【Go structs、slices、maps】

1、定义时*在变量名后面，使用时*在变量名前面。

2、定义struct，type在前，struct关键字在后。

3、指针可以指定struct。

4、A struct literal denotes a newly allocated struct value by listing the values of its fields.

　　You can list just a subset of fields by using the Name: syntax. (And the order of named fields is irrelevant.)

5、array定义。

6、A slice points to an array of values and also includes a length.

　　[]T is a slice with elements of type T.

7、Slices can be re-sliced, creating a new slice value that points to the same array.

　　[a,b]取值区间为a->b-1。

8、Making slices

9、The zero value of a slice is nil.

　　A nil slice has a length and capacity of 0.

　　对于上式，z是nil.

10、通过append方法添加元素。

11、range在for中可用来迭代slices。

12、通过_可以略去索引。

13、Maps must be created with make (not new) before use

14、Map literals are like struct literals, but the keys are required.

15、可以省略Vertex。If the top-level type is just a type name, you can omit it from the elements of the literal.

16、map的操作

17、函数也是一个变量。

18、closure。

参考：https://tour.golang.org/moretypes/1