What every developer should know about Text Encoding

As a software engineer, understanding text encoding is a crucial skill. In today’s digital age, we interact with a vast amount of text data daily, and knowing how it is encoded is essential to ensure that the data is correctly interpreted by different systems and applications. In this blog, we will explore the fundamentals of text encoding and why software engineers need to know about it.

Text Encoding — What is it?

In simple terms, text encoding is the process of converting human-readable characters into a machine-readable format. When we create a text file, we enter the text using our keyboard, and it gets stored in the file system. However, the computer cannot understand the text in the way humans do. To be able to process and store the text data in a machine-readable format, it needs to be encoded.

Text encoding involves assigning a numerical value to each character in the text. These numerical values are then converted into binary code, which can be stored and processed by the computer. Different text encoding standards exist, each with its own set of numerical values and binary codes.

The Evolution of Text Encoding

The earliest text encoding standards used a single byte (eight bits) to represent each character. These standards were sufficient to encode the characters used in the English language but could not accommodate characters from other languages. As a result, many different text encoding standards emerged, each with its own set of characters.

One of the most popular text encoding standards is ASCII (American Standard Code for Information Interchange). ASCII uses a single byte to represent each character and can encode 128 different characters, including letters, numbers, punctuation, and control characters. It only uses 7 bits to represent the character and the last bit is always 0.

However, as computers became more prevalent and people started communicating globally, it became clear that ASCII was not sufficient. There was not enough binary representations available to represent all the characters from different languages in ASCII since it only uses 7 bits.

You might think that if 1 byte is insufficient. Why not use more than that like 4 bytes and represent any character?
The issue with this approach is that it will take more space to represent small characters too. So it will be very memory inefficient.

In the 1980s, a new standard called Unicode was developed to address this issue. It uses something known as code points to represent any character or even emojis.

Code Points

Code points are just a mapping of some numbers to the characters. These numbers are called code points. For example, code point 49 is mapped to the literal value 1. Similarly, code point 65 is mapped to the character ‘A’. So Unicode is not an encoding scheme rather, it is an information technology standard for encoding, representation and text handling.

+-------------+-------+
| Code Point  | Value |
+-------------+-------+
|     38      |  &    |
|     49      |  1    |
|     65      |  A    |
|     66      |  B    |
|     67      |  C    |
|     ...     |       |
+-------------+-------+

There are other different ways to encode these Unicode code points to bits. Let us see some of these text encoding schemes.

Types of Text Encoding

There are several different types of text encodings, including UTF-8, UTF-16, and others. The most widely used encoding is UTF-8, which is a variable-length encoding scheme that is backwards compatible with ASCII. This means that UTF-8 can represent all ASCII characters using one byte, but it can also represent non-ASCII characters using multiple bytes. It can have a maximum of 4 bytes. So, UTF-8 solves all the problems of other schemes in a memory efficient manner as it is a variable-length encoding scheme. That is why it has become the default encoding for many systems.

UTF-16 is another encoding scheme that uses either two or four bytes to represent characters, but it is less commonly used than UTF-8. Other encoding schemes include ISO-8859 and Windows-1252, which are still used in legacy systems and applications.

Text Encoding Issues

Text encoding issues can cause errors and unexpected behaviour in software. For example, if a program expects the text to be encoded using UTF-8 but receives text encoded using a different encoding scheme, the program may not be able to correctly interpret the text.
Programming Language Support

Many programming languages and frameworks provide built-in support for text encoding. For example, in Java, the String class supports Unicode encoding by default, and the InputStreamReader and OutputStreamWriter classes can be used to read and write text in different encoding schemes.
Conclusion

In conclusion, text encoding is a crucial concept in software engineering that enables characters to be represented electronically. Understanding text encoding is essential for developing software that can handle characters from different writing systems and languages.