Understanding `dropWhile`

Question

In examples I've observed dropWhile's behavior:

*Main> dropWhile (/= 'X') "AXF"
"XF"

But, I'm confused why "AX" does not return:

*Main> dropWhile (== 'X') "AXF"
"AXF"

Why does "AXF" return in this test?

Answer 1

dropWhile drops elements while the condition is true and then stops (returning the remaining elements) once the condition is false.

With dropWhile (== 'X') "AXF" the condition is false right away (because 'A' == 'X' is false), so it doesn't drop anything and returns the whole list.