Wordpress using echo vs return in shortcode function

Question

I noticed both echo and return works fine for displaying content from a shortcode function in wordpress.

function foobar_shortcode($atts) {
    echo "Foo Bar"; //this works fine
}

function foobar_shortcode($atts) {
    return "Foo Bar"; //so does this
}

Is there any difference between using either of these? If yes, what's the recommended approach for wordpress? I normally use echo in this case - is this okay?

Answer 1

If you are outputting a lot of contents, then you should use:

add_shortcode('test', 'test_func');

function test_func( $args ) {
  ob_start();
  ?> 
  <!-- your contents/html/(maybe in separate file to include) code etc --> 
  <?php

  return ob_get_clean();
}