Why do c++ programmers use != instead of <

Question

In c++ primer, pg 95 the author says that c++ programmers tend to use != in preference of < when writing loops.

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Answer 1

It's a habit for generic programming; for example, you can easiely use < with indices, but you cannot use that with all iterator types. A list iterator cannot efficiently implement < - however, != can be implemented for even the simplest of iterator types. Therefore, it is a good habit to always use the most generic comparison - it makes your code more resilient to change.