Why do we need break after case statements?

Question

Why doesn\'t the compiler automatically put break statements after each code block in the switch? Is it for historical reasons? When would you want multiple code blocks to e

Answer 1

As far as the historical record goes, Tony Hoare invented the case statement in the 1960s, during the "structured programming" revolution. Tony's case statement supported multiple labels per case and automatic exit with no stinking break statements. The requirement for an explicit break was something that came out of the BCPL/B/C line. Dennis Ritchie writes (in ACM HOPL-II):

For example, the endcase that escapes from a BCPL switchon statement was not present in the language when we learned it in the 1960s, and so the overloading of the break keyword to escape from the B and C switch statement owes to divergent evolution rather than conscious change.

I haven't been able to find any historical writings about BCPL, but Ritchie's comment suggests that the break was more or less a historical accident. BCPL later fixed the problem, but perhaps Ritchie and Thompson were too busy inventing Unix to be bothered with such a detail :-)