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copied!<p>There's no standard and <em>fast</em> way to do this. I can think of some options.</p> <hr> <p>Suppose we have:</p> <pre><code>char *text = new char[20]; cin >> text; </code></pre> <p>Note - we <strong><em>need</em></strong> to know that the capacity is 20! I'd recommend you to use some constant for this, especially if this will be used for other strings, too.</p> <hr> <p>Okay, first option - use <code>std::stringstream</code></p> <pre><code>std::stringstream ss; ss << setw( 20 - 1 ) << setfill( '-' ) << text; // ^^^^ we need one byte for the '\0' char at the end ss >> text; </code></pre> <p>But this is rather slow. </p> <hr> <p>Fill the chars by hand:</p> <pre><code>int length = strlen( text ); for( int i = length; i < 20 - 1; ++i ) // again - "20-1" - '\0' { text[ i ] = '-'; } text[ 20 - 1 ] = '\0'; // don't forget to NULL-terminate the string </code></pre> <hr> <p>And <strong><em>the best way</em></strong>, according to me - get rid of these <code>char*</code> things (you have tagged the question as <a href="/questions/tagged/c%2b%2b" class="post-tag" title="show questions tagged 'c++'" rel="tag">c++</a> ) and just use <code>std::string</code>.</p> <pre><code>std::string sText; std::cin >> sText; sText.resize( 20, '-' ); // NOTE - no need to NULL-terminate anything </code></pre> <p><em><strong>Voilà!</em></strong> (:</p> <p>This way is much more clear and you don't need to carry about using <code>delete[] text;</code> at the end (which is not that trivial sometimes, especially in case of some exception before <code>delete[]</code> - this will give you 100% memory leak. Of course, you can always use smart pointers.. but smart pointers for this?! :) )</p> <hr> <p>Of course, you can write <code>19</code> instead of <code>20-1</code>, I just wanted to "highlight" the <code>-1</code>, in case that you use some constant. </p>

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