Go的功能和方法有什么区别？ [英] Whats the difference of functions and methods in Go?

问题描述

我试图开始使用Go，文档非常好。我在文档中找不到的是函数和方法之间的区别。

据我现在了解：函数是全局的，这意味着我做不需要导入一个包来使用函数，它们总是在那里。方法绑定到包。这是正确的吗？

解决方案

据我现在了解：函数是全局 ，这意味着我不必导入包来使用函数，它们总是在那里。方法绑定到包。这是正确的吗？

不，那是不正确的。 内置软件包中的一些功能始终可用。其他所有内容都需要导入。

术语方法提出了面向对象编程。在OOP语言中（例如C ++），您可以定义一个类来封装属于一起的数据和函数。这些类中的函数称为方法，您需要该类的实例来调用这样的方法。

在Go中，术语基本相同，尽管Go不是古典意义上的OOP语言。在Go中，一个接收器的函数通常称为方法（可能仅仅是因为人们仍然习惯于OOP的术语）。

所以，例如： / p>

  func MyFunction（a，b int）int {
返回a + b 
} 
 //用法：
 // MyFunction（1，2）
  

但是

 类型MyInteger int 
 func（a MyInteger）MyMethod（b int）int {
 return a + b 
} 
 //用法：
 // var x MyInteger = 1 
 // x.MyMethod（2）
  

I am trying to get started with Go and the documentation is very good. What I did not find in the documentation is the difference between functions and methods.

As far as I understand at the moment: functions are "global", which means I do not have to import a package to use functions, they are always there. Methods are bound to packages. Is this correct?

解决方案

As far as I understand at the moment: functions are "global", which means I do not have to import a package to use functions, they are always there. Methods are bound to packages. Is this correct?

No, that's not correct. There are just a couple of functions from the builtin package which are always available. Everything else needs to be imported.

The term "method" came up with object-oriented programming. In an OOP language (like C++ for example) you can define a "class" which encapsulates data and functions which belong together. Those functions inside a class are called "methods" and you need an instance of that class to call such a method.

In Go, the terminology is basically the same, although Go isn't an OOP language in the classical meaning. In Go, a function which takes a receiver is usually called a method (probably just because people are still used to the terminology of OOP).

So, for example:

func MyFunction(a, b int) int {
  return a + b
}
// Usage:
// MyFunction(1, 2)

but

type MyInteger int
func (a MyInteger) MyMethod(b int) int {
  return a + b
}
// Usage:
// var x MyInteger = 1
// x.MyMethod(2)

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