I know what -if- -else- does, but what if there is a -if- but not the -else-?

For example:
if exp {
command (A1)
command (A2)
...
}
command (B1)
command (B2)
...

How is it executed? my guess is:
If exp=1, both (A1), (A2),... and (B1), (B2),... are executed;
if exp=0, then only commands (B1), (B2),... are executed;

I sort of know this is the case, but cannot find any official document to confirm.
For example, the official help file does not specify it about this particular case:
https://www.stata.com/manuals13/pif.pdf