Single character String

Question

My opinion was, until today, that a literal like "c" creates a String object. Today I heard that Java is not creating an object for single character strings. Is this right? Does it store that literal as a char?

Answer 1

No it's wrong. Even "", creates a String object. However if you type 'c', you got a char and not a String object.

Answer 2

"c" will create a string. 'c' will create a char

Answer 3

Java does create an instance of a string even for a single character string. The following prints java.lang.String:

public class Test{
    public static void main(final String[] args){
        System.out.println("c".getClass().getName());
    }
}

Answer 4

"c" is a String literal. It represents a String just as "foo" represents a String.

There is no special handling of single-character String literals (not even of the 0-letter String literal "").

Whoever told you that it's treated differently was either a.) wrong or b.) talking about something different (a library that has special treatment, for example).

Answer 5

"c" does create an object. However, if you assign the literal again in somewhere in the source code, it will not create a new object, but reference the first string object created.

For example:

String s1 = "abc";   //creates the String object
String s2 = "abc";   //references the same object as s1

Both s1 and s2 are assigned the same object, and == would work.

You can read more here: http://javatechniques.com/blog/string-equality-and-interning/

Answer 6

Maybe what was meant was that the beneath the hood flyweights are created (dunno how this works with Java, but I presume that this concept is employeed at some level for strings)