021-PHP常用的数值类型判断函数

<?php
    //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>");
    }
?>