To Nest or Not to Nest Else

[Dimster]

I think Terry your nested IF statements would only perform the next test IF the last one was true. Otherwise, as you point out, IF any of the conditions test False no other conditions are tested.

I'm thinking if your code did include Else in the nesting then I think all the conditions would be tested...I think... 


IF R1.right >= R2.left THEN '            check for overlapping coordinates
   Else
     IF R1.left <= R2.right THEN
       Else
            IF R1.bottom >= R2.top THEN
               Else
                   IF R1.top <= R2.bottom THEN ' all checks passed, must be a collision
                    RectCollide% = -1 '                return that a collision was detected (TRUE)
                END IF
            END IF
        END IF
    END IF


IF R1.right >= R2.left THEN '            check for overlapping coordinates
ElseIF R1.left <= R2.right THEN
ElseIF R1.bottom >= R2.top THEN
ElseIF R1.top <= R2.bottom THEN ' all checks passed, must be a collision
                    RectCollide% = -1 '                return that a collision was detected (TRUE)
END IF
   

Both Else and ElseIF would test each condition, without the Else or ElseIF conditions are tested until a False is incurred....I thinks that's correct. Your code would short circuit the IF run and that could save a lot of time in processing