<?php function say_hello() //无参数{    $name="tang";    echo "hello,".$name;    echo "<br />";    echo "<hr />";}say_hello();//函数调用function say_helloS($some_name)//有参数{    echo "hello,".$some_name;    echo "<br/>";    echo "<hr />";}say_helloS("tang");say_helloS("xue");say_helloS("long");function say_helloT($some_name="tangwei")//带有默认参数的函数{    echo $some_name." is god girl!";}say_helloT();?>