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    <blockquote> <p><strong>Why are strings in C++ usually terminated with <code>'\0'</code>?</strong></p> </blockquote> <p>Note that C++ Strings and C strings are not the same.<br> In C++ string refers to <strong><a href="http://www.cplusplus.com/reference/string/string/" rel="noreferrer">std::string</a></strong> which is a template class and provides a lot of intuitive functions to handle the string.<br> Note that C++ std::string are not <code>\0</code> terminated, but the class provides functions to fetch the underlying string data as <code>\0</code> terminated c-style string.</p> <p>In C a string is collection of characters. This collection usually ends with a <code>\0</code>.<br> Unless a special character like <code>\0</code> is used there would be no way of knowing when a string ends.<br> It is also aptly known as the string null terminator. </p> <p>Ofcourse, there could be other ways of bookkeeping to track the length of the string, but using a special character has two straight advantages: </p> <ul> <li>It is more intuitive and </li> <li>There are no additional overheads</li> </ul> <p>Note that <code>\0</code> is needed because most of Standard C library functions operate on strings assuming they are <code>\0</code> terminated.<br> For example:<br> While using <code>printf()</code> if you have an string which is not <code>\0</code>terminated then <code>printf()</code> keeps writing characters to <code>stdout</code> until a <code>\0</code> is encountered, in short it might even print garbage. </p> <blockquote> <p><strong>Why should we use <code>'\0'</code> here?</strong></p> </blockquote> <p>There are two scenarios when you do not need to <code>\0</code> terminate a string:</p> <ul> <li>In any usage if you are explicitly bookkeeping length of the string and </li> <li>If you are using some standard library api will implicitly add a <code>\0</code> to strings. </li> </ul> <p>In your case you already have the second scenario working for you.</p> <pre><code>array[s.size()] = '\0'; </code></pre> <p>The above code statement is redundant in your example. </p> <p>For your example using <code>strncpy()</code> makes it useless. <code>strncpy()</code> copies <code>s.size()</code> characters to your <code>array</code>, Note that it appends a null termination if there is any space left after copying the strings. Since <code>array</code>is of size <code>s.size() + 1</code> a <code>\0</code> is automagically added. </p>
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    1. POWhy are strings in C++ usually terminated with '\0'?
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    1. CONot necessarily. You can also store an arbitary-length array by keeping the length somewhere (like how Java works.. I assume).
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    2. CO@BrendanLong: Hope that answers.
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    3. CO@BrendanLong I'm assuming edit went through after that comment but as pointed out it removes additional overhead. To do it the way you're suggesting you would need to make a struct with an int as well as the array and that would offer worse performance and consume more memory.
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