How to put Specific text in every post at beginning as well as Ending?

Question

I am currently using this code, which shows the code beginning of every post. I want to show code in the Beginning and Ending of every post. Can anyone help with this?

add_filter( 'the_content', 'filter_the_content_in_the_main_loop' );
function filter_the_content_in_the_main_loop( $content ) {

    // Check if we're inside the main loop in a single post page.
    if ( is_single() && in_the_loop() && is_main_query() ) {

       return esc_html__("So Friends, How is our Article of ".get_the_title().". Do You Like it? Don't Forget to Comment below if Any Queries. For More Article regarding ".get_the_title()." Subscribe Us.").$content;
    }

    return $content;
}

Answer 1

You already know the answer. In "the_content" filter you are prepending some text to the $content variable. Now what you want to do is append. Ex:

add_filter( 'the_content', 'filter_the_content_in_the_main_loop' );
function filter_the_content_in_the_main_loop( $content ) {

    // Check if we're inside the main loop in a single post page.
    if ( is_single() && in_the_loop() && is_main_query() ) {
       return "Beginning text" .$content . "Ending Text";
    }

    return $content;
}

"Beginning text" is the text that you have already added.

[2020 Jan 07]: Per OP request adding code snippet to change based on the pos category.

add_filter( 'the_content', 'filter_the_content_in_the_main_loop' );
function filter_the_content_in_the_main_loop( $content ) {

    // Check if we're inside the main loop in a single post page.
    if ( is_single() && in_the_loop() && is_main_query() ) {
    //get categories
        $categories = get_the_category();
        foreach($categories as $category){
            //you can check by term_id, name, slug
            if($category->$term_id == $target_term_id){
                return "Beginning text" .$content . "Ending Text";
            }
        }
    }

    return $content;
}