I believe it's called, 'short-circuit evaluation', and applies to
binary operators like AND and OR. i.e. If you have two expressions
that evaluate to the Boolean data type, and you're using them like
If <expr1> AND <expr2> Then
the computer will check <expr1> first and - if false - won't bother
to check <expr2>. This is handy if <expr2> involves an object
reference, then <expr1> can test for the reference <> nil, thus
saving you from a NilObjectException in <expr2>! i.e.
If (myObj <> nil) And myObj.CanPerform(someTask) Then
myObj.PerformTask(someTask)
End If
as an example.
On Feb 14, 2007, at 9:23 PM, Sam DeVore wrote:
So in some languages you can test a number of things and if it
fails it doesn't test the others is this true in RB?
so like
if x<> nil and x.isEqualTo( y) then
bla bla
else
alert "x is nil"
end if
so if x is nil it jumps right to the else
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