Single Most Efficient Way to Clear Keyboard Buffer C++

Posted on 2014-02-22
Medium Priority
Last Modified: 2014-02-24
Hi All,

Can someone please tell me the single most efficient way to clear the keyboard buffer in C++?  I found the following but don't know if it's efficient:

cin.ignore(numeric_limits<streamsize>::max(), '\n');

Some background:  I'm a college student in 1st Semester OOP.

- Thanks
Question by:realchick
LVL 86

Accepted Solution

jkr earned 2000 total points
ID: 39879872
That's indeed the most portable way to do that, it just looks a bit complicated, while it isn't complicated at all. E.g. 'numeric_limits<streamsize>::max()' evaluates to a single value. Plus, it is way more efficiant to run a loop until 'cin()' is empty. So, apart from some specialities for some compilers/frameworks (e.g. MS compilers would allow a 'rewind(stdin);' for that), it is probably the most efficiant and simple way.

Author Closing Comment

ID: 39881966
Good, I'm going to post this to my classroom discussion.  Out textbook doesn't mention "numeric_limits" or even cin.clear()...so I struggled to find a good input validation solution online and my while loop just ran for miles and miles!

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