<HTML>
<HEAD>
<TITLE>php常用的数值判断函数</TITLE>
</HEAD>
<BODY>
<?
//判断数组
$colors = array("red", "blue", "green");
if(is_array($colors))
{
print("colors is an array"."<br>");
}
//双精度数判断
$Temperature = 15.23;
if(is_double($Temperature))
{
print("Temperature is a double"."<br>");
}
//整数判断
$PageCount = 2234;
if(is_integer($PageCount))
{
print("$PageCount is an integer"."<br>");
}
//对象判断
class widget
{
var $name;
var $length;
}
$thing = new widget;
if(is_object($thing))
{
print("thing is an object"."<br>");
}
//字符判断
$Greeting = "Hello";
if(is_string($Greeting))
{
print("Greeting is a string"."<br>");
}
?>
</BODY>
</HTML>
原文：http://www.jb51.net/article/15578.htm