Number Systems for Programming and Data
While humans use the Decimal system, computers operate on Binary, and programmers often use Hexadecimal for better readability.
1. Key Number Bases
- Decimal (Base 10): 0–9 (Human standard)
- Binary (Base 2): 0, 1 (Computer hardware standard)
- Hexadecimal (Base 16): 0–9 and A(10)–F(15). Four binary bits can be represented by a single hex digit, making data much easier to read.
2. Web Colors: RGB Hex Codes
The 6-digit hex code (#RRGGBB) used in HTML/CSS represents the intensity of Red, Green, and Blue from 00 to FF (255 in decimal).
- #FF0000: Max Red → Red
- #00FF00: Max Green → Green
- #0000FF: Max Blue → Blue
- #FFFFFF: Combination of all → White
- #000000: Absence of light → Black
3. Conversion Rules
Hex → Decimal
Multiply each digit by the power of 16 and sum them up.
- Example:
0x1A= 1 × 16¹ + 10 × 16⁰ = 26
Binary → Hex
Group bits into fours from the right and convert each set.
- Example:
1010 1111(binary) =AF(hex)
4. Programming Conventions
- 0x Prefix: Used in C, C++, Java, JS, and Python to denote hexadecimal numbers.
- # Prefix: Used in web standards to denote color codes.