Question

在JavaScript中

我声明了这个var a = "p", b = "q", c = "r";

和var obj = {a : "x", b: "y", c:"z"};

我希望var obj = { "p": "x" , "q": "y", "r": "z"}

但我没有得到同样的结果。

Answer 1

<form enctype="multipart/form-data" method="POST" action=""> 
    <label>Your Profile Pic<input type="file" name="my_file" /></label>
    <label><input type="submit" name="button" value="Submit" /></label>
</form>
<?php
if($_POST && isset($_FILES['my_file'])) {

    $from_email  = 'sanjay@.com'; //from mail, it is mandatory with some hosts
    $recipient_email = 'sanjay@.com'; //recipient email (most cases it is your personal email)

    //Capture POST data from HTML form and Sanitize them, 
    //$sender_name    = filter_var($_POST["sender_name"], FILTER_SANITIZE_STRING); //sender name
   // $reply_to_email = filter_var($_POST["sender_email"], FILTER_SANITIZE_STRING); //sender email used in "reply-to" header
   // $subject        = filter_var($_POST["subject"], FILTER_SANITIZE_STRING); //get subject from HTML form
   //$message        = filter_var($_POST["message"], FILTER_SANITIZE_STRING); //message

   /* //don't forget to validate empty fields 
   if(strlen($sender_name)<1) {
       die('Name is too short or empty!');
   } 
   */

   //Get uploaded file data
   $file_tmp_name    = $_FILES['my_file']['tmp_name'];
   $file_name        = $_FILES['my_file']['name'];
   $file_size        = $_FILES['my_file']['size'];
   $file_type        = $_FILES['my_file']['type'];
   $file_error       = $_FILES['my_file']['error'];

   if($file_error > 0) {
       die('Upload error or No files uploaded');
   }
   //read from the uploaded file & base64_encode content for the mail
   $handle = fopen($file_tmp_name, "r");
   $content = fread($handle, $file_size);
   fclose($handle);
   $encoded_content = chunk_split(base64_encode($content));

   $boundary = md5("sanwebe");
   //header
   $headers = "MIME-Version: 1.0\r\n"; 
   // $headers .= "From:".$from_email."\r\n"; 
   //$headers .= "Reply-To: ".$reply_to_email."" . "\r\n";
   $headers .= "Content-Type: multipart/mixed; boundary = $boundary\r\n\r\n"; 

   //plain text 
   $body = "--$boundary\r\n";
   $body .= "Content-Type: text/plain; charset=ISO-8859-1\r\n";
   $body .= "Content-Transfer-Encoding: base64\r\n\r\n"; 
   // $body .= chunk_split(base64_encode($message)); 

   //attachment
   $body .= "--$boundary\r\n";
   $body .="Content-Type: $file_type; name=".$file_name."\r\n";
   $body .="Content-Disposition: attachment; filename=".$file_name."\r\n";
   $body .="Content-Transfer-Encoding: base64\r\n";
   $body .="X-Attachment-Id: ".rand(1000,99999)."\r\n\r\n"; 
   $body .= $encoded_content; 

   $sentMail = @mail($recipient_email, $subject, $body, $headers);
   if($sentMail) { 
       //output success or failure messages   
       die('Thank you for your email');
   } else {
       die('Could not send mail! Please check your PHP mail configuration.');  
   }
}
?>

除非你像上面那样直接指向它，否则

变量无法评估。

var obj = {};
obj[a] = "x"; // is what you want.
//Or
obj = {[a]: "x"}

Answer 2

你可以像这样使用computed property：

var obj = {[a]: "x", [b]: "y", [c]: "z"}

或者您可以使用obj[a]，因为其他人已建议使用a中的值作为密钥的名称。

注意：计算出的属性在每个环境中都不会得到支持。请参阅＆＃34;浏览器兼容性＆＃34;我在上面发布的链接部分。

Answer 3

查找

＆＃13;

var a = "p", b = "q", c = "r";
var obj = {[a] : "x", [b]: "y", [c]:"z"};

console.log(obj);

＆＃13;

Answer 4

代码

var a = "p", b = "q", c = "r";
var obj = {a : "x", b: "y", c:"z"};

function getObj(obj){
   var scope = this;
   var result = {};
   for(var key in obj){
      result[eval(key)] = obj[key];
   }
   return result;
};
var requiredObj = getObj(obj); 

//result - Object {p: "x", q: "y", r: "z"}
console.log(requiredObj);

如何获得此对象作为结果

4 个答案:

代码