If() conditional statements and queries may use more than one argument using logical joins. See AND and OR join syntax.
( A & B )
Reads: if condition A AND condition B are true, then this compound query is true.
Contrast this with the &= operator (below).
( A &= B )
Reads: result is true if condition A is currently true and, if so, if condition B is also true.
Thus, if condition A is false, condition B is not checked and the overall result is false. Thus in some cases only condition A is evaluated.
By comparison, with a ( A & B ) query both condition A and condition B are always evaluated.
( A | B )
Reads: if condition A OR condition B is true, then this compound query is true.
Contrast this with the |= operator (below).
( A |= B )
Reads: result is true if condition A is currently true or, if so if condition B is true.
Thus, if condition A is false, condition B is not checked and the overall result is false. Thus in some cases only condition A is evaluated.
By comparison, with a ( A | B ) query both condition A and condition B are always evaluated.
(A | B) & ( C | ( D | E ) )
This is a more complex example of logical joins. Reads: if (condition A OR condition B is true) AND (condition C OR (either condition D OR condition E are true)), then this compound query is true.
See also—notes linking to here: