Set 21: Passing by Reference and by Value

Primitive data types are the most basic data types available within the Java language. There are 8: boolean, byte, char, short, int, long, float, and double . These types serve as the building blocks of data manipulation in Java. Such types serve only one purpose — containing pure, simple values of a kind.

We have already explored and used int, double, Boolean, and char data types. Below are a few more,

• long: an integer which gives more digits than an int
• short: an integer which gives fewer digits than an int
• float: a floating point number (a double is also a floating point number) that gives fewer significant figures than an double

Primitive data types always store a value

Reference data types are objects and do not store values, but instead point to a reference (or location) in the memory. Objects include arrays and Strings; they also include classes.

The video below provides further explanation,

The above example illustrates how different data types are handled in memory. When passing different data types to a method in a program, you should be mindful of how they are stored in the memory to avoid unexpected results.

The below example is illustrative,