and / or keywords

 

Is && the same as "and", and is || the same as "or" in PHP?

I've done a few tests, and it seems they behave the same. Are there any differences?

If not, are there any other PHP signs that have word equivalents and do you think it makes the code easier to read?

and and or have higher lower precedence than && and || . To be more exact && and || have higher precedence than assignment operator ( = ) while and and or have lower.

http://www.php.net/manual/en/language.operators.precedence.php

Usually it doesn't make a difference, but there are cases when not knowing about this difference can cause some unexpected behaviour. See examples here:

http://php.net/manual/en/language.operators.logical.php

Yes, they are logically the same. (I believe "&&" and "||" are the preferred choice in the Zend coding standards, but I can't find any specific information on this, so it might all have been a dream. Or something.)

That said:

  • "&&" and "||" are of a higher precedence than "AND" and "OR" (unlikely to ever be relevant, but you never know).

  • A lot of other languages use "&&" and "||", rather than the textual equivalents so it might be an idea to go with this.

  • As long as you use your choosen set of operators consistently it doesn't really matter.

    • What bothers me is: 

    echo (false and false ? true : true);
// (empty/false)

    You might guess there is only the possible output of "1" (true) as there is no case which could output a false... ...but it will be "" (false).

    Using && as a operator in this case satifies at least my expectations: 

    echo (false && false ? true : true);
// 1

    So, in some cases the usage matters significantly.

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