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4.5. String Operators - Concatenation

Strings can be appended to each other which creates a new string using the + operator . This is also called concatenation.

public class Test1 { public static void main(String[] args) { String start = "Happy Birthday"; String name = "Jose"; String result = start + " " + name; System.out.println(result); } }

Note

Note that spaces are not added between strings automatically. If you want a space between two strings then add one.

You can even add other items to a string using the + operator. The other item will be converted to a string using the toString operator if it is an object and then appended to the current string. All objects inherit a toString method that returns a string representation of the object.

What do you think the following will print?

public class Test2 { public static void main(String[] args) { String message = "12" + 4 + 3; System.out.println(message); } }

Note

If you are appending a number to a string it will be converted to a string first before being appended.

Since the same operators are processed from left to right this will print 1243. First 4 will be turned into a string and appended to 12 and then 3 will be turned into a string and appended to 124. If you want the addition to take place before the numbers are turned into a string what should you do? Try to modify the code above so that it adds 4 + 3 before appending the value to the string.

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