When the execution is not explicitly terminated at the end of a switch case, it continues to execute the statements of the following case. While
this is sometimes intentional, it often is a mistake which leads to unexpected behavior.
Noncompliant code example
switch ($myVariable) {
case 1:
foo();
break;
case 2: // Both 'doSomething()' and 'doSomethingElse()' will be executed. Is it on purpose ?
do_something();
default:
do_something_else();
break;
}
Compliant solution
switch ($myVariable) {
case 1:
foo();
break;
case 2:
do_something();
break;
default:
do_something_else();
break;
}
Exceptions
This rule is relaxed in following cases:
switch ($myVariable) {
case 0: // Empty case used to specify the same behavior for a group of cases.
case 1:
do_something();
break;
case 2: // Use of continue statement
continue;
case 3: // Case includes a jump statement (exit, return, break &etc)
exit(0);
case 4:
echo 'Second case, which falls through';
// no break <- comment is used when fall-through is intentional in a non-empty case body
default: // For the last case, use of break statement is optional
doSomethingElse();
}
