Else is an adverb which in your phrase could be rewritten as someone different's (or instead's). There is no plural form for an adverb so elses and elses' are always wrong.
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.
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.
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.
"One option is to code the else clause—with a null statement if necessary—to show that the else case has been considered. Coding null elses just to show that that case has been considered might be overkill, but at the very least, take the else case into account.
The conditional coding IS actually the IF/ELSE statement. The issue is the ELSE part is not built in. To solve your issue, you need something to hide the content you no longer want MSO to use but show up in all other clients. This can be handled either through conditional classes (in the if statement) OR, as you mentioned you did not want to use classes, you can use the mso-hide:all css that ...
