This guide explains how Java primitive data types are stored in memory using simple examples, binary formats, and visual aids.
🔹 1. byte a = 10;
byte a = 10; Variable Type Size Decimal Binary a byte 1 B 10 00001010
Visual: +--------+ |00001010| +--------+
🔹 2. short b = 300; short b = 300; Variable Type Size Decimal Binary b short 2 B 300 00000001 00101100
Visual: +--------+--------+ |00000001|00101100| +--------+--------+
🔹 3. int c = 1000;
int c = 1000; Variable Type Size Decimal Binary c int 4 B 1000 00000000 00000000 00000011 11101000
Visual: +--------+--------+--------+--------+ |00000000|00000000|00000011|11101000| +--------+--------+--------+--------+
🔹 4. long d = 100000L; long d = 100000L; Variable Type Size Decimal Binary (simplified) d long 8 B 100000 Ends with 00011000011010100000
Visual (simplified): +--------+--------+...+--------+ |00000000...00011000011010100000| +--------+--------+...+--------+
🔹 5. char e = 'A'; char e = 'A'; Variable Type Size Char Unicode Binary e char 2 B 'A' 65 00000000 01000001
Visual: +--------+--------+ |00000000|01000001| +--------+--------+
🔹 6. float f = 3.14f; float f = 3.14f; Variable Type Size Value Binary (approx) f float 4 B 3.14 01000000 01001000 11110110 11000010
Visual: +--------+--------+--------+--------+ |01000000|01001000|11110110|11000010| +--------+--------+--------+--------+
🔹 7. double g = 3.14; double g = 3.14; Variable Type Size Value Binary (approx) g double 8 B 3.14 01000000 00001001 00111111 ...
Visual: +--------+--------+--------+--------+--------+--------+--------+--------+ |01000000|00001001|00111111|11011011|00110000|00000000|00000000|00000000| +--------+--------+--------+--------+--------+--------+--------+--------+
🔹 8. boolean h = true; boolean h = true; Variable Type Size Value Binary h boolean 1 B true 00000001
Visual: +--------+ |00000001| +--------+
🧩 Summary Table
| Type | Size | Example Value | Binary Bits (approx) |
|---|---|---|---|
| byte | 1 byte | 10 | 00001010 |
| short | 2 bytes | 300 | 00000001 00101100 |
| int | 4 bytes | 1000 | 00000000 00000000 00000011 11101000 |
| long | 8 bytes | 100000 | (Long binary) |
| char | 2 bytes | 'A' | 00000000 01000001 |
| float | 4 bytes | 3.14f | 01000000 01001000 ... |
| double | 8 bytes | 3.14 | 01000000 00001001 ... |
| boolean | 1 byte | true | 00000001 |
📌 Note: Floating point binary values follow IEEE 754 format and are approximated here for simplicity.