The examples in this gist will let you look up a property in a nested JavaScript object using a dot-delimited object path. A string like `foo.bar.baz` can be used to look up the value of `baz` in an object where baz is nested inside of bar which is nested inside of foo.

lookup.js

var lookup = function(dotPath,sourceObj){
 
    var parts       = dotPath.split('.');
    var lastPart    = parts.pop();
    var len         = parts.length;
    var counter     = 1;
    var current     = parts[0];
 
    while ((sourceObj = sourceObj[current]) && counter < len){
        current     = parts[counter];
        counter    += 1;
    }
 
    if (sourceObj){
        return sourceObj[lastPart];
    }
};

/*----------- Usage examples -----------*/

var obj = {
    foo : {
        bar : {
            baz : 'SUCCESS!',
            biz : ['first','second','third']
        }
    }
};

lookup('foo.bar.baz',obj); // Outputs "SUCCESS!"

/* Also works with nested arrays */
lookup('foo.bar.biz.1',obj); // Outputs "second"