代码的完整性：打印1到最大的n位数

public class Main {
public static void main(String[] args) {
Main test = new Main();
int n = 4;
int[] arr = new int
;
test.PrintMaxOfNDigits(arr, 0);
}

private void PrintMaxOfNDigits(int[] arr, int index) {
if (index == arr.length - 1) {
for (int i = 0; i < 10; i++) {
arr[index] = i;
PrintNumber(arr);
}
return;
}
for (int i = 0; i < 10; i++) {
arr[index] = i;
PrintMaxOfNDigits(arr, index + 1);
}

}

private void PrintNumber(int[] arr) {
int i = 0;
while (arr[i] == 0) {
i++;
if (i == arr.length) {
return;
}
}
for (; i < arr.length; i++) {
System.out.print(arr[i]);
}
System.out.print("\t");
}

}