These can help you keep track of which state your character is in. Is the character attacking, walking or idle? That sort of thing. You could go further and create a state machine for more complex character states and player interactions, but for a simple game it is sufficient to track the states like in the example.
I’d probably take it on step further and move the states to constants:
local STATE_SWORD_ATTACK = hash("attack_sword")
local STATE_WALKING = hash("walking")
local STATE_IDLE = hash("idle")
function on_input(self, action_id, action)
if action_id == hash("sword") then
self.state = STATE_SWORD_ATTACK
...
...
self.state = STATE_WALKING -- or STATE_IDLE
The advantage is that there is less risk of typos, especially if you use a code linter/language server.