Basic PHP & JS questions

[apeisa]

I am reading through source code and there is some syntax that is unfamiliar to me. First in templates there is line like these:

echo "<li><a$class href='{$child->url}'>{$child->title}</a></li>";

Why there is {} around properties? Does it have any function or does it only make code cleaner?

And then at ProcessPageList.js there is lines like this:

if(child.status & 1024) $li.addClass('PageListStatusHidden secondary'); 

What does & at that line? I have a good guess, but I have never seen that syntax before so better ask than assume

This probably isn't best forum for such a general programming questions, but it would really help me to understand what is happening under the hood (and of course learn some new programming at the same time).

[Adam Kiss]

Hi Apeisa,

welcome to the forums, although google is your friend in this case, I'll be easy on you

{} brackets

Is so called Complex syntax. It allows you to use more complicated $values in parsed strings, consider following:

	echo "$arr['foo'][4]";

throws syntax error, unexpected T_ENCAPSED_AND_WHITESPACE

	echo "{$arr['foo'][4]}";

on the other hand, will work, because the curly brackets delimited parts of string, that should be considered as $variable.

More here: http://www.php.net/manual/en/language.types.string.php#language.types.string.parsing.complex

P.S.: even simple parsing can parse objects ($object->property), but I think Ryan considers it best practice to use curly brackets (not to mention it also increases readability)

& operator

Amp in this case is so called Bitwise And.

You can read about it here: http://www.php.net/manual/en/language.operators.bitwise.php

In this case, it compares two int values – page.status and value 1024. is page.status has the '1024' bit set (= if page.status value is 1 in binary form on 2¹⁰th place) it continues.

[apeisa]

Thank you Adam!

I tried Google (as always), but as non native English speaker I have sometimes difficulties to find right queries when it comes to special characters. Google tends to ignore single characters like { and &

[Adam Kiss]

Glad to help, stick around

Btw, for future reference (to better yourself at google searching )

complex syntax: http://lmgtfy.com/?q=curly+brackets+parsed+strings+php

& operator: http://lmgtfy.com/?q=single+amp+operator+php

in both cases, first links provide better understanding of things mentioned