java can't compare strings

Question

i'm written a code that reads a line from the socket.
if the line is "bye" i want it to output "nice". from some reason it doesn't work, although i did try to output the input with no conditions and it did says "bye"

this is my code

                String input = null;
                if (socket.getInputStream().available() > 0)                    
                    input = in.readLine();                                                                  

                if (input != null)
                {
                    input = input.trim();
                    if (input == "bye")
                        out.println("nice");

                    out.println(input);
                }

possible duplicate of [Java String.equals versus ==](http://stackoverflow.com/questions/767372/java-string-equals-versus) — Matt Ball, May 10 '12 at 18:10

score 8 · Accepted Answer · answered May 10 '12 at 18:08

8

Use String#equals(), not ==, to compare strings.

answered May 10 '12 at 18:08

Matt Ball

354,903
100
647
710

score 0 · Answer 2 · answered May 10 '12 at 18:09

if (input != null)
                {
                    input = input.trim();
                    if (input.equals("bye"))
                        out.println("nice");

                    out.println(input);
                }

The equals() compares the content of string.

score 0 · Answer 3 · answered May 10 '12 at 18:10

You want your inner if to say this:

if (input.equals("bye"))

instead of

if (input == "bye")

The == is actually comparing the reference object (sort of like a pointer) and may sometimes work when the string is interned, but that's another topic. Use .equals()!

java can't compare strings

3 Answers3

Linked

Related