Passing object array - Unexpected token [

Question

function showConfirm(reArray) {

    var theHTML = '';
    var optionArray = ["Option 1", "Option 2", "Option 3", "Option 4", "Option 5", "Option 6", "Option 7"]; 
    var myButtons = {};
    var j = 1;

    for(var i = 0; i < reArray.length; i++){

                theHTML  +='<div style="text-align:center">' 
                         + '<span>'+j+'.</span>&nbsp;&nbsp;&nbsp;&nbsp;'
                         + '<span>'+reArray[i].RoadNo+'</span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'
                         + '<span>'+compass_image(reArray[i].Bearing)+'</span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'
                         + '</div><br/>'    

                j++;
        }

    for(i = 0; i < reArray.length; i++){

    ERROR HERE -----> var placeFunction = function(reArray[i]){

                                plotRoadInfo(reArray[i]);
                                $(this).dialog("close");
                            };

                            myButtons[optionArray[i]] = placeFunction;
    }

    $( "#dialog-modal" ).dialog({
      height: 300,
      modal: true,
      buttons: myButtons

    });

    $('#multipleRE').append(theHTML);
}

So the function gets passed an object array (reArray), it then creates an array of buttons (myButtons) for a jquery dialog box. I'm attempting to to pass reArray[i] to the function that will be used by each button, which is to execute plotRoadInfo(reArray[i]);

I keep getting "Unexpected token [", and I can't figure out why for the life of me.

You're `function` clause is a function instantiation. It doesn't make sense for a formal parameter to have an index expression like that. — Pointy, Apr 15 '13 at 01:34

score 3 · Accepted Answer · edited May 23 '17 at 12:18

3

You don't specify the type of a parameter in JavaScript, simply use the name and then use it as an array in your function.

var placeFunction = function(reArray){
    plotRoadInfo(reArray[i]);
    $(this).dialog("close");
};

I don't think you even need to specify it though as you're referring to as array that the inner function has access to.

var placeFunction = function() {
    plotRoadInfo(reArray[i]);
    $(this).dialog("close");
};

As Pointy notes this will run in to issues with the i variable being shared so each function will refer to reArray[reArray.length] because the loop will complete when i === reArray.length. A common way to get around this is to call a function that accepts i as a parameter that will return a function.

var placeFunction = (function (item) {
    return function() {
        plotRoadInfo(item);
        $(this).dialog("close");
    };
}(reArray[i]));

Read up on closures for a deeper understanding of how this works. Here is another example of this happening.

edited May 23 '17 at 12:18

Community

1
1

answered Apr 15 '13 at 01:34

Daniel Imms

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This probably won't work, however, because "i" in the external context is **shared** among all the "placeFunction" instances. – Pointy Apr 15 '13 at 01:37
Thanks for the quick response. I'll try your first suggestion now. I've tried the second suggestion (no specification) and none of the objects properties were passing to plotRoadInfo(). Lemme get on the other option now and I'll get back to you. – Matthew Paxman Apr 15 '13 at 01:38
Ok so, @DanielImms, passing function(reArray) gets rid of the error, but none of the object properties pass. For example, in plotRoadInfo();: `reArray.Lat` now comes up with the error `Cannot read property 'Lat' of undefined`. – Matthew Paxman Apr 15 '13 at 01:40
I updated my answer, it's `undefined` because its referring to `reArray[reArray.length]`. – Daniel Imms Apr 15 '13 at 01:41
Should I just pass `plotRoadInfo(reArray)` instead of passing [i], or do I still need to specify that I'm passing the [i]th object? – Matthew Paxman Apr 15 '13 at 01:43
You can do it a few ways, passing the object `reArray[i]` is probably the nicest. – Daniel Imms Apr 15 '13 at 01:44

score 2 · Answer 2 · answered Apr 15 '13 at 01:38

The syntax you have is incorrect.

I believe what you want to do is the following:

var placeFunction = 
    (function(arrayitem){
        return function(){
                   plotRoadInfo(arrayitem);
                   $(this).dialog("close");
               };

     })(reArray[i]);

myButtons[optionArray[i]] = placeFunction;

score 1 · Answer 3 · answered Apr 15 '13 at 01:33

1

Why does the parameter have an index?

function(reArray[i])

did you mean

function(reArray)

answered Apr 15 '13 at 01:33

Joseph

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Passing object array - Unexpected token [

3 Answers3