AD INSERTER

/*
 * Insert ads code into post content
 * $adsCode: Specify code that wants to add
 * $insertAfter: Specify paragraph number
 */
add_filter('the_content', 'cw_insert_post_ads');
function cw_insert_post_ads($content){
    if(is_single()){
        //ads code
        $adsCode = '<div>Insert your ads code here</div>';

        //insert after
        $insertAfter = 2;

        $closingP = '</p>';
        $contentBlock = explode($closingP, $content);
        foreach($contentBlock as $key => $con){
            if(trim($con)) {
                $contentBlock[$key] .= $closingP;
            }
            if(($key + 1) == $insertAfter){
                $contentBlock[$key] .= $adsCode;
            }
        }
        $content = implode('', $contentBlock);
    }
    return $content;
}