Integer printing wrong value

Question

When converting an integer to int array, for example 123 to {1,2,3}, I am getting values {49,50,51}. Not able to find what is wrong with my code.

public class Test {
    public static void main(String [] args) {
        String temp = Integer.toString(123);
        int[] newGuess = new int[temp.length()];
        for (int i = 0; i < temp.length(); i++) {
            newGuess[i] = temp.charAt(i);
        }
        for (int i : newGuess) {
            System.out.println(i);
        }
    }
}

Output:

49

50

51

Answer 1

charAt(i) will give you UTF-16 code unit value of the integer for example in your case, UTF-16 code unit value of 1 is 49. To get integer representation of the value, you can subtract '0'(UTF-16 code unit value 48) from i.

public class Test {
    public static void main(String [] args) {
        String temp = Integer.toString(123);
        int[] newGuess = new int[temp.length()];
        for (int i = 0; i < temp.length(); i++) {
            newGuess[i] = temp.charAt(i);
        }
        for (int i : newGuess) {
            System.out.println(i - '0');
        }
    }
}

Output:

1

2

3

Answer 2

temp.charAt(i) is basically returning you characters. You need to extract the Integer value out of it.

You can use:

newGuess[i] = Character.getNumericValue(temp.charAt(i));

Output

1
2
3

Code

public class Test {
    public static void main(String [] args) {
        String temp = Integer.toString(123);
        int[] newGuess = new int[temp.length()];
        for (int i = 0; i < temp.length(); i++) {
            newGuess[i] = Character.getNumericValue(temp.charAt(i));
        }
        for (int i : newGuess) {
            System.out.println(i);
        }
    }
}

Answer 3

To add a little Java 8 niceties to the mix which allows us to pack everything up neatly, you can optionally do:

int i = 123;
int[] nums = Arrays.stream(String.valueOf(i).split(""))
        .mapToInt(Integer::parseInt)
        .toArray();

Here we get a stream to an array of strings created by splitting the string value of the given integer's numbers. We then map those into integer values with Integer#parseInt into an IntStream and then finally make that into an array.

Answer 4

As your interest is to get as an integer value of an string. Use the method parse int Integer.parseInt() . this will return as integer. Example : int x =Integer.parseInt("6"); It will return integer 6.