In PHP can you use || (or) in the same way as javascript?

Question

Can I use the OR argument in this way in PHP? Meaning if $x is null assign $y to $var.

$var = $x || $y

Simple question, cheers!

I was hoping it would enlighten me on the best practices for this type of scenario, and it has. This question will also act as reference for others. — wilsonpage, Jul 06 '11 at 09:09
For a reference, see http://stackoverflow.com/questions/3737139/reference-what-does-this-symbol-mean-in-php — KingCrunch, Jul 06 '11 at 09:14

score 8 · Accepted Answer · answered Jul 06 '11 at 08:58

No. PHP's boolean operators evaluate to true or false, not the value of the operands as in Javascript. So you'll have to write something like this:

$var = $x ? $x : $y;

Since 5.3, you can write this though, which basically has the same effect as Javascript's ||:

$var = $x ?: $y;

That requires that $x exists though, otherwise you should check with isset first.

score 3 · Answer 2 · answered Jul 06 '11 at 08:57

No, in this way you assign a boolean to $var

$var = $x or $y;

means: $var is true, if $x or $y. You are looking for the ternary operator

$var = isset($x) ? $x : $y;
// or
$var = empty($x) ? $y : $x;

The ternary operator always works like

$var = $expressionToTest
     ? $valueIfExpressionTrue
     : $valueIfExpressionFalse

With PHP5.3 or later you can omit $valueIfExpressionTrue

$var = $expressionToTest ?: $valueIfExpressionFalse;

score 1 · Answer 3 · answered Jul 06 '11 at 08:59

1

$x=0;
$y=9;
$var = ($x)?$x:$y;

echo $var;

if variable x is null then var will be 9,or else it will be value of x.

answered Jul 06 '11 at 08:59

Mithun Satheesh

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score 0 · Answer 4 · answered Jul 06 '11 at 09:24

This question is already answered, but I juist wanted to point your attention to the other usage of OR and AND operators in PHP

defined('SOMETHING') OR define('SOMETHING', 1);

if this case if SOMETHING is not defined (defined('SOMETHONG') evaluates to false) expression after OR will be evaluated

$admin AND show_admin_controls();

if $admin is evaluated to boolean true, show_admin_controls() function will be called

I usually use it to check if some constant is defined, but I've seen a lot of examples of good-looking and really well-readable code using this constructions for other purposes.

In PHP can you use || (or) in the same way as javascript?

4 Answers4