Is it hard to get a virus on your iPhone?

My mate uses online banking on his iPhone so he was just wondering how "secure" he is using it. He only watches anime on his phone and twitch streams that's it, he used to use different anime sites but now he sticks to 1. Is it possible he could have gained a virus simply from visiting a site, or is it very hard to get a virus on iPhone?

It is nigh impossible.

https://www.apple.com/..._Guide.pdf

He can but it's unlikely. To be safer, use lookout, make sure you're using https, and make sure you're using either safari or chrome. You can also use a vpn (paid) (optional)