Why Do C and C Still Use Digraphs?

The Enigmatic Digraphs of C and C

Despite their modern dominance, early programming environments often lacked support for the complete ISO 646 character set. Compounding this limitation, many programmers relied on keyboards that were incompatible with the standard. To alleviate these challenges, the ingenious solution of digraphs emerged.

Digraphs are sequences of two characters that represent a single character from the ISO 646 character set. While seemingly cumbersome today, this innovative notation allowed programmers to circumvent the constraints imposed by their hardware and software limitations.

In the example provided, the digraphs are utilized within a macro definition to define a buffer size. These special character sequences enable the unambiguous representation of characters like the curly brace "{", which might otherwise be unavailable or misinterpreted due to keyboard or compiler compatibility issues.

Thus, the existence of digraphs in C99 and C can be attributed to the historical necessity to bridge the gap between the limitations of early programming environments and the demands of the ISO 646 character set.

The above is the detailed content of Why Do C and C Still Use Digraphs?. For more information, please follow other related articles on the PHP Chinese website!