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    <p>There are several problems here. The first, and most important, is that most systems will do line oriented input, which means that they will pick up a lot of control characters (including, probably, ESC) and do something with them internally, rather than returning them to you; it might not even be possible to ever see an ESC in the input. </p> <p>For the rest, there are several problems with your code. The first is that you're testing against the index into the array (where you'll put the next character), not against anything you've read. The second is that you're inputting <code>int</code>, so you won't see any individual characters; just the results of the conversion of your input. (In fact, if an ESC character does get through, you'll end up with <code>std::cin</code> in a error state.) The third is that you never test whether the input has succeeded.</p> <p>A better solution would be to adopt some other convention for the input: say one number per line, with an empty line signaling the end. In that case, you could write something like:</p> <pre><code>std::vector&lt;int&gt; a; std::string line; std::cout &lt;&lt; "..." &lt;&lt; std::endl; while ( std::getline( std::cin, line ) &amp;&amp; !line.empty() ) { std::istringstream parse( line ); int value; parse &gt;&gt; value &gt;&gt; std::ws; if ( !parse ) { std::cout &lt;&lt; "That wasn't an integer, try again" &lt;&lt; std::endl; } else if ( parse.get() != EOF ) { std::cout &lt;&lt; "Extra garbage at end of line, ignoring it" &lt;&lt; std::endl; } else { a.push_back( value ); } } </code></pre> <p>(You'll note that I've used <code>std::vector</code>, since you don't know up front how many inputs you'll get.)</p> <p>If you really want to use ESC, you'll probably need a third party library, along the lines of <code>curses</code>, to do raw input, reading one character at a time, and collecting the digits into a string, for conversion using <code>std::istringstream</code>.</p>
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    1. USJames Kanze
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    1. COThe vector alternative is great but using Esc is imperative. Thank you for the hint!
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    2. CO@Georgiana Then you can't use `std::cin`. I've just tested under Windows, and in a console window, at least, the escape key will never end up in the stream. If you're not worried about portability, then perhaps `getch` could be used, but it could be tricky.
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