how to check gameobject layer code example

Example 1: unity get layer of gameobject

// This will retrun the layer mask of the specified gameObject
gameObject.layer

// You can as well modify this value through code
gameObject.layer = LayerMask.NameToLayer("SomeOtherLayer")

Example 2: unity check collider layer

function OnCollisionEnter(collision : Collision)
 {
     if (collision.collider.gameObject.layer == LayerMask.NameToLayer("LAYER_NAME"))
     {
          Debug.Log("Touched a rail");
     }
 }