What is this function in Bootcamp demo?

Unity Engine
1

in Footsteps.js,

 function GetAudio() : AudioClip
 {
  var hit : RaycastHit;
   if(Physics.Raycast(t.position + new Vector3(0, 0.5, 0), -Vector3.up, hit, Mathf.Infinity, hitLayer))
  {
   cTag = hit.collider.tag.ToLower();
  }

What is that ToLower() ?
Where can I find this function and what it does, how it works?
Thanks

2

ToLower() is a simple function which returns a copy of a string, where all the characters are lowercase.

For example:

var myString = "HelLo WorlD!";
var myLowerCaseString = myString.ToLower(); //myLowerCaseString = "hello world!"
3

ah. It is… Thanks.