Go中的结构初始化和方法声明

Question

我是 Go 的新手，对结构非常好奇。让我们定义一个结构 T

type T struct {
    size int
}

1. 我见过不同类型的结构初始化。有什么区别？

   new(T)     // 1
   T{size:1}  // 2
   &T{size:1} // 3
   

2. 以及两种类型的方法声明:

   func (r *T) area() int // 1
   func (r T) area() int  // 2
   

   正确的方法应该是什么？

Answer 1

1. 分配

new 和 &T{size:1} 返回 *T

T{size:1} 返回 T

The built-in function new takes a type T, allocates storage for a variable of that type at run time, and returns a value of type *T pointing to it. The variable is initialized as described in the section on initial values.

2.

The method set of any other named type T consists of all methods with receiver type T. The method set of the corresponding pointer type *T is the set of all methods with receiver *T or T (that is, it also contains the method set of T).

变量 pt *T

变种人

func (r *T) area() int

你可以使用 pt.area() 或 t.area()

func (r T) area() int

可以用t.area()，不能用pt.area()

通常我们使用 func(r *T) area() int