Chained Arrow function syntax

Question

const fetch = url => dispatch => {
  // ...
}

export const fetchQuestions = tag => (dispatch) => {
  return dispatch(fetch(tag));
};

What

Answer 1

This is equivalent to one function returning another. I.e. this

const fetch = url => dispatch => {
    // ...
}

is equivalent to

const fetch = function(url) {
    return function(dispatch) {
        // ... 
    }
}

---

Similarly this

export const fetchQuestions = tag => (dispatch) => {
  return dispatch(fetch(tag));
};

is equivalent to

export const fetchQuestions = function(tag) {
    return function(dispatch) {
        return dispatch(fetch(tag));
    }
};