php学习之旅 (6) 函数

php的强大主要得益于函数,php中有超过700个的内置函数.
我主要介绍的是php的自定义函数
关于php的内置函数,大家可以去这里看看[url]http://www.w3schools.com/php/default.asp[/url]

1.简单函数

<?php
function writeName()
{
echo "Kai Jim Refsnes";
}

echo "My name is ";
writeName();
?>

输出 My name is Kai Jim Refsnes

2.带参数的函数

<?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","?");
?>

输出
My name is Kai Jim Refsnes.
My sister's name is Hege Refsnes!
My brother's name is Ståle Refsnes?


3.有返回值的函数

<?php
function add($x,$y)
{
$total=$x+$y;
return $total;
}

echo "1 + 16 = " . add(1,16);
?>

输出
1 + 16 = 17