Is there a shorter way to write compound 'if' conditions? [duplicate]

Answer 1

In this case you could use a switch:

switch (ch) {
case 'A':
case 'B':
case 'C':
    // do something
    break;
case 'D':
case 'E':
case 'F':
    // do something else
    break;
...
}

While this is slightly more verbose than using strchr, it doesn't involve any function calls. It also works for both C and C++.

Note that the alternate syntax you suggested won't work as you might expect because of the use of the comma operator:

if  ( ch == 'A', 'B', 'C', 'D', 'E', 'F' )

This first compares ch to 'A' and then discards the result. Then 'B' is evaluated and discarded, then 'C', and so forth until 'F' is evaluated. Then 'F' becomes the value of the conditional. Since any non-zero value evaluated to true in a boolean context (and 'F' is non-zero), then the above expression will always be true.