是否可以将String转换为int数组？

Question

I've written that piece of code in which I scanned an integer suppose 121 and for dividing it into 3 part I make it a String and tried to convert it again by splitting.But I am not getting the way? Is there any simple way to make it so?

  public static void main(String []args){
      Scanner scan = new Scanner(System.in);
      int n = scan.nextInt() ;
      int sum = 0;
      for(int i = 1 ; i<=n; i++){
         String s = Integer.toString(i);

          int[] c = Integer.parseInt(s.split("")); //Here's the problem
          int sm = 0 ;
          for(int x :c){
              sm +=x ;
          }
          System.out.print(sm+" ");
       }
   }

input = 12

expected output: 1 2 3 4 5 6 7 8 9 1 2 3

output : Main.java:14: error: incompatible types: String[] cannot be converted to String int[] c = Integer.parseInt(s.split(""));

Answer 1

Your expected output would not even seem to need any integer to string conversion:

int n = scan.nextInt();
for (int i=0; i < n; i++) {
    if (i > 0) System.out.print(" ");
    System.out.print(1 + i % 9);
}

For an input of n = 12 , this prints:

1 2 3 4 5 6 7 8 9 1 2 3

Answer 2

You can't pass the whole array to parseInt() . You need to parse each element individually:

int[] c = Arrays.stream(s.split(""))
        .mapToInt(Integer::parseInt)
        .toArray();

Or the old-fashioned way:

String[] chars = s.split("");
int[] c = new int[chars.length];
for (int i = 0; i < c.length; i++) {
    c[i] = Integer.parseInt(chars[i]);
}

Answer 3

You could map each character from the String[] (from the split ) to an int , and then convert that to an int[] . Like,

int[] c = Arrays.stream(s.split("")).mapToInt(Integer::parseInt).toArray();

with no other changes, that produces (as requested)

1 2 3 4 5 6 7 8 9 1 2 3 

With input of "12".

Answer 4

You can also do it like this using an IntStream.

    int n = 12;
    int[] values = IntStream.range(0, n).map(i -> i % 9 + 1).toArray();
    System.out.println(Arrays.toString(values));

Produces

[1 2 3 4 5 6 7 8 9 1 2 3]

for n = 12