What is the Character equivalent of the String "" (blank String)?

Question

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How to represent empty char in Java Character class

I am using the replace function as defined in java.lang.String, and I tried using "\0" as the equivalent for "" (blank String) but it adds a space not a blank string.

Is there a Character equivalent for a blank String?

http://stackoverflow.com/questions/8534178/how-to-represent-empty-char-in-java-character-class — vtsatskin, Nov 09 '12 at 05:44
What is the code you're running? Are you just trying to delete parts that match your regular expression? — Ruan Mendes, Nov 09 '12 at 05:46
Can you please post your code here ? So we can know what you are trying to do. — Shamis Shukoor, Nov 09 '12 at 05:46
Your string don't contains characters. That means you can't get equivalent. — Damask, Nov 09 '12 at 05:46

score 6 · Accepted Answer · answered Nov 09 '12 at 05:48

There is no such thing as an "empty character". A char is a value-type, so it has to have a value. An absence of a value is the absence of a char - which is why you can have empty strings (i.e. "no characters") and a nullable char, but not an "empty char".

Anyway, the String.replace(char, char) method is meant to substitute one character for another. This operation is very simple because it means that a single block of known size has to be allocated. Whereas String.replaceAll(string,string) is a considerably more complicated method to implement, which is why they're different.

Unfortunately there is no String.replace(char,string) method - but I hope you can understand why.

I understand now. Maybe I should try a different method than String.replace(char, char). — hologram, Nov 09 '12 at 05:50

score 1 · Answer 2 · answered Nov 09 '12 at 05:44

1

There are infinitely many blank Strings in a given String... how many "nothings" are between 'a' and 'b' in "ab"? It's like dividing by zero!

answered Nov 09 '12 at 05:44

durron597

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score 1 · Answer 3 · answered Nov 09 '12 at 05:49

I supose you want to replace "something" with "", you can't do it the other way around...

       String ou="test";
       ou = ou.replace("t", "");
       System.out.println(ou);

the output will be: es

with the char version of replace this will not work as '' is not a valid char.

score 1 · Answer 4 · answered Nov 09 '12 at 05:53

You can't use String.replace(char,char) if you want to remove characters. There is no empty character. That method will never change the length of the string, it just replaces a character with another character

You have to use String.replaceAll(java.lang.String, java.lang.String) (or replaceFirst)

"ababababa".replaceAll("a", ""); // returns "bbbb"

score 0 · Answer 5 · edited Nov 09 '12 at 05:47

0

There isn't, but notice that there is a String.replace(CharSequence, CharSequence), so you should be able to call String.replace with a string as the first argument and "" as the second argument.

edited Nov 09 '12 at 05:47

Sumit Singh

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answered Nov 09 '12 at 05:46

osandov

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What is the Character equivalent of the String "" (blank String)?

5 Answers5