Special Edition Using Java 2 Standard Edition

Comparing Strings

Often, you need to know when two strings are equal. For example, you might want to compare a string entered by the user to another string in your program or compare data returned by the database for a particular value. There are three general ways you can compare strings:

• Calling the equals() method

• Calling the equalsIgnoreCase() method

• Using the normal comparison operator ==

The equals method returns true when the argument is non-null and the argument string represents the same set of characters as the source string. Otherwise, it returns false. Here's an example:

String str = "This is a string";
boolean result = str.equals("This is a string");

Here, the boolean variable result is equal to true. Because strings of exactly ...