php函数将普通换行符放入列表中

Question

I have a variable $boo that contains lines of plain text like (with singular line breaks):

a

b

c

I want a function to format it into a bullet list. Have come up with the following, but can't quiet get anything to output:

<?php
function listformat ($list) {
    $listformat = explode("
", $listformat);
    foreach ($listformat as $test => $line) {
        return "<li>".$line."</li>";
    };
};
?>

<ul>
<?php
listformat ($boo);
?>
</ul>

It works if I use echo in place of "return" and remove the function.

Answer 1

return ends your function and sends the statement back to whatever called it. So, yes, echo is necessary

<?php
function listformat ($list) {
    $listformat = explode("
", $list);
    foreach ($listformat as $line) {
        echo "<li>".$line."</li>";
    };
};

echo '<ul>';
listformat($my_list_var);
echo '</ul>';