ASCII, Unicode, and UTF-8 Basics

Questions and Answers

To create emojis

To map binary code into characters (correct)

To compress data

To support multiple languages

256

512

128 (correct)

A hexadecimal number representing a character (correct)

A binary representation of a character

A unique byte sequence

A Unicode character itself

It is a variable-length encoding Signup and view all the answers

To support more languages than just English Signup and view all the answers

UTF-8 is backwards compatible with ASCII Signup and view all the answers

4 Signup and view all the answers

Because it is widely supported and efficient Signup and view all the answers

It only supports English characters Signup and view all the answers

U+0065 Signup and view all the answers

Study Notes

Maps bits (zeros and ones) into characters, necessary because computers store data as zeros and ones
Uses 7 bits for encoding, allowing for 2^7 (128) different characters to be represented
Example: 65 represents 'A', 116 represents 'T', and case matters
Original 7 bits were only enough to represent English characters, punctuation, and some codes
Drawbacks: limited character representation, competition for additional characters with the 8th bit

A universal character encoding that supports many different alphabets and even emojis
Specifies which character refers to which code point (hexadecimal number), but doesn't define how mapping should be implemented
Code point example: U+0001 represents 'a' and is equal to 65 in decimal

Stands for Unicode Transformation Format, an algorithmic mapping from every Unicode code point to a unique byte sequence
Variable length encoding, meaning characters with small code point values can be represented with one byte, and those with large values can be represented with up to four bytes
Backwards compatible with ASCII, meaning any ASCII file can also be read with UTF-8
Most dominant encoding for the World Wide Web, accounting for roughly 98% of all web pages