Simple and Superior Function for Adding Adsense Code to WordPress Posts

A good Adsense injection function will place ads at the right places by taking into account word count without counting HTML markup and by prioritizing user experience.

Objective

In this post, I will walk you through the process of creating my best function for inserting Adsense code into WordPress posts.

The function will meet the following requirements:

1. Inserts ads for posts, pages, custom post types, or all
2. Inserts an ad after n-words without counting HTML markup
3. Inserts ads after a paragraph’s closing tag
4. Can be used in the_content hook or directly in a template.
5. Its portable and simple.

<?php
add_action('the_content', function($content) { 
    if (!is_single()) {         
       return $content; 
    }
    if(!$content) {     
       return $content; 
    } 
    $chunks = explode('</p>', $content); 
    $counter = 0; 
    for($i = 0; $i < count($chunks); $i++) {     
        $counter += str_word_count(strip_tags($chunks[$i]));     
        if( $counter > 4) {         
            $chunks[$i] .= ARTICLE_AD;         
            $counter = 0;     
        } 
    }     
    return implode("", $chunks); 
});

If you would also like to insert an ad at the end of the content, then I have a different version of the function to account for situations where the 4-word count happens to be at the end of the content, resulting in two ad placements at the end of the content.