I figured out how to use animations, and moving, but how can it switch to idle when doing nothing?

Question

extends KinematicBody2D

export(int) var speed = 80.0

onready var animationplayer = $AnimationPlayer

func process(delta):
if Input.isactionpressed("uileft"):
_animationplayer.play("walkleft")
else:
animationplayer.stop()

func physicsprocess(delta):
var velocity = Vector2.ZERO
if Input.isactionpressed("uiright"):
velocity.x += 1.0
if Input.isactionpressed("uileft"):
velocity.x -= 1.0
if Input.isactionpressed("uidown"):
velocity.y += 1.0
if Input.isactionpressed("uiup"):
velocity.y -= 1.0

move_and_slide(velocity * speed)

Answer 1

You could check whether the velocity is zero and then start the idle animation.