check if a item in list, exists in another list with linq

i’m new in c# ,sorry for bad question.

how can i say, if an item in a list,

exists in another list?

l know it can be done using linq functions, but I don’t know which method can help.

I want something like this:

bool Exists(List<int> list1, List<int> list2)

{
    // if the value of the first index of list1 exists in list2, return true.

}

>Solution :

well

you can do this

bool Exists(List<int> list1, List<int> list2)
{
var firstIndex=list1.First();

return list2.Any(num=> num == firstIndex);
}