Create a global bidimensional slice with length taken in input-CodePudding

I need to create a bidimensional slice with a custom length, taken in input. The slice is the field of my minesweeper, so the length will be the dimension of the field. I need the slice to be global, right now I inizialize the slice directly to the costant dimension of the field, but I am implementing the difficulty, so I need the field to be variable.

//my code right now
const dimX int = 16            //X field dimension
const dimY int = 16            //Y field dimension
var bombs int = 40             //number of mines
var number [dimX][dimY]int8    //number contained in the cell, 0 if empty, -1 if mine
var isOpen [dimX][dimY]bool    //if the cell is visible to the user
var isFlagged [dimX][dimY]bool //if the cell is marked as a bomb

Is there a way I can declare the variables and then initialize them in a function, something like this (that way is obv not possible in go):

//what i'd like to do
var dimX, dimY, bombs int
var number [][]int8
    
func main() {
   Scan(&dimX, &dimY, &bombs)
   number = [dimX][dimY]
   ...
}

I tried also something with make, but it gives me an incompatible assign (cannot use make([][]uint8, dimX) (value of type [][]uint8) as [16][16]int8):

func main() {
   Scan(&dimX, &dimY, &bombs)
   number = make([][]uint8, dimX)
   for i := range number {
      number[i] = make([]uint8, dimY)
   }
   ...
}

The only way I found is viable is via the append() function: declare the field to [][] or [0][0] and after the user input run a function that append() x times and y times to the slice

CodePudding user response：

The first snippet of code in the question uses an array of arrays. The length of an array is set at compile time.

Use a slice of slices as in the second snippet of code. The length of a slice is dynamic.

Allocate the slices with make as shown in the third snippet of code.

var dimX, dimY, bombs int
var number [][]int8  // empty [] is a slice.

fmt.Scan(&dimX, &dimY, &bombs)
number = make([][]int8, dimX)
for i := range number {
    number[i] = make([]int8, dimY)
}

Note: The code in the question uses int8 and uint8 when referring to the elements. These are different types. This answer uses int8.

Run the example on the playground.