Object.byString

Object.byString.js

// Usage: Object.byString(someObj, 'part3[0].name');
// Demo: http://jsfiddle.net/alnitak/hEsys/
 
Object.byString = function(o, s) {
    s = s.replace(/\[(\w+)\]/g, '.$1'); // convert indexes to properties
    s = s.replace(/^\./, '');           // strip a leading dot
    var a = s.split('.');
    for (var i = 0, n = a.length; i < n; ++i) {
        var n = a[i];
        if (n in o) {
            o = o[n];
        } else {
            return;
        }
    }
    return o;
}