PHP Parse error using DIRECTORY_SEPARATOR in class variable

Question

Why can I assign

$tmpPath = DIRECTORY_SEPARATOR . 'tmp' . DIRECTORY_SEPARATOR;

within a class method but get an PHP Parse error when I trie to assign it to a protected class variable like this:

protected $_tmpPath = DIRECTORY_SEPARATOR . 'tmp' . DIRECTORY_SEPARATOR;

Here is the error log:

PHP Parse error: syntax error, unexpected '.', expecting ',' or ';' in ...

Niet the Dark Absol · Accepted Answer · 2014-07-10 09:07:15Z

3

Property values must be a single, constant value, not an expression.

Unless you're using PHP5.6 in which case the code you have there is perfectly allowed.

But until you do, the typical workaround is to assign the value to it in the class's constructor.

edited Jul 10, 2014 at 9:07

answered Jul 10, 2014 at 8:03

Niet the Dark Absol

326k86 gold badges480 silver badges604 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

magic_al Over a year ago

So by single value you mean anything which has not to be evaluated to a value? So for example concatenating of stings is single value or expression then? Couldn't find a proper definition.

Niet the Dark Absol Over a year ago

Concatenation is an expression.

nl-x Over a year ago

The doc says The simplest yet most accurate way to define an expression is "anything that has a value". php.net/manual/en/language.expressions.php However that conflicts with this answer, because surely 'abcd' is also an expression and is allowed for property values PHP<5.6. Also constants are allowed for property values PHP<5.6 (EG public foo = DIRECTORY_SEPARATOR;)

nl-x Over a year ago

This is what the doc says about initializing properties: php.net/manual/en/language.oop5.properties.php

This declaration may include an initialization, but this initialization must be a constant value--that is, it must be able to be evaluated at compile time and must not depend on run-time information in order to be evaluated.

So where NietTheDarkAbsol talks about 'single values' vs 'expressions', he should say 'a constant'

Niet the Dark Absol Over a year ago

@nl-x Edited, is that better?

|

Collectives™ on Stack Overflow

PHP Parse error using DIRECTORY_SEPARATOR in class variable

1 Answer 1

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related