Question 1

How do I convert decimal to hexadecimal?

Accepted Answer

To convert decimal to hex, repeatedly divide by 16 and record remainders. Remainders 10-15 map to A-F. Example: 255 ÷ 16 = 15 R 15 → F, 15 ÷ 16 = 0 R 15 → F. Result: 255 (decimal) = FF (hex) = 11111111 (binary). Our programmer calculator converts instantly between all number bases.

Question 2

What are bitwise operations and how do they work?

Accepted Answer

Bitwise operations work on individual bits: AND (&) outputs 1 only when both bits are 1. OR (|) outputs 1 when either bit is 1. XOR (^) outputs 1 when bits differ. NOT (~) flips all bits (one's complement). Left shift (<>n) divides by 2^n (integer division). Example: 5 & 3 = 101 & 011 = 001 = 1.

Question 3

What is two's complement and why is it used?

Accepted Answer

Two's complement represents signed integers in binary. To negate: invert all bits (one's complement) then add 1. Example: +5 = 00000101, -5 = 11111010 + 1 = 11111011. This allows addition/subtraction to work identically for signed and unsigned numbers. Range for n-bit: -2^(n-1) to +2^(n-1)-1.

Question 4

How does the AND operator work in programming?

Accepted Answer

The AND operator (&) compares each bit: 1 & 1 = 1, 1 & 0 = 0, 0 & 0 = 0. Common uses: 1) Masking bits (x & 0xFF extracts lowest byte), 2) Testing if a bit is set (x & (1<<n) != 0), 3) Clearing specific bits (x & ~(1<<n)). Example: 0b1010 & 0b1100 = 0b1000 = 8.

Question 5

How do I convert ASCII to decimal or hex?

Accepted Answer

ASCII (American Standard Code for Information Interchange) maps characters to numbers 0-127. Examples: Space=32, A=65, a=97, 0=48. To convert: 'A' → decimal 65 → hex 0x41 → binary 01000001. Extended ASCII (128-255) includes Latin characters. Unicode extends this to 1.1 million+ code points.

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