Casting int to char in Java

Question

I'm looking for a straightforward answer and can't seem to find one.

I'm just trying to see if the following is valid. I want to take the integer 7 and turn it into the character '7'. Is this allowed:

int digit = 7;
char code = (char) digit;

Thank you in advance for your help!

Integer is not the same as int and Character is not the same as char. Also try it and see if it works. — Nico, Mar 24 '14 at 20:58
This might be useful for you: http://stackoverflow.com/questions/17984975/convert-int-to-char-in-java — Thibstars, Mar 24 '14 at 21:03
Simply trying this yourself and outputting the result to the console would answer this question. — aliteralmind, Mar 24 '14 at 21:03

rgettman · Answer 1 · 2014-03-24T21:05:59.503

4

This conversion is allowed, but the result won't be what you expect, because char 7 is the bell character whereas '7' is 55 (0x37). Because the numeric characters are in order, starting with '0' at 48 (0x30), just add '0', then cast the result as a char.

char code = (char) (digit + '0');

You may also take a look at the Unicode characters, of which the printable ASCII characters are the same codes.

edited Mar 24 '14 at 21:05

answered Mar 24 '14 at 21:00

rgettman

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Argh, why point to ASCII when there is Unicode and Java does Unicode? :p – fge Mar 24 '14 at 21:01
See my answer as to why refering to ascii is imho not a good thing – fge Mar 24 '14 at 21:15

score 1 · Answer 2 · answered Mar 24 '14 at 21:05

'7' is Unicode code point U+0037.

Since it is a code point in the Basic Multiligual Plane, and since char is a UTF-16 code unit and that there is a one-to-one mapping between Unicode code points in this plane and UTF-16 code units, you can rely on this:

(char) ('0' + digit)

Do NOT think of '7' as ASCII 55 because that prevents a good understanding of char... For more details, see here.

score 1 · Answer 3 · answered Mar 24 '14 at 21:12

1

Nope. The char '7' can be retrieved from int 7 in these ways:

 int digit = 7;
 char code = Integer.toString(digit).charAt(0);
 code = Character.forDigit(digit, 10);

answered Mar 24 '14 at 21:12

andy

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score 0 · Answer 4 · answered Mar 24 '14 at 21:01

0

If digit is between 0 and 9:

int digit = 7;
char code = (char)(((int)'0')+digit);

answered Mar 24 '14 at 21:01

user2693979

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No need to explicitly widen `'0'` to `int`. – Marko Topolnik Mar 24 '14 at 21:05

Casting int to char in Java

4 Answers4