Java 11 and 12 – New Features

Example of syntax and semantics

Let's redefine the Emp class, which we used at the beginning of the chapter, as a data class:

record Emp(String name, int age) { }      // data class - one liner                                           // code 

The preceding code uses the record keyword to define a data class, accepting a comma-separated variable name and type, required to store the state. The compiler automatically generates default implements for the object methods (equals(), hashCode(), and toString()) for data classes.

The code looks clear and compact. A reader would immediately know the intent of this single line of code—a carrier of the data name (type String) and age (type int). Another advantage for a reader is that they wouldn't have to read through constructors, accessors, ...