1.4.1 Data Types: Character Sets

Which of the following character sets is a widely-used standard for representing text in computers and communication devices?

• ASCII

• Unicode

• Binary

• Hexadecimal

Answer explanation

Unicode is a widely-used character set that provides a unique numerical value for every character used in various writing systems. It is designed to support multiple languages and is used as a standard for representing text in computers and communication devices.

ASCII is an acronym for:

• American Standard Code for Information Interchange

• Advanced Symbolic Code for International Information

• All Standard Characters for International Integration

• Automated System for Character Interpretation and Integration

Answer explanation

ASCII stands for the American Standard Code for Information Interchange. It is a character encoding standard that represents text in computers and other devices. ASCII uses 7 bits to represent characters, allowing a total of 128 different characters.

What is the main limitation of ASCII when it comes to representing text?

• It cannot represent characters from non-Latin scripts.

• It requires a larger number of bits for character representation.

• It does not support lowercase letters.

• It is not compatible with modern computer systems.

Answer explanation

One of the main limitations of ASCII is that it only represents a limited set of characters, primarily those used in the English language. ASCII cannot represent characters from non-Latin scripts, such as Chinese, Arabic, or Devanagari.

How many bits are used to represent characters in Unicode?

• 4

• 8

• 16

• 32

Answer explanation

Unicode uses 16 bits to represent characters, allowing a much larger number of unique characters to be represented compared to ASCII. However, with the introduction of Unicode 3.1, some characters are now represented using 32 bits.

Which of the following is an advantage of Unicode over ASCII?

• Smaller file sizes for text documents.

• Support for a wider range of languages and scripts.

• Improved compatibility with legacy systems.

• Faster processing speed for character encoding.

Answer explanation

Unicode offers a significant advantage over ASCII by providing support for a much wider range of languages and scripts. It allows the representation of characters from various writing systems, making it a more inclusive and comprehensive character set compared to ASCII.

Match the following terms with their corresponding descriptions:

• Encoding

• The process of converting characters into numeric codes

• 1. UNICODE

• Represents characters using numeric codes

• Character set

• A universal character encoding standard

• Decoding

• A collection of characters with corresponding numeric values

• 1. ASCII

• The process of converting numeric codes into characters

Decode the following word, encoded using the ASCII character set. All characters are lowercase.

101 110 99 111 100 101

Decode the following word, encoded using the ASCII character set. All characters are lowercase.

97 108 103 111 114 105 116 104 109

Decode the following word, encoded using the ASCII character set. All characters are lowercase.

104 101 120 105 100 101 99 105 109 97 108

• The ​ (a)   character set is an 8-bit character set, meaning each unique character in a file is represented by ​ sets of 1s and 0s (or 1 byte).

• The ​ (b)   character set is a 8, 16 or 32-bit character set depending on which ​you use, meaning each ​character is represented by either 8, 16 or 32 sets of 1s and 0s (or 1–4 bytes).

• So, although their contents may look ​identical, a text file stored using ​ (c)   can take up more space than a file stored in ​ (d)   .

• ASCII
• UNICODE