No true, because with such syntax else if is side-effect (i.e. it comes for free). In other words there is no else if syntax, there is only if and else here.
But if the chain of the related If's occur inside of a function and each would execute a [return] statement, then the net effect of multiple if's matches using else if. However, it'd still be better practice to use [else if] whenever it doesn't make sense to test for the next condition, if the previous one was true.
Looks like an old question, however if I understood your question and thought correctly, you want to implement the if/else conditional statement in SQL. Both are calculated as a separate column.
One reason very old languages use this distinct syntax instead of "else if" is that the "else if" introduces a grammar ambiguity. Old parser generators were hard to teach about what to do for ambiguities, so we avoided them.
In your case, whether you need an else clause depends on whether you want specific code to run if and only if neither of condition1, condition2, and condition3 are true. else can be omitted for any if statement, there is nothing special in the last if of an if / else if chain. This is documented in any JavaScript grammar, e.g. in the specification.
I am sure there is some problem in BEGIN;END or in IF EXIST;ELSE. Basically I want to by-pass the else part if select statement in IF-part exist and vice- versa.
Then R reads the first line and because it is complete, runs that in its entirety. When it gets to the next line, it goes "Else? Else what?" because it is a completely new statement. To have R interpret the else as part of the preceding if statement, you must have curly brackets to tell R that you aren't yet finished:
If it is A.do(int condition) -- If .. else ... else, can not all happen as a result of one call. Flow depends on the condition argument. It would be lovely if ZenUML could draw that. It would be three calls ordered in time.
