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The `else if` Keyword Doesn’t Exist in Java

Jeremy Grifski on March 08, 2019

Listen, I know this is going to seem crazy to some of you, but the else if keyword doesn’t exist in Java. Yeah, I was today years old when I learne...

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Christian Baer • Mar 16 '19

Maybe this counts as mind blowing as well. The elif if python does not work any differently than the else if in Java. The only valid reason for having this elif construct is the formatting. In Python you would have to use correct spacing when using else if

if grade >= 90:
  print("You got an A!")
else:
  if grade >= 80:
    print("You got a B!")
  else: 
    if grade >= 70:
      print("You got a C!")
    else:
      if grade >= 60:
        print("You got a D!");
      else:
        print("You got an F!");

There is no difference in program flow or even speed when you use an elif construct. The blocks are just arranged in a nicer way. Very much like, when in Java you are using

else if(x) {
  System.out.println("Stuff")
}

instead of

else {
  if(x) {
    System.out.println("Stuff")
  }
}

The solution in your case to get 'nicer looking' code without the usage of else so much is something like:

def get_letter_grade(grade):
  if grade < 60:
    return 'F'
  if grade < 70:
    return 'D'
  if grade < 80:
    return 'C'
  if grade < 90:
    return 'B'
  return 'A'

print("Your grade: {}".format(get_letter_grade(85)))

P.S. What is wrong with you Americans? Don't you care for the alphabet? What happened to 'E'?

Jeremy Grifski • Mar 16 '19 • Edited

Maybe I was unclear, but the reason that this is so mind blowing to me is that else if isn’t a keyword. There is only elseand if. Python had to introduce a third keyword because else if isn’t valid syntax. In other words, else if comes for free in C-like languages due to the language grammar, and I had just assumed it was a special token.

Silwing • Mar 16 '19

I was just wondering to myself why python would have a separate elif keyword. But of course it makes sense because of whitespace having meaning in python.
Thanks!

Christian Baer • Mar 16 '19

Quote from python documentation to back me up on this:

The keyword ‘elif’ is short for ‘else if’, and is useful to avoid excessive indentation.

HS • Mar 17 '19

gave a heart just beacuse of P.S. :D

Ben Sinclair • Mar 27 '19

I'd never before considered that anyone would have thought of "else if" as a single keyword. I've learnt stuff today though about Python (because it would need to be else: if and that ain't gonna work) and went away to look up something else that niggled.

PHP has "elseif" as an equivalent of "else if" and I'd never understood why they'd bother (except that PHP does a lot of crazy stuff). Turns out that it's for the "colon" syntax:

if ($foo):
  // Whee!
elseif ($bar):
  // This is valid
else if ($baz):
  // This isn't
else: if ($quokka):
  // Alright calm down
endif;

Jeremy Grifski • Mar 27 '19 • Edited

Yeah, I suppose I just lumped the idea of else if as another keyword when writing branches. It never occurred to me that else and if were separate, and playing in languages like Python only reinforced that idea.

Granted, I'm sure it would have been more clear had Java not been my first language. I don't feel like you get to appreciate language syntax nowadays when languages are more tools than a form of art.

At any rate, interesting point about PHP! So, it has a mixed syntax (i.e. you can use else if with braces or elseif with a colon)?

Ben Sinclair • Mar 27 '19 • Edited

Yeah, it's mostly so you can use it in templates (since it was a templating language to begin with really):

<?php if ($foo): ?>
  <h1>Welcome to <?php echo $foo; ?></h1>
<?php else: ?>
  <h1>Welcome to something that isn't very foo</h1>
<?php endif; ?>

It's a big ugly, but it's better than this:

<?php if ($foo) { ?>
  <h1>Welcome to <?php echo $foo; ?></h1>
<?php } else { ?>
  <h1>Welcome to something that isn't very foo</h1>
<?php } ?>

Jeremy Grifski • Mar 28 '19

I can imagine that second syntax is a nightmare to debug. haha

HS • Mar 17 '19

My first reaction: of course it doesn't exist there's a space between else and if. But then again second reaction was but hey Ruby does have elsif and what's the actual reason for it. Anyway not impressed by else if part that much (i didn't actually care about those) but something similar in C# I was disappointed is switch case which works a bit different than in Java because I used to propagate steps but it's kind of bad practice so... I'm not sure about what gets me happy or mindblown except for null handling operators like elvis ?: or null coalescing ?? or conditional member acces ?. It's good to have posts like these just to make you think about stuff you don't care/notice otherwise. Thanks

Jeremy Grifski • Mar 17 '19

I'm not sure that a space necessarily indicates separate keywords. It all depends on how the grammar is written. What's stopping a language grammar from containing else if as a terminal symbol?

HS • Mar 17 '19

Nothing but my expectations are limited to that space. Even programming languages should think about UX. If you put else if as keyword with a space I wouldn't expect it to be 1 keyword but 2. But that's just my subjective view on that point.

Jilles van Gurp • Mar 18 '19

How is this a problem? Code with lots of branches is a design smell; don't do that. Also, consider using the switch statement, which is getting more powerful with recent java releases. Or better, switch to Kotlin which has a nice when statement that is a bit more sane than switch or if else garbage.

Jeremy Grifski • Mar 18 '19

I don’t think I ever said it was a problem. I was acknowledging the fact that the Java grammar doesn’t contain an else if terminal symbol. Of course, the content was geared toward beginners (i.e. my students), so I chose not to dig into compilers. Instead, I shared an example they could easily understand.

Naturally, the example is purely for the sake of argument—not something you should put in production code. Of course, you’re welcome to lecture me on which tools I should be using.