1.
2.
A= 1 ;
B=null;
IF((true)or(A=B))then...
В этом случае выполниться то, что в ветке else или ничего, ибо сказано в писании:
LangRefSyntax IF ( <condition>)
THEN < compound_statement>
[ELSE < compound_statement>]
Description The IF … THEN … ELSE statement selects alternative courses of action by testing a
specified condition.
condition is an expression that must evaluate to TRUE to execute the statement or block
following THEN. The optional ELSE clause specifies an alternative statement or block
executed if condition is not TRUE.
Argument Description
condition Boolean expression that evaluates to TRUE, FALSE, or UNKNOWN; must
be enclosed in parentheses
THEN compound_statement Statement or block executed if condition is TRUE
ELSE compound_statement Optional statement or block executed if condition is not TRUE
