GCSE Computer Science Revision

Understanding Character Sets

A character set is a collection of characters that a computer recognizes and processes. Each character in a set is assigned a unique code. Character sets are logically ordered, making it possible to predict and calculate character codes based on their sequence.

Logical Ordering of Character Sets

Character sets are designed so that the codes are logically sequenced. For example, in ASCII, the character code for 'B' is one more than the code for 'A'. This sequential ordering facilitates easier manipulation and understanding of text data in computing.

For instance, in ASCII:

'A' has the code 65
'B' has the code 66
And so on...

Differences and Impacts of Character Sets

Different character sets have been developed to accommodate various languages and symbols. Some of the most common include ASCII, Unicode, and Extended ASCII.

ASCII: Primarily used for English. It is a 7-bit character set encoding 128 characters.
Extended ASCII: An 8-bit character set, providing additional 128 characters to the standard ASCII set.
Unicode: Designed to include characters from most of the world's writing systems, making it more comprehensive and widely used in modern computing.

The choice of character set can impact data storage, compatibility, and the ability to represent international characters.

Character Sets in Practice

Understanding character sets is crucial for tasks such as data encoding, web development, and internationalization of software applications.

Exercise:

Question: Why is Unicode preferred over ASCII in modern computing applications?

Answer: Unicode is preferred because it supports a wide range of characters from various languages and symbols, unlike ASCII which is limited to English characters.