foreach (string s in sList)
{
    if (s.equals("ok"))
        return true;
}

return false;

Alternatively, if you need to do some other things after you've found the item:

bool found = false;
foreach (string s in sList)
{
    if (s.equals("ok"))
    {
        found = true;
        break; // get out of the loop
    }
}

// do stuff

return found;

I think for simple loops, such as these, the standard first syntax is much clearer. Some people consider multiple returns confusing or a code smell, but for a piece of code this small, I do not believe this is a real issue.

It gets a bit more debatable for more complex loops. If the loop's contents cannot fit on your screen and has several returns in the loop, there is an argument to be made that the multiple exit points can make the code more difficult to maintain. For example, if you had to ensure some state maintenance method ran before exiting the function, it would be easy to miss adding it to one of the return statements and you would cause a bug. If all the end conditions can be checked in a while loop, you only have one exit point and can add this code after it.

That said, with loops especially it is good to try and put as much logic as possible into separate methods. This avoids a lot of cases where the second method would have advantages. Lean loops with clearly separated logic will matter more than which of these styles you use. Also, if most of your application's code base is using one style, you should stick with that style.

There's no such thing. Just do the inverse for the content you actually want to display. So don't do

<c:forEach items="${requestScope.DetailList}" var="list">
    <c:if test="${list.someType eq 'aaa' or list.someType eq 'AAA'}">
        <<<continue>>>
    </c:if>
    <p>someType is not aaa or AAA</p>
</c:forEach>

but rather do

<c:forEach items="${requestScope.DetailList}" var="list">
    <c:if test="${not (list.someType eq 'aaa' or list.someType eq 'AAA')}">
        <p>someType is not aaa or AAA</p>
    </c:if>
</c:forEach>

or

<c:forEach items="${requestScope.DetailList}" var="list">
    <c:if test="${list.someType ne 'aaa' and list.someType ne 'AAA'}">
        <p>someType is not aaa or AAA</p>
    </c:if>
</c:forEach>

Please note that I fixed an EL syntax error in your code as well.

You can use std::any_of (or std::all_of or std::none_of) e.g. like this:

std::vector<int> a;
// ...     
std::all_of(a.begin(), a.end(), & { 
  // return false if you want to break, true otherwise
  });

However, this is a wasteful solution (return values are not really used for anything), and you're better off writing you own loop.