在golang中创建二维字符串数组

Question

I need to create a 2 dimensional string array as shown below -

matrix = [['cat,'cat','cat'],['dog','dog']]

Code:-

package main

import (
    "fmt"
)

func main() {
    { // using append

    var matrix [][]string
    matrix[0] = append(matrix[0],'cat')
        fmt.Println(matrix)
    }
}

Error:-

panic: runtime error: index out of range

goroutine 1 [running]:
main.main()
    /tmp/sandbox863026592/main.go:11 +0x20

Answer 1

You have a slice of slices, and the outer slice is nil until it's initialized:

matrix := make([][]string, 1)
matrix[0] = append(matrix[0],'cat')
fmt.Println(matrix)

Or:

var matrix [][]string
matrix = append(matrix, []string{"cat"})
fmt.Println(matrix)

Or:

var matrix [][]string
var row []string
row = append(row, "cat")
matrix = append(matrix, row)