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Frequently Asked Questions
Why do programmers use hexadecimal?
Hex is compact — one hex digit represents exactly 4 binary bits, so 2 hex digits represent one byte (8 bits). Memory addresses, color codes (#FF5733), and byte values are all naturally expressed in hex. It bridges the gap between binary (machine-level) and decimal (human-readable).
What is binary and why does it matter?
Binary (base 2) is the language of computers — every bit is either 0 or 1, representing off or on states in transistors. Understanding binary helps with bitwise operations, network subnetting, file permissions (chmod 755 = 111 101 101 in binary), and low-level programming.
How do I convert hex to decimal in my head?
Multiply each digit by its positional power of 16. Example: 0xFF = (15×16) + 15 = 240 + 15 = 255. Or: the last digit is its value, each position left multiplies by 16. Common values to memorise: 0x0A=10, 0x10=16, 0x64=100, 0xFF=255.
What is octal (base 8)?
Octal uses digits 0–7. Each octal digit represents 3 binary bits. Octal is used in Unix/Linux file permissions — chmod 755 means owner:rwx (7=111), group:r-x (5=101), others:r-x (5=101). Less common than hex but still encountered in embedded systems.