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Learn Java: Manipulating Variables
String Concatenation

We have covered a lot of built-in functionality in Java throughout this lesson. We’ve seen +, -, <, ==, and many other operators. Most of these only work on primitives, but some work on Strings too!

Let’s say we want to print out a variable, and we want to describe it as we print it out. For our bank account example, imagine we want to tell the user:

Your username is: <username>

With the value of the variable username displayed.

The + operator, which we used for adding numbers together, can be used to concatenate Strings. In other words, we can use it to join two Strings together!

String username = "PrinceNelson"; System.out.println("Your username is: " + username);

This code will print:

Your username is: PrinceNelson

We can even use a primitive datatype as the second variable to concatenate, and Java will intelligently make it a String first:

int balance = 10000; String message = "Your balance is: " + balance; System.out.println(message);

This code will print:

Your balance is: 10000



In our zoo, we have a certain number of animals, stored in animals, of a certain species, stored in species.

Use + to make a new String variable called zooDescription. It should hold a String that looks like:

Our zoo has <animals> <species>s!

For example, if we had 5 animals that were all of the species Masai Giraffe, the String would say:

Our zoo has 5 Masai Giraffes!

Print out the variable zooDescription!

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