CODE EXAMPLE FOR CSHARP

2d movement

var motion = Vector2()
var speed  = 150
var gravity = 30
var jump=-600
var double_jump_power = -750
var can_double_jump = false
func _ready():
	
	pass
func _physics_process(delta):
	Double_jump_and_jump()
	if Input.is_action_pressed("ui_right"):
		motion.x = speed 
		A.play("run")
		A.flip_h = false
	elif Input.is_action_pressed("ui_left"):
		motion.x = -speed
		A.play("run")
		A.flip_h = true
	else:
		motion.x = 0
	if is_on_floor()==false:
		motion.y +=  gravity
	move_and_slide(motion,Floor)
func Double_jump_and_jump():
	if is_on_floor()==true:
		can_double_jump=true
	if Input.is_action_just_pressed("ui_up")&& is_on_floor()==true:
		motion.y = jump
	#double_jump if you dont like it just remove these lines of code downhere 
	if is_on_floor() ==false && motion.y > 0 && can_double_jump==true&& Input.is_action_just_pressed("ui_up"):
		motion.y = double_jump_power
		can_double_jump=false
	pass
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