On String Equality (using ==)

Question

Hello. I am trying to create a program that will merge sentences on their first similar word occurence, i.e.:
Given "good day. i would like to see you at the office"
and "how are you feeling today?"
It will produce "good day. i would like to see you feeling today".
If there are no similar words, the program will just concatenate the Strings.
I tested the examples above and I got "good day. i would like to see you at the office how are you feeling today". Obviously, something's wrong.
So I fiddled around my code putting printlns here and there. Then I found out that my comparison loops doesn't stop. Equality ( == ) always evaluates to false.
On my tester class, I tried the following:
String intro = "good day. i would like to see you at the office";
String outtro = "how are you feeling today?";
String[] fooArray = intro.split(" ");
String[] barArray = intro.split(" ");
String foo = fooArray[7];
String bar = barArray[2];
System.out.println("Is foo equal to bar? " + foo == bar);The abovementioned code returned false.
Then I tried the following
String intro = "good day. i would like to see you at the office";
String outtro = "how are you feeling today?";
String[] fooArray = intro.split(" ");
String[] barArray = intro.split(" ");
String foo = fooArray[7];
String bar = barArray[2];
System.out.println("How about chars? " + foo.charAt(0) == bar.charAt(0));This time around, it returned true.
So I'm guessing that maybe I should just create a function that will loop through the chars of the String and compare them.
However, I am bothered by how Java handled foo == bar . Can someone explain to me why this happened? Is there a workaround to this one or should I always create a function that loops through chars everytime I want to compare Strings?
Thanks!

Answer 1

== compares references for equality. When you want to compare two Object instances for equality you use the equals method. This applies not only to String but any other type of Object..