PHP中未識別的變量

Question

我正在嘗試使用此處提供的php api：https://forums.digitalpoint.com/threads/uk-post-code-distance-calculator-using-php-mysql-3-super-easy-steps.1823109/。代碼中存在一些問題，我不得不解決，但我不知道爲什麼我得到這個錯誤。

這是config.php文件：

 <?php 
     include('/config.php'); 
     /* 
     * Created on May 20, 2010 
     * 
     * Programmed by Manoj Kumar 
     */ 

     //Connect To Database 
     $host_sql = $host; 
     $username_sql = $username; 
     $password_sql = $password; 
     $dbname_sql = $dbname; 


     $con = mysqli_connect($host_sql, $username_sql, $password_sql, $dbname_sql); 

     ?> 

，這是distCalc.php文件

 <?php 
     /* 
     * Created on Jun 1, 2010 
     * 
     * To change the template for this generated file go to 
     * Window - Preferences - PHPeclipse - PHP - Code Templates 
     */ 

     include('/api/postcodedistance/config.php'); 


     //distCalc("NW4 4TE","ZE3 8HB"); 

     function distCalc($pc1_full,$pc2_full) { 


     #Convert the post code to upper case and trim the variable 
     $pc1_full = strtoupper(trim($pc1_full)); 

     #Remove any spaces 
     $pc1_full = str_replace(" ","",$pc1_full); 

     #Trim the last 3 characters off the end 
     $pc1 = substr($pc1_full,0,strlen($pc1_full)-3); 

     #Convert the post code to upper case and trim the variable 
     $pc2_full = strtoupper(trim($pc2_full)); 

     #Remove any spaces 
     $pc2_full = str_replace(" ","",$pc2_full); 

     #Trim the last 3 characters off the end 
     $pc2 = substr($pc2_full,0,strlen($pc2_full)-3); 



     $sql="SELECT * FROM `hwz_postcodes` WHERE `outcode` = '$pc1'"; 
     $result=mysqli_query($con, $sql); 
     $row=mysqli_fetch_array($result); 

     $pc1_lat=$row['latitude']; 
     $pc1_long=$row['longitude']; 


     $sql="SELECT * FROM `hwz_postcodes` WHERE `outcode` = '$pc2'"; 
     $result=mysqli_query($con, $sql); 
     $row=mysqli_fetch_array($result); 

     $pc2_lat=$row['latitude']; 
     $pc2_long=$row['longitude']; 

     //echo "<br/>".$pc1."<br/> ".$pc1_lat."<br/> ".$pc1_long; 
     //echo "<br/>".$pc2."<br/> ".$pc2_lat."<br/> ".$pc2_long; 

     $distance = getDistance($pc1_lat, $pc1_long, $pc2_lat, $pc2_long); 

     //echo "<br/>Distance:".$distance; 

     return $distance; 

     } 


     function getDistance($lat1, $long1, $lat2, $long2){ 

     #$earth = 6371; #km change accordingly 
     $earth = 3960; #miles 

     #Point 1 cords 
     $lat1 = deg2rad($lat1); 
     $long1= deg2rad($long1); 

     #Point 2 cords 
     $lat2 = deg2rad($lat2); 
     $long2= deg2rad($long2); 

     #Haversine Formula 
     $dlong=$long2-$long1; 
     $dlat=$lat2-$lat1; 

     $sinlat=sin($dlat/2); 
     $sinlong=sin($dlong/2); 

     $a=($sinlat*$sinlat)+cos($lat1)*cos($lat2)*($sinlong*$sinlong); 

     $c=2*asin(min(1,sqrt($a))); 

     $d=round($earth*$c); 

     return $d; 

     } 


     ?> 

這是我收到的錯誤：

Notice: Undefined variable: con in C:\Users\Kabeer\Dropbox\Projects\project\api\postcodedistance\distCalc.php on line 38 

精讀被定義，所以我很困惑問題是什麼。如果我使con con全球，然後我得到一個解析錯誤。我不喜歡這樣寫道：

global $con = mysqli_connect($host_sql, $username_sql, $password_sql, $dbname_sql); 

非常感謝

卡比爾

Answer 1

添加全局關鍵字在函數太：

function distCalc($pc1_full,$pc2_full) { 
    global $con; 
    //... 
} 

而且之前打個電話創建連接還：

global $con; 
$con = mysqli_connect($host_sql, $username_sql, $password_sql, $dbname_sql); 

Answer 2

只需在您的功能中放入global $con即可。