Strings

A string is a sequence of characters, where each character is represented by one or more numbers. In the early days of computing, each character was represented by a single byte, which could represent 128 different characters.

If you wanted to transmit some information between computer systems, you would send a sequence of bytes, where each byte has a single character.

Why 7 bits instead of 8?

ASCII was developed in the early 1960s when computing hardware was significantly constrained. Many early computers communicated via teletype machines that used 7-bit characters, and ASCII was designed to be compatible with these existing systems.

In many early computer systems, which were far less reliable than the ones we have today, the 8th bit was reserved for error detection through parity checking. In telecommunications, this extra bit helped verify if data was transmitted correctly.

For English text and basic computing needs, 128 characters was considered adequate, as this was enough to include all uppercase and lowercase letters, numbers, punctuation, and control characters.

The limitations of ASCII's 7-bit encoding eventually led to the development of extended ASCII variants and ultimately Unicode, which addresses the need to represent characters from all of the world's writing systems.

Unicode

Unicode is a universal character encoding standard that aims to represent all characters from all writing systems in a single encoding. It is a superset of ASCII, and is the most common encoding for text in the world.

Encodings

link to all string encodings