def end_arr_add(arr, element) # Add element to the end of the Array variable arr and return arr arr.push(element) end

def begin_arr_add(arr, element) # Add element to the beginning of the Array variable arr and return arr arr.unshift(element) end

def index_arr_add(arr, index, element) # Add element at position index to the Array variable arr and return arr arr.insert(index, element) end

def index_arr_multiple_add(arr, index) # add any two elements to the arr at the index arr.insert(index, 'a', 'b') end

Try this