Wordpress php function does not return value

Question

I'm trying to write a PHP function for my WordPress theme that will return the number of categories for a given post. I'm using two files: functions.php and header.php

Contents of functions.php:

/**
*   Category count for a given post (post ID) excluding given excludecats (array).  
*   @return number
*/
function bl_cat_count($pid,$excludedcats) {
    $cat_count = 0;
    //$count = 0;
    $categories = get_the_category($pid);
    foreach($categories as $category) { 
        $cat_count++;
        if ( in_array($category->cat_ID, $excludedcats) ) {
            $cat_count--;
        } 
    }
    var_dump($cat_count);
    return $cat_count;
}

Contents of header.php:

$pid = $thumbnail->ID;
$excludedcats = array(1,85);
bl_cat_count($pid,$excludedcats);                          
var_dump($cat_count);
if ( $cat_count > 0 ) {
  // do something
}

var_dump on the function reveals the correct value. When calling from header.php however var_dump shows null. Maybe I've been looking at it for too long but I can't figure out why.

Shankar Narayana Damodaran · Accepted Answer · 2014-01-01 04:01:23Z

2

Change your header.php like this...

$cat_count=bl_cat_count($pid,$excludedcats);                          
var_dump($cat_count);

Why it threw null ?

That is because , you are not assigning the value returned by the bl_cat_count() to your $cat_count variable. Also , $cat_count variable's scope is within that function i.e. bl_cat_count() !

answered Jan 1, 2014 at 4:01

Shankar Narayana Damodaran

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1 Comment

Ohgodwhy Over a year ago

expanding upon this, the issue is the scope of the variable. If you defined that variable outside of your bl_cat_count function, then you could access it from header.php.

Giacomo1968 · Accepted Answer · 2014-01-01 04:29:54Z

0

Look at this:

$pid = $thumbnail->ID;
$excludedcats = array(1,85);
bl_cat_count($pid,$excludedcats);                     
var_dump($cat_count);
if ( $cat_count > 0 ) {
  // do something
}

So bl_cat_count is the function? And $cat_count contains the returned result of the function? So where does $cat_count get assigned?

answered Jan 1, 2014 at 4:29

Giacomo1968

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