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POHelp with reversing a string in C
 

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  1. POHelp with reversing a string in C
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    <p>I am trying to reverse a character string in C</p> <p>Here is what I have</p> <pre><code>void reverse(char str[]) { int i = 0; int length; // Get string length for (i = 0; str[i] != '\0' ; ++i) { length = i; } char reversed[1000]; int j; j = 0; // Reverse it for (j = 0; j &lt; length ; ++j) { reversed[j] = str[length - j]; } } </code></pre> <p>I know that <code>reversed</code> contains the string reversed, but I'm not sure how to modify the original <code>str</code> without throwing away data I need.</p> <p>I also don't know how to set <code>str</code>to <code>reversed</code> without looping <em>again</em>.</p> <p>Would it be acceptable to do another...</p> <pre><code> int m; m = 0; for (m = 0; m &lt; length ; ++m) { str[j] = reversed[j]; } </code></pre> <p>Usually I'd say this many loops smells, but I'm also still quite unfamiliar with the language so I'm not sure...</p> <h2>Update</h2> <p>Thanks for all the answers guys, and I appreciate the edits too!</p> <p>I ended up going with <a href="http://codepad.org/tQmMFzFq" rel="nofollow noreferrer">this</a>...</p> <pre><code>int main() { char str[] = "Reverse me!"; int length; for (length = 0; str[length] != '\0'; length++) { } printf("length =&gt; %d chars\n", length); int j, k; char c; for (j = 0, k = length - 1; j &lt; k; j++, k--) { c = str[k]; str[k] = str[j]; str[j] = c; } printf("reversed =&gt; %s\n", str); return 0; } </code></pre> <p>Some things I now know...</p> <ul> <li>There is a <code>strlen()</code> like in PHP. However, it has not been discussed in the book yet, plus I need to get familiar with null terminated strings.</li> <li>A <code>for</code> loop can assign and do multiple things that are comma separated. I never knew this! </li> </ul> <p>So asking was worthwhile :)</p>
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    1. COPlease mark Homework with the [homework] tag. Also, please search. This is asked very, very frequently.
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    2. CO@S.Lott This isn't homework, well at least not for any educational faculty. This is for my own interests. Also, since I'm new to C, I wasn't sure what I should be searching for. But if it's a duplicate, let me know so I can vote to close. Thanks
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    3. COSee your copy of K&R2, page 62.
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