Java中String二维数组转换char二维数组

写leetcode37.解数独算法的时候想用测试用例，结果发现测试用例都是字符串如图

输入：board = [["5","3",".",".","7",".",".",".","."],
			   ["6",".",".","1","9","5",".",".","."],
			   [".","9","8",".",".",".",".","6","."],
			   ["8",".",".",".","6",".",".",".","3"],
			   ["4",".",".","8",".","3",".",".","1"],
			   ["7",".",".",".","2",".",".",".","6"],
			   [".","6",".",".",".",".","2","8","."],
			   [".",".",".","4","1","9",".",".","5"],
			   [".",".",".",".","8",".",".","7","9"]]

然后题目开始又是传入char[][]类型的（也可以把参数变成String[][]，就不）

class Solution {
    public void solveSudoku(char[][] board) {

    }
}

然后搜了一下网上也没有，于是乎就想弄一个偷懒下次使用也方便的方发

public static char[][] string2ToChar2(String[][] board) {
    char[][] chars = new char[board.length][board.length];
    for (int i = 0; i < board.length; i++) {
        for (int j = 0; j < board.length; j++) {
            chars[i][j] = board[i][j].charAt(0);
        }
    }
    return chars;
}

public static void main(String[] args) {
    String[][] board = {{"5","3",".",".","7",".",".",".","."},
                        {"6",".",".","1","9","5",".",".","."},
                        {".","9","8",".",".",".",".","6","."},
                        {"8",".",".",".","6",".",".",".","3"},
                        {"4",".",".","8",".","3",".",".","1"},
                        {"7",".",".",".","2",".",".",".","6"},
                        {".","6",".",".",".",".","2","8","."},
                        {".",".",".","4","1","9",".",".","5"},
                        {".",".",".",".","8",".",".","7","9"}};
    char[][] chars = string2ToChar2(board);
    System.out.println("=========验证==========");
    for (int i = 0; i < chars.length; i++) {
        for (int j = 0; j < chars.length; j++) {
            System.out.print(chars[i][j]);
        }
        System.out.println();
    }

}

测试结果