# What's wrong with my animation trigger script?

So I am making an RPG and I am setting up the player. I am trying to trigger an attack animation by pressing a button. I wrote this down and I get an error that says "Expressions in statements must only be executed for their side-effects". I don't know what that means, but it is an error that won't let me play the game without fixing it. I'm not sure where to go from here. How would I fix the error? EDIT: I'm not using Mecanim, nor am I planning on using it.

This is the script. It is in JavaScript (Unity3D).

#pragma strict

var anim: AnimationClip;

function Start()
{
animation["Sword Slash"].layer = 4;
animation["Sword Slash"].wrapMode.Once;
}

function Update ()
{

if (Input.GetKeyDown ("c"))
{
animation.Play("Sword Slash");
}
}

• Playing animation clip that way is not usual anymore. Unity has mecanim now to control animations and keep it in a structured way. I suggest you to use mecanim. Go to : docs.unity3d.com/Manual/AnimationOverview.html It's fun. – Sourav Paul Jun 19 '16 at 18:00
• It doesn't look like the code you've shown contains anything that would trigger the error message you describe. Usually it happens from forgetting the parentheses in a function call or things like that. Did the error message tell you the file & line number where the error occurred? You can usually double-click the message to jump precisely to the problem spot. – DMGregory Jun 20 '16 at 2:35
• DMGregory: I did, and it brings me to line 7 (animation["Sword Slash"].wrapMode.Once;) – user80678 Jun 20 '16 at 5:34

The line animation["Sword Slash"].wrapMode.Once doesn't actually do anything, and that's why an error is generated, to help you. Maybe you meant to assign by calling animation["Sword Slash"].wrapMode = WrapMode.Once?