How to replace dynamic string?

Question

I have variable $menu type array like below:

$menu = array('<li class="page_item page-item-155">',
              '<li class="page_item page-item-49">',
              '<li class="page_item page-item-72">',
              '<li class="page_item page-item-18">',
              '<li class="page_item page-item-50">');

I want to replace the first original string

<li class="page_item page-item-155">'

to

<li class="current">

In the end of the string it can be any number, the numbers are not constant.

I think I need to use a regular expression but I don't know how to implement it.

$menu = str_replace($original_strs_array, $replacement_strs_array, $menu);

How can I do that? Thanks.

Have you considered using an XML parser for whatever it is you're doing? — Waleed Khan, Oct 02 '12 at 20:02
Just replace `-X"` with `-X current"`, where `X` is current selected menu. No need to replace class names. — Glavić, Oct 02 '12 at 20:04
@deizel: I am not sure that this is what eh wants. Variable $menu is array, so does he wants to replace every value? Or just the selected $menuId ? — Glavić, Oct 02 '12 at 20:11
@glavić I presume he has the ID, so just your str_replace in a foreach? (using $id instead of X) — deizel., Oct 02 '12 at 20:13
@deizel: That is the problem, he hasn't told what he wants exactly. And you do not need `foreach()`, because 3rd parameter in `str_replace()` will accept array. — Glavić, Oct 02 '12 at 20:16

Glavić · Accepted Answer · 2012-10-02T20:31:32.287

Code

All $menu values: replace class="*" with class="current"

$menuA = preg_replace('~class=".+"~', 'class="current"', $menu);
print_r($menuA);

All $menu values: add className "current" to the current class

$menuB = preg_replace('~class="(.+?)"~', 'class="$1 current"', $menu);
print_r($menuB);

Selected menu: replace class="*" with class="current"

$menuC = preg_replace('~class=".*?page-item-'.$selectedMenuId.'"~', 'class="current"', $menu);
print_r($menuC);

Selected menu: add className "current" to the current class

$menuD = preg_replace('~class="(.*?)page-item-('.$selectedMenuId.')"~', 'class="$1page-item-$2 current"', $menu);
print_r($menuD);

Output

$menuA = Array
(
    [0] => <li class="current">
    [1] => <li class="current">
    [2] => <li class="current">
    [3] => <li class="current">
    [4] => <li class="current">
)
$menuB = Array
(
    [0] => <li class="page_item page-item-155 current">
    [1] => <li class="page_item page-item-49 current">
    [2] => <li class="page_item page-item-72 current">
    [3] => <li class="page_item page-item-18 current">
    [4] => <li class="page_item page-item-50 current">
)
$menuC = Array
(
    [0] => <li class="page_item page-item-155">
    [1] => <li class="page_item page-item-49">
    [2] => <li class="current">
    [3] => <li class="page_item page-item-18">
    [4] => <li class="page_item page-item-50">
)
$menuD = Array
(
    [0] => <li class="page_item page-item-155">
    [1] => <li class="page_item page-item-49">
    [2] => <li class="page_item page-item-72 current">
    [3] => <li class="page_item page-item-18">
    [4] => <li class="page_item page-item-50">
)

if `$menu` will be string not array and I want to replace just in the first tag `li`, How can I convet it to `class="current"` ? Thanks . — yossi, Oct 02 '12 at 20:33
Just add `1` in the 4th parameter of the `preg_replace()` function, no matter if `$menu` is string or array. — Glavić, Oct 02 '12 at 20:37

Ariyan · Answer 2 · 2012-10-02T20:43:39.787

1

try this :

preg_replace('/page_item page-item-\d+/','current',$menu);

Or this for a generic class remover/replacer:

preg_replace("/class\s*=\s*('|\")[^'\"]*('|\")/",'class="current"',$menu);

edited Oct 02 '12 at 20:43

answered Oct 02 '12 at 20:05

Ariyan

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.. or just `\d+` (if you are doing a comparison with the matching number). – deizel. Oct 02 '12 at 20:06
@deizel: he wants to replace `page_item page-item-` too – Ariyan Oct 02 '12 at 20:11
1

True, but there is probably no need when the extra class can just be added. :) – deizel. Oct 02 '12 at 20:14
@deizel: Yes he can add class by Javascript and override CSS (if its needed) and forget all these. but he asked a PHP replacement question and I answered like that! ;-) – Ariyan Oct 02 '12 at 20:16