiver and sets the name parameter to the name of the Person structure Attributes.

The method is now accessible in external packages, and the name of the SetName method starts with a capital letter.

Similarly, if you want to expose a value type method, you also need to start the method name with a capital letter:

type Circle struct {
    x, y, r float64
}

func (c Circle) Area() float64 {
    return math.Pi * c.r * c.r
}

func (c *Circle) Scale(factor float64) {
    c.r *= factor
}

In the above example, we defined a method Area() Used to calculate the area of ​​a circle, this method is used to access the Circle structure. However, if we want external packages to access this method, we need to change its name to start with an uppercase letter:

type Circle struct {
    x, y, r float64
}

func (c Circle) Area() float64 {
    return math.Pi * c.r * c.r
}

func (c *Circle) Scale(factor float64) {
    c.r *= factor
}

func (c Circle) IsInside(x, y float64) bool {
    dx := x - c.x
    dy := y - c.y
    return dx*dx+dy*dy <= c.r*c.r
}

In the above example, we defined a new IsInside method to determine Whether a point is inside a circle. The name of this method starts with a capital letter so it can be accessed from outside the package.

The role of the bailout method

In the Go language, the bailout method plays a great role. It allows us to expose private functionality within a package so that other packages can use it.

For example, we can define a package called "Utils" that contains some private methods for processing strings. If other packages need to use these methods, we can expose them.

At the same time, using the out-of-warranty method can also separate the code logic into multiple packages, improving the readability and maintainability of the code. This can split different functional modules into independent packages, each with its own responsibilities, rather than having all the program logic mixed together.

Conclusion

The definition method of guaranteed methods in Go language is relatively simple. Just prepend the method name with a capital letter to make it public and accessible to other packages. This greatly improves code reusability and maintainability. At the same time, it also makes the code more modular and makes different functional modules more independent and composable.

The above is the detailed content of golang bailout definition method. For more information, please follow other related articles on the PHP Chinese website!