arrays - 数组和 slice 数据类型

Question

我发现自己对 array 和 slice 数据类型感到困惑。

在 Go 文档中，数组描述如下:

There are major differences between the ways arrays work in Go and C. In Go,

• Arrays are values. Assigning one array to another copies all the elements.
• In particular, if you pass an array to a function, it will receive a copy of the array, not a pointer to it.
• The size of an array is part of its type. The types [10]int and [20]int are distinct.

功能:

As in all languages in the C family, everything in Go is passed by value. That is, a function always gets a copy of the thing being passed, as if there were an assignment statement assigning the value to the parameter. For instance, passing an int value to a function makes a copy of the int, and passing a pointer value makes a copy of the pointer, but not the data it points to.

为什么 sort.Ints(arrayValue) 在我将传递的变量声明为数组而不是 slice 时会修改它？

代码

var av = []int{1,5,2,3,7}

fmt.Println(av)
sort.Ints(av)
fmt.Println(av)
return

输出

[1 5 2 3 7]
[1 2 3 5 7]

Answer 1

参见“Slices: usage and internals”

var av = []int{1,5,2,3,7}

这是一个 slice ，而不是一个数组。

A slice literal is declared just like an array literal, except you leave out the element count.

这就解释了为什么排序函数会修改 slice 所引用内容的内容。

正如下面 Kirk 所评论的那样, sort.Ints如果您将数组而不是 slice 传递给它，则会给您一个错误。

func Ints(a []int)