golang 我在 println() 之后使用 fmt.Println() 但是

Question

这是我的代码(golang)

func main() {
    names := []string{"1", "2", "3"}

    for index, name := range names {
        println(index, name)
    }

    myMap := map[string]string{
        "A": "Apple",
        "B": "Banana",
        "C": "Charlie",
    }

    for key, val := range myMap {
        fmt.Println(key, val)
    }
}

这是结果

0 1
B Banana
1 2
2 3
C Charlie
A Apple

1. 为什么 names 和 myMap 混在一起了？
2. 为什么 myMap 的顺序不同？

Answer 1

func println

func println(args ...Type)

The println built-in function formats its arguments in an implementation-specific way and writes the result to standard error.

func Println

func Println(a ...interface{}) (n int, err error)

fmt.Println formats using the default formats for its operands and writes to standard output.

fmt.Println 写入标准输出 (stdout) 和 println 写入标准错误 (stderr)，两个不同的非同步文件。

Map types

A map is an unordered group of elements of one type, called the element type, indexed by a set of unique keys of another type, called the key type.

For statements

A "for" statement specifies repeated execution of a block.

The iteration order over maps is not specified and is not guaranteed to be the same from one iteration to the next.

map 元素是无序的。未指定迭代顺序。