Which statement about Unicode relative to ASCII is true?

Which statement about Unicode relative to ASCII is true?

• A. ASCII uses 7-bit encoding for 128 characters.
• B. Unicode assigns code points to characters and is encoded in UTF-8/UTF-16/UTF-32.
• C. Unicode uses a fixed 8-bit encoding.
• D. Unicode cannot represent emoji.

Answer: (B)

Unicode assigns code points to characters and is encoded in UTF-8/UTF-16/UTF-32. This means each character has a unique number in the Unicode set, and there are multiple ways to turn those numbers into bytes depending on the encoding you choose. ASCII is a 7-bit system for 128 characters, and those first 128 Unicode code points are the same ones ASCII uses, so plain ASCII text is valid Unicode text. Unicode isn’t fixed-width; encodings vary in length—UTF-8 uses 1 to 4 bytes, UTF-16 uses 2 or 4 bytes, and UTF-32 uses 4 bytes. The statement that Unicode uses a fixed 8-bit encoding isn’t correct. Plus, Unicode can represent emoji, since emoji are assigned their own code points within Unicode. This shows how Unicode extends ASCII to cover a vast range of characters and symbols while remaining backward compatible for the first 128 characters.

Unicode assigns code points to characters and is encoded in UTF-8/UTF-16/UTF-32. This means each character has a unique number in the Unicode set, and there are multiple ways to turn those numbers into bytes depending on the encoding you choose. ASCII is a 7-bit system for 128 characters, and those first 128 Unicode code points are the same ones ASCII uses, so plain ASCII text is valid Unicode text. Unicode isn’t fixed-width; encodings vary in length—UTF-8 uses 1 to 4 bytes, UTF-16 uses 2 or 4 bytes, and UTF-32 uses 4 bytes. The statement that Unicode uses a fixed 8-bit encoding isn’t correct. Plus, Unicode can represent emoji, since emoji are assigned their own code points within Unicode. This shows how Unicode extends ASCII to cover a vast range of characters and symbols while remaining backward compatible for the first 128 characters.