How to use buttons to change pictures in the UIImageView that are in my assets?

Can you explain precisely what you want ? The title is not made to formulate the full question.

Do you know how to set imageView ?

In the button IBAction, just add the following

        myimageView.image = UIImage(named: "SomeImage")

Use Tag Value To Change your image View, Based On Tag U Can image View images without any another variable. I only told to change only

3 images in between them if u want more than u have to maintain tags.

@IBOutlet func changeImageBtnTouchUpInside(_ sender:UIButton){

if(sender.tag == 0){

myimageView.image = UIImage(named: "firstImage")

sender.tag = 1

}else if(sender.tag == 1){

myimageView.image = UIImage(named: "secondImage")

sender.tag = 2

}else if(sender.tag == 2){

myimageView.image = UIImage(named: "thirdImage")

sender.tag = 0

}

}