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- Representing characters: ASCII
Representing characters: ASCII
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Every letter, digit and symbol you type is stored as a binary code. ASCII is the classic character set.
Character sets
A character set gives every character a unique binary code.
7-bit ASCII has 27 = 128 codes, covering English letters, digits, punctuation and control codes such as Enter.
7-bit ASCII has 27 = 128 codes, covering English letters, digits, punctuation and control codes such as Enter.
Codes run in order
Unicode (International GCSE)
ASCII cannot store characters from most of the world's languages or emoji.
Unicode uses more bits per character, so it can represent many thousands of characters, and its first 128 codes match ASCII.
The cost is that text can take more storage.
Unicode uses more bits per character, so it can represent many thousands of characters, and its first 128 codes match ASCII.
The cost is that text can take more storage.
'A' is 65. What is the ASCII code for 'G'?
- G is 6 letters after A.
- 65 + 6
Answer: 71
7-bit ASCII gives 128 characters, with letters and digits in order. 'A' = 65, 'a' = 97, '0' = 48. Unicode extends this to many more characters.
The interactive lesson includes the diagrams for this topic.
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