Lua passing multi dimensional array

Question

Hi I am a fairly new Lua programmer and I am trying to pass parameters to a multidimensional array, but I keep getting a nil value error.

I have a multidimensional array:

local transform = {
  forward = {
    distance = 1,
    swing = robot.swing,
    move = robot.forward
  },
  left = {
    distance = 1,
    swing = robot.swing,
    move = robot.forward
  },
  down = {
    distance = 1,
    swing = robot.swingDown,
    move = robot.down
  }
}

and I am trying to pass parts of the array like so:

function testFunc(transform, direction)
  print(transform.direction.distance)
end

myFunc(transform, forward)

Those are tables, not arrays. OK, in Lua arrays are tables, but they're not array-like tables. They're just key-value tables. — Nicol Bolas
– Nicol Bolas, Commented Aug 1, 2017 at 22:33

Sophie Swett · Accepted Answer · 2017-08-01 22:35:13Z

1

The expression transform.direction looks up the value in transform whose key is the word "direction". If you want the value whose key is the value of the direction variable, use transform[direction] instead:

function testFunc(transform, direction)
  print(transform[direction].distance)
end

answered Aug 1, 2017 at 22:35

Sophie Swett

3,4481 gold badge28 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Evan Martinez Over a year ago

Thank you! That answered my question

Collectives™ on Stack Overflow

Lua passing multi dimensional array

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related