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Comment by Mithaldu | Hacker News Reader

I don't like PHP either, but that doesn't mean kneejerk reactions are excusable, and at the least on the first point you are wrong. Using | instead of || is not an inconsistency, but actually quite consistent.

|| is a short-cutting or comparison operator which returns the first true thing it encounters.

| is a bitwise or combinator, which takes two sets of flags, and combines them into one set of flags that has all flags activated which were also active in the input sets.

Semantically, | is absolutely the correct choice here.

A better question would be why there's a $2 there, though i hope that's just a typo and means $e.

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> || is a short-cutting or comparison operator which returns the first true thing it encounters.

I wish. The fact that it actually doesn't is one of the things that really bugs me about PHP:

    <?php
    var_dump(0 || 42);

The above example will output:

    bool(true)

... ok, i gotta admit i had my Perl hat on for that reply.

You were actually correct -- see my above reply.

PHP does have the shorthand ternary operator `?:`, though, which does what you want here:

  $ php -r 'var_dump(0 || 42);'
  bool(true)
  $ php -r 'var_dump(0 ?: 42);'
  int(42)

Wow. OK, I am a big user of the ternary operator, but I hadn't come across omission of the middle part until now. To be honest, it's not the most accessible syntax (especially if you're coming from another language), but at least I have the option now - thanks!

edit: Just to clarify for anyone else unfamiliar with it:

    $ php -r 'var_dump(42 ?: 0);'
    int(42)

Depending on how far back you have to support (e.g., WordPress is still supporting 5.2), omission of the middle part wasn't supported until PHP 5.3.

5.3 came out seven years ago and isn't even officially supported by the PHP project now, let alone 5.2.

I know all too well, and you'd never catch me running that on any of my own systems. With a large enough install base, it's not uncommon to have a decent number of people on those older versions though.

Actually || is short circuiting and behaves exactly as he described, it returns the first true thing it encounters.

  $ php -a
  Interactive shell
  
  php > echo 1 || die('die');
  1

This echo's 1, it doesn't die.

This is correct. PHP makes extensive use of bitwise operators for function options. For examples, see json_encode, htmlentities, filter_input, etc.

I didn't understand why the remark was there at all. Honestly | reminds me of sum types and it's the perfect choice here.

The reason I added this was because most developers are used to using a double pipe when writing code that has 'or' conditions.

I understand the use of pipes for bitwise, but in this case if you read the code in the example, we're basically saying "if the exception is of type A or of type B", personally I'd be inclined to use || if I didn't already know the syntax.

Indeed it was a typo, i've now fixed that in the article. Thanks.

Better yet, don't reinvent the world and just use commas?

Commas would require changing the syntax and implementation of catch. This way exception names just become first class subjects that can be combined with an overloaded operator.

Commas are used in PHP as a sequence of things, not multiple options. This single-pipe notation is already established as the further-up comments states.

> Commas are used in PHP as a sequence of things

Choosing a pipe because it's easier for an obscure language feature, is not least astonishment. Commas are used for lists. The pipe is a bad choice among a nice feature.

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