如何在Golang中定义数组的切片长度？

huangapple
go评论111阅读模式
英文:

how to define length of slices into array in golang?

问题

我有一个切片数组，我想定义切片的长度，因为当我尝试运行代码时出现了恐慌：

  1. panic: runtime error: index out of range [0] with length 0

代码如下：

  1. func Transpose(m [][]int) [][]int{
  2.     arr := make([][]int, len(m))
  4.     for i:=0; i < len(arr); i++ {
  5.         for j:=0; j<len(arr); j++ {
  6.             arr[j][i] = m[i][j]
  7.         }
  8.     }
  10. return arr
  11. }
英文:

I have an array of slices and I want to define length of slices, because when I'm trying to launch a code getting the panic:

  1. panic: runtime error: index out of range [0] with length 0

the code:

  1. func Transpose(m [][]int) [][]int{
  2. 	arr := make([][]int, len(m))
  4. 	for i:=0; i &lt;len(arr); i++ {
  5. 		for j:=0; j&lt;len(arr); j++ {
  6. 			arr[j][i] = m[i][j]
  7. 		}
  8. 	}
  9. 	
  10. return arr
  11. }

答案1

得分: 3

问题在于您没有初始化每个内部切片。arr := make([][]int, len(m))只初始化了arr切片的外部循环。

  1. func Transpose(m [][]int) [][]int {
  2. 	arr := make([][]int, len(m))
  4. 	for i := 0; i < len(m); i++ {
  6. 		arr[i] = make([]int, len(m[i]))
  8. 		for j := 0; j < len(m[i]); j++ {
  9. 			arr[i][j] = m[j][i]
  10. 		}
  11. 	}
  13. 	return arr
  14. }
英文:

The issue is that you haven't initialised each inner slice. arr := make([][]int, len(m)) only initialise the outer loop of the arr slice.

  1. func Transpose(m [][]int) [][]int {
  2. 	arr := make([][]int, len(m))
  4. 	for i := 0; i &lt; len(m); i++ {
  6. 		arr[i] = make([]int, len(m[i]))
  8. 		for j := 0; j &lt; len(m[i]); j++ {
  9. 			arr[i][j] = m[j][i]
  10. 		}
  11. 	}
  13. 	return arr
  14. }

huangapple
  • 本文由 发表于 2023年6月24日 13:00:00
  • 转载请务必保留本文链接：https://go.coder-hub.com/76544626.html
  • arrays
  • go
  • slice
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