Data Types in Java

Source: Dev.to

Data types specify the different sizes and values that can be stored in a variable. Java is a statically‑typed language, so every variable must be declared with its type before it is used.

Primitive Data Types

• byte – 8‑bit signed integer. Range: -128 to 127.
• short – 16‑bit signed integer. Range: -32,768 to 32,767.
• int – 32‑bit signed integer. Range: -2,147,483,648 to 2,147,483,647.
• long – 64‑bit signed integer. Range: -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807.
• float – 32‑bit single‑precision floating‑point number.
• double – 64‑bit double‑precision floating‑point number.
• boolean – Represents true or false.
• char – 16‑bit Unicode character.

int a = 10;
float f = 3.14f;
boolean flag = true;
char letter = 'A';

Non‑Primitive (Reference) Data Types

• Classes – Templates for creating objects.
• Interfaces – Contracts that define methods for classes.
• Arrays – Collections of elements of the same data type.
• String – Represents a sequence of characters.

String name = "aaa";
int[] numbers = {1, 2, 3, 4};

Primitive vs Non‑Primitive Data Types

Both categories are essential: primitives provide efficient, low‑level data handling, while non‑primitives enable more complex structures and behavior.