Re: learning Java

[David Gibbs <david@xxxxxxxxxxxx>]

At 10:47 AM 04/15/2000 , you wrote:
>1. String x = "100"; String y = "100"; if (x == y) {};
>      In this case I thought x would not equal y since they refer to
>different
>      objects and different memory locations. The book says that they do
>      match because the compiler re-uses the same String object if it sees
>      the contents match. Is this true only for String objects or other
>objects
>      treated the same way? Is this true for only String objects in the same
>      class or does this optimization occur across classes?

I'm not sure this is true ... I'll have to research

>  2. String x = "abc"; String y = "abc"; x  += "def";
>      I assume that after the first two statements, both x and y point to the
>      same memory location. After the third statement, there are actually
>      two objects with different memory locations (x being "abcdef" and y
>      being "abc").

Java won't reuse the same object for x, regardless of y's value ... when 
you do the assignment, you would be creating a new x object.

david


--
| Internet: david@midrange.com
| WWW:      http://www.midrange.com/david
|
| This message was written and delivered using 100%
| post-consumer (recycled) data bits.

+---
| This is the JAVA/400 Mailing List!
| To submit a new message, send your mail to JAVA400-L@midrange.com.
| To subscribe to this list send email to JAVA400-L-SUB@midrange.com.
| To unsubscribe from this list send email to JAVA400-L-UNSUB@midrange.com.
| Questions should be directed to the list owner: joe@zappie.net
+---