吴裕雄--天生自然 PHP开发学习：函数

<?php
function writeName()
{
    echo "Kai Jim Refsnes";
}
 
echo "My name is ";
writeName();
?>

<?php
function writeName($fname)
{
    echo $fname . " Refsnes.<br>";
}
 
echo "My name is ";
writeName("Kai Jim");
echo "My sister's name is ";
writeName("Hege");
echo "My brother's name is ";
writeName("Stale");
?>

<?php
function writeName($fname,$punctuation)
{
    echo $fname . " Refsnes" . $punctuation . "<br>";
}
 
echo "My name is ";
writeName("Kai Jim",".");
echo "My sister's name is ";
writeName("Hege","!");
echo "My brother's name is ";
writeName("Ståle","?");
?>

<?php
function add($x,$y)
{
    $total=$x+$y;
    return $total;
}
 
echo "1 + 16 = " . add(1,16);
?>