how to change the picture of an object on unity code example

Example 1: how to change a image with code unity

// Change From GameOject
public GameObject GameObjectWithImage;
public Sprite ImageYouWant;
GameObjectWithImage.GetComponent<Image>().sprite = ImageYouWant

// Change From Image
public Image Image;
public Sprite ImageYouWant;
Image.sprite = ImageYouWant

Example 2: unity change the source image or image

public Image test;
public Sprite example;

void Start()
{
 test.sprite = example; //change the source image of the image "test" to the sprite "example" 
}