Splitting strings by characters

Nekios

I want to write a function which take strings as input and returns an array of characters consisting of the characters in the order they originally appear in the string. For example, explode( "Dirk" ) should return the array {'D', 'i', 'r', 'k'}. However, I cannot get it to work.

char[] explode(String s) { String theString = s; char[] c = new char[theString.length()]; for (int i = 0; i < theString.length(); i++) { c[i] = theString.charAt(i); return c[i]; } }

I also want to write a function that behaves like the above one in reverse. Taking an array of characters as input and returns a String consisting of all the characters in the array glued together. For example, returning ("Dirk") after inputting the array {'D', 'i', 'r', 'k'}.

GoToLoop

https://forum.Processing.org/two/discussion/15473/readme-how-to-format-code-and-text

http://docs.Oracle.com/javase/8/docs/api/java/lang/String.html#toCharArray--

https://forum.Processing.org/two/discussions/tagged?Tag=tochararray()

Chrisir

Your line with return must be outside the for loop, after }

and return c;

EDITED

Lord_of_the_Galaxy

The second part is simple-

char[] data = {'a', 'b'};
String joined = new String(data);

jeremydouglass

@Nekios -- The easiest way is to use toCharArray, as @GoToLoop suggests. This example sketch gives two examples, running on a String variable or directly on a String in-place:

String theString = "Dirk";

for (char ch: theString.toCharArray()) {
  println(ch);
}

for (char ch: "Gently".toCharArray()) {
  println(ch);
}

For more discussion, see:

• http://stackoverflow.com/questions/2451650/how-do-i-apply-the-for-each-loop-to-every-character-in-a-string

Chrisir

    void setup() {

      printArray(explode("Dirk"));
    }

    char[] explode(String s) { // function explode

      String theString = s;
      char[] c = new char[theString.length()];

      for (int i = 0; i < theString.length(); i++) {
        c[i] = theString.charAt(i);
      }
      return c;
    }

jeremydouglass

Addendum -- you asked about the reverse case. It is extremely simple -- just use the String constructor:

char[] c = {'D', 'i', 'r', 'k'};
String theString = new String(c);

HOWEVER, see this discussion...

• http://stackoverflow.com/questions/7655127/how-to-convert-a-char-array-back-to-a-string

...and in particular:

Because String is handled specially in Java, even "foo" is actually a String. So the need for splitting a String into individual chars and join them back is not required in normal code.

In general, don't bother with all this converting and reconverting back. Your String is already a charArray in effect, and individual chars can be accessed (or looped through) at any time.