Java Reference
In-Depth Information
Using the
+
Sign with Strings
If you connect two strings with the + operator, the result is the concatenation (pasting) of
the two strings.
EXAMPLE
String name = "Chiana";
String farewell = "Good bye " + name;
System.out.println(farewell);
This sets
farewell
to the string
"Good bye Chiana"
. So, it outputs the following to the
screen:
Good bye Chiana
Note that we added a space at the end of
"Good bye "
.
a string when you connect it to a string with the
+
operator. For numbers, it does the
obvious thing. For example,
String solution = "The answer is " + 42;
will set the
String
variable
solution
to
"The answer is 42"
. Java converts the
integer constant
42
to the string
"42"
and then concatenates the two strings
"The
answer is "
and
"42"
to obtain the longer string
"The answer is 42"
.
Notice that a number or other value is converted to a string object only when it is
connected to a string with a plus sign. If it is connected to another number with a plus
sign, it is not converted to a string. For example,
System.out.println("100" + 42);
outputs
10042
but
System.out.println(100 + 42);
outputs
142
Classes
Classes
are central to Java and you will soon be defining and using your own classes.
The class
String
gives us an opportunity to introduce some of the notation and
