Why are Cobol and Fortran are case sensitive?

Answer 1

The languages are not case sensitive in most implementations. However, Fortran versions from F77 forward allow the use of lower-case letters in statements; the compiler simply translates them all to upper-case before processing.

Case sensitivity is a contentious item among programmers. Typing in mixed, INsensitive case is a lot more readable, but programming with case sensitivity can be a recipe for disaster. For example, it's a lot easier to read a name called SetOutputStage than SETOUTPUTSTAGE or setoutputstage. But if the compiler is case sensitive, all it takes is one fumblefingered letter to create 2 variables - e.g. SetOutputStage and SetOutputstage, which are virtually indistinguishable to the eye!

Answer 2

The real-world is case-sensitive and it would actually take more effort to remove case-sensitivity. Keyboards treat the characters 'A' and 'a' as being separate entities with different character codes, it's only humans that treat them as being different cases of the same letter. In order for a computer to treat them as being the same letter, it must convert all characters to the same case (whether upper or lower case) and that alone takes far more effort than simply treating them as being the completely separate characters they actually are. C is a high-performance language, so it makes no sense to waste time converting characters unnecessarily.

Answer 3

The case-sensitivity (or lack thereof) of any programming language typically stems from the systems upon which the language was originally intended, or from the languages upon which they were derived. C has its roots in UNIX which is an inherently case-sensitive system. That is, README.TXT and readme.txt are distinct file identifiers that may co-exist within the same folder. It only makes sense for C to treat identifiers in exactly the same way. After all, the fewer inconsistencies we introduce into a system, the easier that system is to use.

You might ask why UNIX is case-sensitive, but the answer is simple. While the Latin alphabet has 26 distinct characters with two representations each (uppercase and lowercase), implementing a case-insensitive system in English is trivial. However, most people prefer to use identifiers in their own native language but not all languages lend themselves to a case-insensitive system quite so readily. For instance, the German eszett "ß" has no uppercase equivalent while certain Arabic scripts have certain letters with three representations rather than two. Case-sensitivity caters for all languages equally.

Answer 4

Cobol is not a case sensitive language. It does not matter if a variable or command is upper or lower case or a mixture of upper and lower case letters. They are all treated the same.