Exam Tips - Character Sets

Exam Tips - Character Sets

Most common exam questions:

• "What is ASCII?" → Character set with 128 characters (7-bit), covers English alphabet, numbers, punctuation
• "Why use Unicode?" → Covers ALL languages and symbols (143,000+ characters), international support, emoji
• "ASCII code for 'A'?" → 65 (memorize this!)
• "Difference UTF-8 vs UTF-16?" → UTF-8 uses 1-4 bytes (efficient for English), UTF-16 uses 2-4 bytes (efficient for Asian languages)
• "How many bytes for ASCII character?" → 1 byte

Key facts to memorize:

• ASCII: 7-bit (128 characters), English only, 1 byte per character
• Extended ASCII: 8-bit (256 characters), accented letters
• Unicode: 143,859 characters, all languages, UTF-8/16/32 encodings
• UTF-8: 1-4 bytes, most common, web standard
• Common codes: 'A'=65, 'a'=97, '0'=48, space=32

Common mistakes to avoid:

• Confusing character set (Unicode) with encoding (UTF-8) - they're related but different!
• Saying ASCII is 8-bit - NO! Standard ASCII is 7-bit (128 characters)
• Thinking Unicode uses more space - depends on encoding! UTF-8 is same as ASCII for English
• Mixing up 'A' (65) and 'a' (97) - uppercase ≠ lowercase