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Reference Error for property of Javascript Object

Answer 1

+3 A:

Well, yes, the variable uName isn't defined, in the snippet you posted. Neither's dQuery or execQuery, or dFeilds (spelling!). Are they coming from other code you haven't shown us?

There's a property this.uName, but object properties are a completely different thing to variables in JavaScript. Unlike Java, they don't share a namespace.

Also, you need to URL-encode parameters. eg.:

this.qUrl = "http://api.bfbcs.com/api/pc?players="+encodeURIComponent(this.uName)+"&amp;fields="+encodeURIComponent(this.dField);

bobince 2010-04-18 13:01:26

@OP: Following on from Bob's points, `this` in Javascript is *very different* from `this` in languages like C, C#, or Java. Don't let the similar name and (in some ways) similar functionality deceive you. Amongst other things, you can never leave off `this` as you can in those others, it's never assumed in Javascript.

T.J. Crowder 2010-04-18 13:07:23

@bobince,Thanks,I made the appropriate changes and made the URL changes. everything is working correctly now.

Jeremy Petzold 2010-04-18 13:42:23

Added a missing `this.` in front of `dField` in the URL.

Tim Down 2010-04-18 14:37:58

Aside: which is better etiquette? Correcting a minor error in an answer or leaving a comment pointing the error out and leave the editing to the answer author?

Tim Down 2010-04-18 14:44:50

I omitted the `this` because it wasn't clear to me that `dFeilds` in the plural was supposed to be the same as `dFeild`. You're probably right though! [meta: And for minor errors an edit is fine... I think I'd probably tend to edit more on an already-accepted answer and comment more when there's no accepted answer, but I can't wholly explain that.]

bobince 2010-04-18 15:14:47

Answer 2

+1 A:

I am not sure what you are trying to do but I dont see your function receiving those parameters:

function DataSet(uName,dFeilds,dQuery,execQuery)
{
  this.uName = "";
  this.dFeild = "";
  this.qUrl = "http://api.bfbcs.com/api/pc?players="+uName+"&amp;fields="+dFeilds;
  this.data = "";

  this.dQuery = dQuery;
  this.execQuery = execQuery;

Rajat 2010-04-18 13:03:22

In the examples I looked at on the web at the W3C they did not pass in parameters for methods like teh ones at the bottom. They did however for properties, but I saw elsewhere thatyou could forgo that.It seems a little redundant to have to specify the variable for a class then specify the property and assign the variable to that property.... but then it is OK to update that property directly through class methods, leaving the variable to only have the purpose of creating a defined memory location.Unless I could do something like this: this.uName = var uName;

Jeremy Petzold 2010-04-18 13:21:16

Declaring `var` isn't anything to do with memory locations, it is to do with specifying the block in which a variable will be local. Arguments are automatically local variables so you don't need to `var` them.

bobince 2010-04-18 15:17:14

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Reference Error for property of Javascript Object

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