Question 1

"What is hexadecimal?"

Accepted Answer

"Hexadecimal (base 16) uses digits 0–9 and A–F. It is often used in computing (e.g. for colors or memory addresses)."

Question 2

"What is octal?"

Accepted Answer

"Octal (base 8) uses digits 0–7. It is less common today but still used in some computing contexts."

Question 3

"Can I convert negative numbers?"

Accepted Answer

"This tool accepts only non-negative integers. For negative or fractional values you would need a different approach."

Question 4

"Why do computers use binary?"

Accepted Answer

"Binary (base 2) maps directly to the two physical states of electronic circuits: off (0) and on (1). All data a computer processes — numbers, text, images — is ultimately stored and manipulated as sequences of 0s and 1s."

Question 5

"Where is hexadecimal used in web development?"

Accepted Answer

"Hex is used for CSS colors (#ff5733), HTML character references, HTTP encoding, and crypto hashes. A six-digit hex color is three pairs: RR GG BB in base 16."

Question 6

"How do I add two binary numbers?"

Accepted Answer

"Add column by column from right to left, carrying when the sum exceeds 1. Example: 0101 + 0011 = 1000 (5 + 3 = 8). Convert both to decimal first if you only need the result."

Question 7

"What is the largest value that fits in one byte?"

Accepted Answer

"A byte is 8 binary digits, so the maximum unsigned value is 11111111 in binary = FF in hex = 255 in decimal."

Question 8

"Why do programmers count from 0?"

Accepted Answer

"Arrays in most languages are zero-indexed because memory addresses start at offset 0. Binary naturally represents 0 to (2ⁿ − 1) for n-bit values, making zero-based counting efficient."

Question 9

"What is the difference between hex and base-64?"

Accepted Answer

"Hex uses 16 symbols (0–9 A–F), encoding each byte as two characters. Base-64 uses 64 symbols (A–Z a–z 0–9 +/), encoding every 3 bytes as 4 characters — more compact but not the same as a number base."

Question 10

"How do I read a hex color code like #3a9fbf?"

Accepted Answer

"Split it into three byte pairs: 3A (red) = 58 decimal, 9F (green) = 159 decimal, BF (blue) = 191 decimal. That gives rgb(58, 159, 191), a medium cyan-blue."

Question 11

"What are signed vs unsigned integers?"

Accepted Answer

"Unsigned integers use all bits for magnitude (0 to 2ⁿ−1). Signed integers reserve the top bit for sign, giving a range of −2ⁿ⁻¹ to 2ⁿ⁻¹−1. For example, an unsigned 8-bit integer goes 0–255, while signed 8-bit goes −128–127."

Question 12

"How are IP addresses related to hex?"

Accepted Answer

"IPv4 addresses like 192.168.1.1 can be written as hex: C0.A8.01.01. IPv6 addresses are always written in hex groups (e.g. 2001:0db8:85a3::1). Converting to decimal or hex is a common networking task."

Question 13

"What does 0x mean before a number?"

Accepted Answer

"The 0x prefix is a convention in C, Python, JavaScript, and many languages to denote a hexadecimal literal. For example, 0xFF equals 255 in decimal."

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