Is it possible to cast an int array to a char array? If so - how?
I'm currently working on a project where I need to create an char array containing the alphabet. My current code creats an int array (which should be converted to an char array - in one Line!):
return IntStream.range('a', 'z' + 1).toArray();
Yeah, we’re missing a stream method to produce a char array. Maybe a whole CharStream class. In any case, no, you cannot cast between int[] and char[].
In the meantime, it’s getting a long line, but it works:
return IntStream.rangeClosed('a', 'z')
.mapToObj(c -> Character.toString((char) c))
.collect(Collectors.joining())
.toCharArray();
This gives a char[] containing
[a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z]
IntStream.range('a', 'z' + 1) can be replaced with IntStream.rangeClosed('a', 'z')
IntStream.range('a', 'z' + 1)), but in any case, it’s clearly more readable.
From Java-11 and onwards , you can use .mapToObj(Character::toString)
instead of .mapToObj(c -> Character.toString((char) c)) , so your overall code boils down to :
return IntStream.rangeClosed('a', 'z')
.mapToObj(Character::toString)
.collect(Collectors.joining())
.toCharArray();
Let's keep it one line then:
return IntStream.range('a', 'z' + 1).mapToObj(i -> Character.valueOf((char) i)).toArray(Character[]::new);
This converts from IntStream, to Stream<Character>. Keep in mind chars and ints are essentially the same in terms of many calculations, so this step may be unnecessary (especially for comparisons).
Edit:
Fixed the above line to be functional, there is a better solution but I'm still trying to find it again. It currently returns a Character[] array.
Without the 1 line restriction it's simple to just remake the array, treating a as your 0 index.
char[] back = new char[('z' + 1) - 'a'];
IntStream.range('a', 'z' + 1).forEach(i -> back[i - 'a'] = (char) i);
return back;
object array - how can I cast it to an char array? :3
You cannot cast int array to char array because there are absolutely different types.
There are 2 possible options:
1) create a char array and copy each value from int array 2) use generic lists or collections. You can simple use it for casting
Character.forDigit(a, 10);.int[]tochar[]. Also, your current code doesn't work, so it doesn't matter how short it is. First rule of optimization: It has to work. Since Java 8 doesn't have aCharStream, you should do it with a normalforloop. It only takes 3 lines of code (4 with return statement), and it works!