Does Java define constants for any characters such as SPACE?

Question

Does Java include any constants for single characters such as SPACE?

Having names taken from Unicode would be handy when doing string manipulations.

I want this:

String musician = "Lisa" + Character.SPACE + "Coleman" ;

…rather than this:

String musician = "Lisa" + " " + "Coleman" ;

(not to be confused with the java.lang.Character class)

If nothing bundled with Java, alternatives?

Answer 1

There are some in Apache Commons

org.apache.commons.lang3.StringUtils.SPACE

more

Answer 2

There is no such constant, and for good reasons, IMO.

Why use a constant in the first place in your example?

String musician = "Lisa" + Character.SPACE + "Coleman" ;

is less readable than

String musician = "Lisa Coleman";

or even than

String musician = "Lisa" + ' ' + "Coleman";

So I guess it's not for readability reasons.

I thus guess that you want a constant to avoid repeating yourself in several portions of code. But using Character.SPACE instead of ' ' everywhere doesn't lead to less repetitions. Only to more verbose and less readable code.

I thus guess that you want to be able to change the constant value in one place, and have it changed everywhere it's used. But then using a built-in Character.SPACE constant wouldn't allow you achieveing that goal. You would still need your own constant, and its name shouldn't be what the value is, but what the value is for:

private static final char FIRST_NAME_LAST_NAME_SEPARATOR = ' ';

Now, there is a good reason to use that constant: if you later decide to use a tab instead of a space, you can change the value of the constant and recompile all your code.

Answer 3

Java does have a list of character constants used to substitute "untypeable" characters such as a backspace (represented by \r). the full list can be found at https://docstore.mik.ua/orelly/java-ent/jenut/ch10_05.htm However here is a few examples:

\\      Backslash
\r      Carriage Return
\"      Double Quote (same for single Quote)
\n      Newline

You get the idea. Hope this is what you were looking for since you did mention character constants in your title.

Edit: When using character constants as characters surround them with single quotes rather than double quotes. Despite being two (or more) characters long they denote a single character or a single binary digit rather than a string.

Note: When attempting to compare the 'enter' character in the java.awt.event.KeyListener keyTyped function the \n character constant should be user rather than the \r character constant.