How to select an animation clip by index number?

I know this question is old, but I thought I'd share my fix.

I had 80 animated characters all with the same 5 animations, though some of them were named differently because it would be the walk cycle for a crawling baby or an old man with a walking stick, therefore different from the walk cycle of my generic humans.

What I did was create a script that just had a variable for animationClips.

 var animList : AnimationClip[];

That's it, that's all my script had lol. Then I applied it to the prefabs of all my 80 chars, and listed their animations in respective order:

bind walk flinch dance suicide

Then in script I just said

 gameObject.animation.Play(getComponent(AnimList).animList[0]);

basically I couldn't access THEIR array so I made my own array that I COULD access.

I believe you can't, stupid, isn't it? You CAN however iterate over the animationclips with the (in C#) foreach keyword:

foreach (AnimationClip clip in animation) {
    // do initialisation or something on clip
}

Kind of simple, but if it saves someone some time...

 string ClipIndexToName(int index)
 {
     AnimationClip clip = GetClipByIndex(index);
     if (clip == null)
         return null;
     return clip.name;
 }

 AnimationClip GetClipByIndex(int index)
 {
     int i = 0;
     foreach (AnimationState animationState in animation)
     {
         if (i == index)
             return animationState.clip;
         i++;
     }
     return null;
 }

Update, since the above seems to have broke with Unity 5 (or maybe was always fragile and now I'm just finding out), I ended up changing GetClipByIndex to this. Too bad I have to hard-code the clip names, a little extra work:

 AnimationClip GetClipByIndex(int index)
 {
     string[] ClipNames = { "StepForward", "StepBackward", "ShortThrow", "LongThrow", "BackwardThrow", "SoftThrow", "Bull", "Hurt" };
     Animation animation = GetComponent<Animation>();
     return animation[ClipNames[index]].clip;
 }

Not sure if this is how it's supposed to work, but this does exactly what your asking.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class EnemyMovement : MonoBehaviour {
 
     Animation anim;
     public List<string> animNames;
 
     void Start(){
         
         anim = GetComponent<Animation> ();
 
         foreach (AnimationState clip in anim) {
             animNames.Add(clip.name.ToString());
         }
     }
 
     void Update(){
 
         if (//something happens//) {
             anim.CrossFade (animNames [1]);             //plays animation in element1 spot
         } else {
             anim.CrossFade (animNames [0]);             //plays animation in element0 spot
         }
     }
 }
 

Animations in Array: Someone has tried to make a unique class to attach to the gameobject you're animating. I can't get it to work, but I understand the idea ..... I think. Anyway here is the thread: http://forum.unity3d.com/threads/64262-Animation-clips-in-array-!!?highlight=animation+clip+index