Coroutines and Yield - Unity 3 Game Development - page 325

StartCoroutine
Starts a corouine.
The execuion of a corouine can be paused at any point using the yield statement. The
yield return value speciies when the corouine is resumed. Corouines are excellent when
modeling behavior over several frames. Corouines have virtually no performance overhead.
StartCoroutine funcion always returns immediately, however you can yield the result.
This will wait unil the corouine has inished execuion.
When using JavaScript it is not necessary to use StartCoroutine ,
as the compiler will do this for you. When wriing C# code you must
call StartCoroutine . (For more details, refer to Appendix C ,
Major differences Between C# and Unity JavaScript. )
In the following example, we show how to invoke a coroutine and coninue execuing the
funcion in parallel:
function Start() {
// Starting = 0.0
Debug.Log ("Starting = " + Time.time);
// StartCoroutine WaitAndPrint (In JavaScript, you can also use
WaitAndPrint(5.0) which will get the same result.
StartCoroutine(WaitAndPrint(5.0));
// Before WaitAndPrint = 5.0
Debug.Log ("Before WaitAndPrint = " + Time.time);
}
function WaitAndPrint(waitTime : float) {
//Suspend execution for 5 seconds
yield WaitForSeconds(waitTime);
// WaitAndPrint = 5.0
Debug.Log ("WaitAndPrint = " + Time.time);
}