How can we call one controller function from another controller function in Lightning in Salesforce ?

Hii Kirandeep,

I think that the better approach would be to try to extract whatever it is that you need to call in that controller function into the helper and call the helper. The helpers exist to enable sharing code within a component. Do you have a use case where that wouldn't work?

Just for fun, inspecting the action object the following would work:

var action = component.get("c.bar");
action.$meth$();