php 字符串和数字比较一些问题

//示例1
<?php
$a = '511203199106034578';
$b = '511203199106034579';
if ($a==$b) {
echo 'equal';
} else {
echo 'notEqual';
}
?>

//示例2
<?php
$a = 'a511203199106034578';
$b = 'a511203199106034579';
if ($a==$b) {
echo 'equal';
} else {
echo 'notEqual';
}
?>

<?php
$a = 511203199106034578;
$b = 511203199106034579;
echo $a; // 输出 5.1120319910603E+17 即511203199106030000
echo $b; // 输出 5.1120319910603E+17 即511203199106030000
?>

//示例4
<?php
$a = '511203199106034578';
$b = '511203199106034579';
if ($a===$b) {
echo 'equal';
} else {
echo 'notEqual';
}
?>

function getValue(url, name) {
 var reg = new RegExp('(\?|&)' + name + '=([^&?]*)', 'i');
 var arr = url.match(reg);

 if (arr) {
  return arr[2];
 }

 return null;
}

function getKeyValue(url) {
 var result = {};
 var reg = new RegExp('([\?|&])(.+?)=([^&?]*)', 'ig');
 var arr = reg.exec(url);

 while (arr) {
  result[arr[2]] = arr[3];

  arr = reg.exec(url);
 }

 return result;
}

function getKeyValue($url) {
 $result = array();
 $mr = preg_match_all('/(?|&)(.+?)=([^&?]*)/i', $url, $matchs);

 if ($mr !== FALSE) {
  for ($i = 0; $i < $mr; $i++) {
   $result[$matchs[2][$i]] = $matchs[3][$i];
  }
 }

 return $result;
}

<?php
  $file=iconv("utf-8","gb2312",$_POST['files']);           //实现编码格式的转换
  if(file_exists($file)){                                  //判断文件是否存在
          $change_time=filectime($file);                   //获取文件的最后incode时间
          $time=date("Y-m-d h:i:s",$change_time);          //时间戳的格式化
          $last_time=filemtime($file);                     //获取文件的最后修改时间
          $times=date("Y-m-d h:i:s",$last_time);           //时间戳的格式化
   }else{
          $result="该文件不存在";
   }
   ?>

function check($var){//验证数组的返回值是否为空
          return($var!="");
  }

  <table width="750"border="0"cellspacing="0"cellpadding="0">
        <form action="index_ok.html"method="post"enctype="multipart/form-data"name="form1">
           <tr>
             <td width="100"height="25"align="right"class="STYLE1">内容1：</td>
             <td width="150"align="center"><input name="files[]"type="text"id="files[]"size="15"></td>
             <td align="left"><input name="picture[]"type="file"id="pcture[]"size>="30"></td>
           </tr>
           <tr>
             <td height="25"align="right"class="STYLE1">内容2：</td>
             <td width="center"><input name="files[]"type="text"id="files[]"size="15"></td>
             <td align="left"><input name="picture[]"type="file"id="pcture[]"size>="30"></td>
           </tr>
         <tr>
            <td colspan="3"align="center">
                 <input type="image"name="imageField"src="images/bg_09.jpg">&nbsp;&nbsp;&nbsp;&nbsp;
                 <input type="image"name="imgeField2"src="images/bg_11.jpg"></td>
            </tr>
          </form>
         </table>

<?php
    header("Content-type:text/html;charset=UTF-8");     //设置文件编码格式
    include"conn/conn.php";                             //包含数据库链接文件
    if($_POST[files]!=""){
          if(! is_dir("./upfile")){
                  mkdir("./upfile");                    //创建上传文件存储文件夹
          }
          $data=date("Y-m-d H:m:s");                    //定义时间
          function check($var){                         //验证数组的返回值是否为空
                     return($var!="");                  //如果不为空则返回数组元素
          }
          $files=array_filter($_POST["files"],"check");  //去除数组中空值
          $array=array_filter($_FILES["picture"]["name"],"check"); //去除数组中空值
          foreach=($aarray as $key=>value){             //循环读取数组中数据
                 $path='upfile/'.time().$key.strtolower(strstr($value,".")); //定义上传文件存储位置
                 move_uploaded_file($_FILES["picture"]["tmp_name"][$key],$path);  //执行上传操作
                 $query="insert into tb_up_file(file_test,data,file_name)values('$path','$data''$files[$key]')";
                 $result=mysql_query($query);
          }
          echo"<script>
          alert('图片上传成功');window.location.href='index.html';</script>";
         }
         ?>

<?php
$zip = new ZipArchive;
if ($zip->open('test.zip') === TRUE) {
 for($i = 0; $i < $zip->numFiles; $i++)
   {
     if(substr_count($zip->getNameIndex($i), 'example.php')>0){
       $contents = $zip->getFromIndex($i);            
      }
   }
}
?>