Recursive/deep extend/assign in Underscore.js?

Question

Is there any way to get Underscore.js extend function:

Copy all of the properties in the source objects over to the destination object, and return t

Answer 1

No, Underscore will not contain a deep extend since it's too complicated to deal with different types of objects. Instead, users are encouraged to implement their own solutions with the support for what they need.

In your case it's only plain objects, so an implementation is quite straightforward:

_.deepObjectExtend = function(target, source) {
    for (var prop in source)
        if (prop in target)
            _.deepObjectExtend(target[prop], source[prop]);
        else
            target[prop] = source[prop];
    return target;
}