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1

I am trying to add values into an array but for some reason it is not working. I am new to JavaScript.

Here is my code:

eventsArray = new Array();

$.each(xmlJsonObj.feed.entry, function(index, value){
    eventsArray[index] = new Array('title' = value.title, 'date' = value.date[1]);
});

So basically I am pulling out some values from the json object and want to save them as key-value pairs in an array (multidimensional as each event has several values).

This array will later be sorted by date.

I am currently getting the following error:

ReferenceError: Left side of assignment is not a reference.

I am new to JavaScript and don't really understand whats wrong. Tried to look at some examples but still can't see a good example of creating two dimensional arrays with JavaScript (or objects, as everything in JS is an object) in a loop like this.

I would be very thankfull for any help or tips.

share|improve this question
up vote 4 down vote accepted

The cause of the error message is this:

'title' = value.title

That would mean that you are trying to assign a value to a literal string. The rest of the code (except from the other one just like it) is actually valid syntax, even if that is not what you are trying to do, so that's why you get the error message on that part of the code.

To have a collection of key-value pairs you would use an object instead of an array, and you can create it like this:

eventsArray[index] = { title: value.title, date: value.date[1] };
share|improve this answer
    
Accepted aaaanswer!!! ;) Was looking for the first assignment to spot the error, did miss the second new array(), thanks. ;) – loveNoHate Jan 30 '14 at 13:05
    
+1 for RCA..... – Dipak Ingole Jan 30 '14 at 13:23
    
So do I still need to declare the array? Or is it ok not to declare it manually in JS? – Saint Dave Jan 30 '14 at 13:30
    
@alwaysStuck: You still need to create the array object before you can put anything in it. Also, although you don't need to declare variables in Javascript, it's a good practice to always do that. – Guffa Jan 30 '14 at 14:29
up vote 1 down vote

It works if you change your code to:

var eventsArray = new Array();

$.each(xmlJsonObj.feed.entry, function(index, value){
    eventsArray.push({ title : value.title, date: value.date[1] });
});
share|improve this answer
up vote 1 down vote

You should use objects for this:

eventsArray[index] = {};
eventsArray[index].title = value.title;
eventsArray[index].date = value.date[1];

The problem you have is that you try to assign value.title value to String. Arrays in JS didn't work in that way. Also Arrays didn't support String keys, this is why you may need Object.

If your date property is TIMESTAMP for example you can sort it like:

eventsArray.sort( function( a, b ) {
    return a.date - b.date;
});
share|improve this answer
    
but can I sort it? Its very important for me to be able to later sort it according to the date value and display them in order according to date. Is this possible with objects? I know its possible with arrays. – Saint Dave Jan 30 '14 at 12:50
1  
@alwaysStuck yes, look at my updated answer – antyrat Jan 30 '14 at 12:56
    
Thanks! This is great! – Saint Dave Jan 30 '14 at 13:23
up vote 1 down vote

May be simplest one,

var eventsArray = new Array();

$.each(xmlJsonObj.feed.entry, function (index, value) {
    eventsArray[index] =  { 'title': value.title, 'date': value.date[1] };
});
share|improve this answer
    
@Guffa I am assuming eventsArray is an array declared above .each loop – Dipak Ingole Jan 30 '14 at 12:59

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