这样就算会了PHP么？-1

<?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>";
?>