Name: jl125535 Date: 11/25/2003


URL OF FAULTY DOCUMENTATION :
http://java.sun.com/j2se/1.4.2/docs/api/java/lang/StringBuffer.html

A DESCRIPTION OF THE PROBLEM :
The documentation for StringBuffer contains:

For example, the code:
x = "a" + 4 + "c" is compiled to the equivalent of: x = new StringBuffer().append("a").append(4).append("c").toString()

This is not correct.
"a" + 4 + "c" is a concatenation of constants, and so the concatenation is done at compile time (JLS - 3.10.5 String Literals at http://java.sun.com/docs/books/jls/second_edition/html/lexical.doc.html#101083):
("a" + 4 + "c") == "a4c"
System.out.println(("a" + 4 + "c") == "a4c");

Since this is the case, x = "a" + 4 + "c", concatenation occurs at compile time, the code is not the equivalent of x = new StringBuffer().append("a").append(4).append("c").toString().

Sure the final result is the same (a String variable x has the value "a4c"), but the two methods of getting there are not equivalent.
(Incident Review ID: 185550)
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