Datatypes

• Primitive Data Type: boolean, short, char, int, byte, float, long, and double.
• Non-Primitive Data Type or Object Data Type: String, Array, etc.

Reference Types

package com.example;

import java.util.Date;

public class ReferenceTypes {
  public static void main(String... args) {
    String name = new String("MyName");
    Date date = new Date();

    System.out.println("String : "+name);
    System.out.println("Date : "+date);
  }
}

/*
Output
=======
$ java com/example/ReferenceTypes.java
String : MyName
Date : Sat Apr 19 13:09:27 IST 2025
*/

Primitive Types

package com.example;

public class PrimitiveTypes {
  public static void main(String... args) {
    byte byteVar = 127;
    short shortVar = 32000;
    int intVar = 999;
    long longVar = 1_000_000L; // Use this convention for better readbility
    float floatVar = 0.0F;
    double doubleVar = 0.098769;
    char charVar = 'a';
    boolean boolVar = false;

    System.out.println("Byte: "  +byteVar);
    System.out.println("Short: " +shortVar);
    System.out.println("Int: "   +intVar);
    System.out.println("Long: "  +longVar);
    System.out.println("Float: " +floatVar);
    System.out.println("Double: "+doubleVar);
    System.out.println("Char: "  +charVar);
    System.out.println("Bool: "  +boolVar);
  }
}

/*
Output
===========
$ java com/example/PrimitiveTypes.java
Byte: 127
Short: 32000
Int: 999
Long: 1000000
Float: 0.0
Double: 0.098769
Char: a
Bool: false
*/

References:

• Types of References - Link
• Oreilly Reference doc - Link
• Primitive Types, Oracle
• Java Primitives Types