for ($scalar) {...}
for (funcReturningScalar()) {..}
for ($hash{of}{some}{arbitrar}{size}{returning}{scalar}) {...}
for($$hash{returning}{refToScalar}) { ... }
# Many more

##</code><code>##

for ($scalar) {
    # do stuff;
}

##</code><code>##

given ($scalar) {
    when <<always>> {
        # do stuff;
    }
}

##</code><code>##

given ($scalar) {
    default {
        # do stuff;
    }
}