You're writing code to control your town's traffic lights. You need a function to handle each change from
green
, to yellow
, to red
, and then to green
again.
Complete the function that takes a string as an argument representing the current state of the light and returns a string representing the state the light should change to.
For example, when the input is green
, output should be yellow
.
def update_light(current)
{'green' => 'yellow',
'yellow' => 'red',
'red' => 'green'}[current]
end