how to wait for 1 second in unity code example

Example 1: unity wait for seconds

void start() => StartCoroutine(MyIEnumerator());

IEnumerator MyIEnumerator()
{
	Debug.Log("Hello world!");
    yield return new WaitForSeconds(3);
    Debug.Log("Goodbye world!");
}

Example 2: wait for a second unity

void Start()
    {
        //Start the coroutine we define below named ExampleCoroutine.
        StartCoroutine(ExampleCoroutine());
    }

    IEnumerator ExampleCoroutine()
    {
        //Print the time of when the function is first called.
        Debug.Log("Started Coroutine at timestamp : " + Time.time);

        //yield on a new YieldInstruction that waits for 5 seconds.
        yield return new WaitForSeconds(5);

        //After we have waited 5 seconds print the time again.
        Debug.Log("Finished Coroutine at timestamp : " + Time.time);
    }