<?
function _pr()
{
echo "这是一个自定义函数";
}
_pr();
function woaini($a)
{
if ($a==3)
{
echo "这个是3";
}
else {
echo "不是3";
}
}
$a=_pr();
echo $a;
$b=90;
function _yige($val1,$val2=3)
{
global $b;
$a=$val1+$val2+$b;
return $a."val1是:".$val1."val2是:".$val2;
}
$b=_yige(2,5);
echo $b;
?>
function _pr($a;&$b); //引用返回值;
-------------------------------------------------
<?
echo "";
if (function_exists('_yige')) /// 判断函数是否存在
{
echo "zhen";
}else
{
echo "jia";
}
?>
<?
echo "
";
?>
运行结果显示: