What is the difference between l() and url()?

Question

Why does Drupal provide l() and url(), which seems to have the same purpose?

Answer 1

l() creates a clickable link (an HTML anchor tag), while url() creates just a url. If you scroll down in the l() page you'll see the following source code:

  if ($use_theme) {
    return theme('link', array('text' => $text, 'path' => $path, 'options' => $options));
  }
  // The result of url() is a plain-text URL. Because we are using it here
  // in an HTML argument context, we need to encode it properly.
  return '<a href="' . check_plain(url($path, $options)) . '"' . drupal_attributes($options['attributes']) . '>' . ($options['html'] ? $text : check_plain($text)) . '</a>';

theme_link() has a similar construction. So l() is using url() to construct the anchor.

So summarizing, the one is for clickable links, the other for plain (unclickable) url's.

Answer 2

If I've understood the documentation correctly, function url($path = NULL, array $options = array()) returns a string, which is URL of given path.

Whereas function l($text, $path, array $options = array()) has an advanced parameter $text and returns an html anchor with given text, given path and options.