Adding script to the head with wp_head

<?php
/**
 * add script to head with wrapping php
 */
function addtohead_cf() {
?>
<script></script>
<?php
}
add_action('wp_head', 'addtohead_cf');
/**
 * add script to head using echo
 */
function addtohead_cf() {
echo "<script></script>";
}
add_action( 'wp_head', 'addtohead_cf' );