第一种：

在网站底部footer.php中添加以下代码

<!-- 次数统计 start -->
<center>
<script>
var caution = false
        function setCookie(name, value, expires, path, domain, secure) {
            var curCookie = name + "=" + escape(value) + ((expires) ? "; expires=" + expires.toGMTString() : "") + ((path) ? "; path=" + path : "") + ((domain) ? "; domain=" + domain : "") + ((secure) ? "; secure" : "")
            if (!caution || (name + "=" + escape(value)).length <= 4000)
                document.cookie = curCookie
            else if (confirm("Cookie exceeds 4KB and will be cut!"))
                document.cookie = curCookie
        }
        function getCookie(name) {
            var prefix = name + "="
            var cookieStartIndex = document.cookie.indexOf(prefix)
            if (cookieStartIndex == -1)
                return null
            var cookieEndIndex = document.cookie.indexOf(";", cookieStartIndex + prefix.length)
            if (cookieEndIndex == -1)
                cookieEndIndex = document.cookie.length
            return unescape(document.cookie.substring(cookieStartIndex + prefix.length,
                cookieEndIndex))
        }
        function deleteCookie(name, path, domain) {
            if (getCookie(name)) {
                document.cookie = name + "=" + ((path) ? "; path=" + path : "") + ((domain) ? "; domain=" + domain : "") + "; expires=Thu, 01-Jan-70 00:00:01 GMT"
            }
        }
        function fixDate(date) {
            var base = new Date(0)
            var skew = base.getTime()
            if (skew > 0)
                date.setTime(date.getTime() - skew)
        }
        var now = new Date()
        fixDate(now)
        now.setTime(now.getTime() + 730 * 24 * 60 * 60 * 1000)
        var visits = getCookie("counter")
        if (!visits)
            visits = 1
        else
            visits = parseInt(visits) + 1
        setCookie("counter", visits, now)
        document.write("<font size=2color=black>欢迎您，您是第：" + visits + " 个访问该站点的访客")

    </script>
    </center>
<!-- 次数统计 over -->

第二种：

在网站底部footer.php中添加以下代码

<script async src="https://cdn.ly522.com/js/jilei.pure.mini.js"></script> 
<span id="jilei_container_site_pv">本站总访问量<span id="jilei_value_site_pv"></span>次</span> 
<span class="post-meta-divider">|</span> 
<span id="jilei_container_site_uv">本站访客数<span id="jilei_value_site_uv"></span>人</span></p>

第三种：

以下代码添加网站页脚

<?php
@session_start();
$counter = intval(file_get_contents("counter.dat"));
if(!$_SESSION['#'])
{
$_SESSION['#'] = true;
$counter++;
$fp = fopen("counter.dat","w");
fwrite($fp, $counter);
fclose($fp);
}
?>
<p align="center">您是到访的第<?php echo "$counter";?>位用户<p>

第四种：

代码放置在 主题目录下：footer.php

<?php
//首先你要有读写文件的权限，首次访问肯不显示，正常情况刷新即可
$online_log = "maplers.dat"; //保存人数的文件到根目录,
$timeout = 30;//30秒内没动作者,认为掉线
$entries = file($online_log);
$temp = array();
for ($i=0;$i<count($entries);$i++){
$entry = explode(",",trim($entries[$i]));
if(($entry[0] != getenv('REMOTE_ADDR')) && ($entry[1] > time())) {
array_push($temp,$entry[0].",".$entry[1]."\n"); //取出其他浏览者的信息,并去掉超时者,保存进$temp

array_push($temp,getenv('REMOTE_ADDR').",".(time() + ($timeout))."\n"); //更新浏览者的时间
$maplers = count($temp); //计算在线人数
$entries = implode("",$temp);
//写入文件
$fp = fopen($online_log,"w");
flock($fp,LOCK_EX); //flock() 不能在NFS以及其他的一些网络文件系统中正常工作
fputs($fp,$entries);
flock($fp,LOCK_UN);
fclose($fp);
echo "在线人数：".$maplers."人";
?>

第五种：

直接添加网站底部合适位置即可，自动计算

<span id="runtime_span"></span>
<script type="text/javascript">function show_runtime(){window.setTimeout("show_runtime()",1000);X=new 
Date("10/16/2017 5:22:00");
Y=new Date();T=(Y.getTime()-X.getTime());M=24*60*60*1000;
a=T/M;A=Math.floor(a);b=(a-A)*24;B=Math.floor(b);c=(b-B)*60;C=Math.floor((b-B)*60);D=Math.floor((c-C)*60);
runtime_span.innerHTML="本站勉强运行: "+A+"天"+B+"小时"+C+"分"+D+"秒"}show_runtime();</script>