Arematics Java Beginner - Primitive Data Types

The third video of the Arematics Java Beginner Course teaching Java basics such as Object Orientation, Java Core API, Spring and Web Development.

Description:

In this part we talk about the primitive data types. These are foundational to Java programming, and understanding them is crucial.

Bits and Bytes

Before diving into Java, let's refresh our understanding of bits and bytes. A byte consists of eight bits, each of which can have a value of either 0 or 1. This binary system allows us to represent numbers ranging from 0 to 255. However, to accommodate both positive and negative values, most programming languages, including Java, use the two's complement system. In this system, the first bit indicates the sign: 0 for positive and 1 for negative. This adjustment shifts our range from 0-255 to -128 to 127.

Examples:
Changing the third bit from the left gives us the decimal number 4.
Modifying the sixth bit results in the decimal number 36.
Switching the first bit gives us the decimal -92.
Changing both the first and second bits results in the decimal -28.
Java's Primitive Data Types

Java offers a variety of primitive data types:

byte: 8 bits
short: 16 bits
int and float: 32 bits each
long and double: 64 bits each

While int and long can only store whole numbers, float and double can store floating-point numbers. However, due to their logarithmic calculations, floating-point numbers might have slight precision losses.

Other Data Types:

The boolean data type can have values of either 0 (false) or 1 (true). The char data type, with its 16 bits, is used to represent characters and can thus be employed to depict text in applications.

Working with Primitive Data Types in Java

Let's explore some practical examples:

Declare a byte with a value of 127. If we try to increment this value, Java will flag an error due to overflow.
Declare a short and assign a byte to it. This is feasible because a short has a larger range than a byte.
Similarly, an int can hold a short, and a long can hold an int.
Floating Types:

When working with floating types like double and float, it's essential to note the precision. For instance, dividing values might yield different results based on whether you're using a float or a double due to their precision differences.