If the key is absent, how many comparisons does linear search make?

1. The search cannot conclude absence until the list is exhausted. 2. Every element has to be tested. 3. If the key is not present, linear search has to make n comparisons. 4. That is the same as the worst successful case. _Source: syllabus Computer Science, Ch 5 'Sorting' and Ch 6 'Searching'_