JS委托/擴展aleady現有功能

Question

如何向功能添加代碼以保留其舊功能

SomeFunction = function () {
    someOtherFunction();
    return this.apply(this, arguments);
};

Answer 1

就這樣

var delegate = functionToBeDelegated;
functionToBeDelegated = function () {

    //
    // Add functionality to the function
    //

    // run the old version of the function in native scope
    return delegate.apply(this, arguments);
};