How is the string class defined in Java?

In Java, you can define the String class using the following way:

1. Direct assignment: You can use double quotes to enclose the string content and directly assign it to a String variable. For example:

String str = "Hello World";

1. By utilizing constructor methods, it is possible to create a String object using the String class constructor. For example:

String str = new String("Hello World");

It is important to note that both of the above methods will create a new String object. Also, the String class is immutable, once a String object is created, its content cannot be changed. If modifications to a string are needed, the StringBuilder class or StringBuffer class can be used.