arrays - 如何使用for循环遍历2D数组

Question

package main

import (
    "fmt"
)

func main() {
    grid := [][]int{
        {0, 1, 2, 3},
        {4, 5, 6, 7},
    }
    for _, array := range grid[0] {
        for j := range array {
            fmt.Print(array[j], " ")
        }
        fmt.Println()

    }
}

这就是我现在拥有的内容，我试图遍历每一列，但是出现编译错误以下

./prog.go:13:12: cannot range over array (type int)

grid是[] [] int数组。我正在尝试将数组设置为每一列并遍历该列。

PlayGround

Answer 1

似乎您的内部range中缺少一个变量名。

从https://tour.golang.org/moretypes/16:

When ranging over a slice, two values are returned for each iteration. The first is the index, and the second is a copy of the element at that index.

下面的代码已修复(可运行示例 https://play.golang.org/p/6uaM2IEm9lR)

package main

import (
    "fmt"
)

func main() {
    grid := [][]int{
        {0, 1, 2, 3},
        {4, 5, 6, 7},
    }
    for _, col := range grid {
        for _, value := range col {
            fmt.Println(value)
        }
    }
}