A simple word guessing game_PHP tutorial

I forgot where I saw this game. I remembered it before going to bed and wrote it immediately,
I don’t have any good ideas, and I don’t pursue styles or anything like that,
I used SESSION with AJAX,
Little coder, please give me some advice and guidance,
PS: Not much optimization, don’t complain,
Just copy it locally and run it,

<?php
session_start();
header("Content-type:text/html;charset=utf-8");
$url=&#39;http://&#39;.$_SERVER[&#39;HTTP_HOST&#39;].$_SERVER[&#39;PHP_SELF&#39;];
function get_word(){
	$wordtext="Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. Neither the name of Yii Software LLC nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS AS IS AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.";
	$words=preg_split("/[\s,]+/",$wordtext);
	do{
		$i=rand(0,count($words)-1);
		$word=strtoupper($words[$i]);
	}while(strlen($word)<5 || !ctype_alpha($word));
	return $word;
}
function guess($word){
	return str_repeat(&#39;_&#39;,strlen($word));
}
function output($word){
	$str=&#39;&#39;;
	for($i=0;$i<strlen($word);$i++){
		$str.=$word[$i]." ";
	}
	return rtrim($str);
}
if(isset($_GET[&#39;op&#39;]) && $_GET[&#39;op&#39;]==&#39;start&#39;){
	$k=$_GET[&#39;k&#39;];
	$_SESSION[&#39;num&#39;]=$k;
	exit;
}
if(isset($_GET[&#39;restart&#39;]) && $_GET[&#39;restart&#39;]==1){
	session_unset();
	header("location:$url");
	exit;
}
if(!isset($_SESSION[&#39;word&#39;])){
	$word=get_word();
	$_SESSION[&#39;word&#39;]=$word;
}else{
	$word=$_SESSION[&#39;word&#39;];
}
$guess_word=guess($word);
if(isset($_GET[&#39;op&#39;]) && $_GET[&#39;op&#39;]==&#39;ajax&#39;){
	$k=$_GET[&#39;k&#39;];
	$re=&#39;&#39;;
	if(!isset($_SESSION[&#39;already&#39;])){
		$_SESSION[&#39;already&#39;]=guess($_SESSION[&#39;word&#39;]);
	}
	if(!isset($_SESSION[&#39;count&#39;])){
		$_SESSION[&#39;count&#39;]=0;
	}
	if(strpos($_SESSION[&#39;word&#39;],$k)!==false){
		for($i=0;$i<strlen($_SESSION[&#39;word&#39;]);$i++){
			if($_SESSION[&#39;word&#39;][$i]!=$k){
				$re.=&#39;_&#39;;
			}else{
				$re.=$_SESSION[&#39;word&#39;][$i];
			}
		}
		for($i=0;$i<strlen($_SESSION[&#39;word&#39;]);$i++){
			if($_SESSION[&#39;already&#39;][$i]==&#39;_&#39;){
				$_SESSION[&#39;already&#39;][$i]=$re[$i];
			}
		}
	}else{
		$_SESSION[&#39;count&#39;]+=1;
	}
	$return=output($_SESSION[&#39;already&#39;]);
	if($_SESSION[&#39;count&#39;] <= $_SESSION[&#39;num&#39;]){
		if($_SESSION[&#39;already&#39;]==$_SESSION[&#39;word&#39;]){
			$return.="|1";
		}else{
			$return.="|0";
		}
	}else{
		$return.="|2";
	}
	echo $return;
	exit;
}
?>
<script>
function Ajax(recvType){
    var aj=new Object();
    aj.recvType=recvType ? recvType.toUpperCase() : &#39;HTML&#39;;
    aj.targetUrl=&#39;&#39;;
    aj.sendString=&#39;&#39;;
    aj.resultHandle=null;
    aj.createXMLHttpRequest=function(){
        var xmlHttp = false;
        if(window.XMLHttpRequest){
            xmlHttp = new XMLHttpRequest();
        }else if(window.ActiveXObject){
            try{
                xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
            }catch(error1){
                try{
                    xmlHttp = new ActiveXobject("Microsoft.XMLHttp");
                }catch(error2){
                    xmlHttp = false;
                }
            }
        }
        return xmlHttp;
    }
    aj.XMLHttpRequest=aj.createXMLHttpRequest();
    aj.processHandle=function(){
        if(aj.XMLHttpRequest.readyState == 4){
            if(aj.XMLHttpRequest.status == 200){
                if(aj.recvType=="HTML"){
                    aj.resultHandle(aj.XMLHttpRequest.responseText);
                }else if(aj.recvType=="XML"){
                    aj.resultHandle(aj.XMLHttpRequest.responseXML);
				}
            }
        }
    }
    aj.get=function(targetUrl, resultHandle){
        aj.targetUrl=targetUrl;
        if(resultHandle!=null){
            aj.XMLHttpRequest.onreadystatechange=aj.processHandle;
            aj.resultHandle=resultHandle;
        }
        if(window.XMLHttpRequest){
            aj.XMLHttpRequest.open("get", aj.targetUrl);
            aj.XMLHttpRequest.send(null);
        }else{
            aj.XMLHttpRequest.open("get", aj.targetUrl, true);
            aj.XMLHttpRequest.send();
        }
    }
    return aj;
}
</script>
<script>
var ajax=Ajax();
function select(v){
	document.getElementById(v).style.display=&#39;none&#39;;
	ajax.get("guess.php?op=ajax&k="+v, function(r){
		var t=r.split("|");
		document.getElementById(&#39;word&#39;).innerHTML=t[0];
		if(t[1] == 1){
			document.getElementById(&#39;select&#39;).style.display=&#39;none&#39;;
			document.getElementById(&#39;result&#39;).innerHTML=&#39;成功&#39;;
		}else if(t[1] == 2){
			document.getElementById(&#39;select&#39;).style.display=&#39;none&#39;;
			document.getElementById(&#39;result&#39;).innerHTML=&#39;失败&#39;;
		}
	});
}
function check(v){
	ajax.get("guess.php?op=start&k="+v, function(r){
		window.location.href="<?php echo $url;?>";
	});
}
</script>
<?php
if(!isset($_SESSION[&#39;num&#39;])){
	echo &#39;<input type="radio" onclick="check(10);" /> easy: wrong 10<br />&#39;;
	echo &#39;<input type="radio" onclick="check(5);" /> normal: wrong 5<br />&#39;;
	echo &#39;<input type="radio" onclick="check(3);" /> hard: wrong 3<br />&#39;;
}else{
	//echo $word;
	echo "最多可以猜错 ".$_SESSION[&#39;num&#39;]." 次";
	echo "<br />";
	echo "<div id=&#39;word&#39;>";
	echo output($guess_word);
	echo "</div>";
	echo &#39;<br />&#39;;
	echo &#39;<div id="select">&#39;;
	for($i=ord(&#39;A&#39;);$i<=ord(&#39;Z&#39;);++$i){
		echo "\n";
		$letter=chr($i);
		echo &#39;<span id="&#39;.$letter.&#39;" style="display:"><a href="javascript：void(0);" onclick="select(\&#39;&#39;.$letter.&#39;\&#39;);">&#39;.$letter.&#39;</a></span>&#39;;
	}
	echo &#39;</div>&#39;;
	echo &#39;<br />&#39;;
	echo &#39;<br />&#39;;
	echo &#39;<div id="result"></div>&#39;;
	echo &#39;<br />&#39;;
	echo &#39;<br />&#39;;
	echo &#39;<a href="&#39;.$url.&#39;?restart=1">重新开始</a>&#39;;
}
?>

http://www.bkjia.com/PHPjc/444579.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/444579.htmlTechArticleI forgot where I saw this game. I wrote it immediately when I remembered it before going to bed. I didn’t have any good ideas. , I don’t care about the style. I used SESSION and AJAX to make it. I am a young coder, please give me some advice...