
Ask HN: Examples of very basic concepts worth internalizing? - pixelperfect
I often see people have to think for 7+ seconds to answer this sort of question:<p>How many integers are in the range [2, 10]?<p>How many integers are in the range (3, 18)?<p>How many integers are in the range [4, 9)?<p>In my opinion, it&#x27;s worthwhile for any programmer to internalize this to the point they don&#x27;t have to think. Just know this:<p>- The number of integers in an inclusive range is 1 more than the difference<p>- The number of integers in an exclusive range is 1 less than the difference<p>- The number of integers in a range inclusive on one side is the difference.<p>Are there any other examples of very basic concepts worth internalizing that some people seem to miss?
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dmuth
Powers of 2 is a big one for me.

