<?php    $boo=true;    if($boo==true)        echo ‘变量$boo为真！‘;    else        echo ‘变量$boo为假！‘;    echo "<p>";    $i = ‘只会看到一遍‘;    echo "$i";    echo "<p>";    echo ‘$i‘;    echo "<p>";    $str1 = 1234567890;    $str2 = 0x1234567890;    $str3 = 01234567890;    $str4 = 01234567;    echo ‘数字1234567890不同进制的输出结果：<p>‘;    echo ‘十进制的结果是:‘.$str1.‘<br>‘;    echo ‘十六进制的结果是：‘.$str2.‘<br>‘;    echo ‘八进制的结果是:‘;    if($str3 == $str4){        echo ‘$str3 = $str4 = ‘.$str3;    }else{        echo ‘$str3 !- str4‘;    }    $arr1 = array(‘this‘,‘is‘,‘a‘,‘example‘);    $arr2 = array(0=>‘php‘,1=>‘is‘,‘the‘=>‘the‘,str =>‘best‘);    $arr3[0] = ‘tmpname‘;    echo "<p>";    echo $arr1[1];    echo $arr2[‘str‘];    echo $arr3[0];    echo "<p>";    echo "变量(\$string1)直接被赋值为Null:";    $string1 = null;    if(is_null($string1))        echo "string1 = null";        echo "<p>";        $num = ‘3.1415926r*r‘;        echo ‘使用(integer)操作符转换变量$num类型:‘;        echo (integer)$num;        echo "<p>";                $boo = "03563562345245";        if(is_numeric($boo))            echo "Yes, the \$boo is a phone number:$boo!";        else            echo "Sorry, This is an error!";                    echo "<p>";        define ("MESSAGE","能看到一次");        echo MESSAGE."<BR>";        echo "<p>";        echo Message."<BR>";        echo "<p>";        define ("COUNT","能看到多次",true);        echo COUNT."<br>";        echo "<p>";        echo Count."<BR>";        echo "<p>";        $name = "count";        echo constant($name)."<BR>";        echo (defined("MESSAGE"))."<BR>";        echo "<p>";        echo "当前文件路径: " .__FILE__;        function zdy(){            static $message = 0;            $message += 1;            echo $message." ";        }        function zdy1(){            $message = 0;            $message += 1;            echo $message." ";        }        for ($i = 0; $i <  10; $i++) zdy();        echo "<br>";        for ($i = 0; $i < 10; $i++) zdy1();        echo "<br>";?>