Question

First of all, I converted a Plist(XML formatted) to JSON with some online tool, this isn’t the problem. I managed to pick the important values from this rather big JSON file. With this important information I am rebuilding a new JSON file that is very lean and contains information I can use for a plug-in — that I will create later.

The plist conversion to JSON is ugly. At some point <true/> and <false/> are converted to JSON, leaving this in the JSON: "false":"", or "true":"",.

I am using jQuery

check JSfiddle for an example jsfiddle example

or here

// Simplified (not really a JSON file, but this will do it for explaining) 
var themeJSON = {
    "item": {
        "false": "",
    },
};

// I need to know if its enabled: "true" or disabled: "false"

// function for checking if this is the default option
function checkDefault() {
    // true is a keyword!
    if (themeJSON.item.true) {
        return "1";
    // so is false!
    } else(themeJSON.item.false) {
        return "0";
    }
}

Maybe I use some other function such as find() ?

updated for answer:
thanks to the comments, this is what I have now:

function checkDefault() {
    if (item.hasOwnProperty("true")) {
        return "1";
    } else if(item.hasOwnProperty("false")) {
        return "0";
    }
}

Answer 1

When an object property has a name which is a reserved keyword, the array index notation can be used to reference it.

A way of checking whether item has a property named false:

> themeJSON.item.hasOwnProperty("false");
true

This not ideal because a single object could have both a false property and a true property.