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POHow to find first non-repetitive character from a string?
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copied!<p>I've spent half day trying to figure out this and finally I got working solution. However, I feel like this can be done in simpler way. I think this code is not really readable.</p> <p>Problem: Find first non-repetitive character from a string.</p> <p>$string = "abbcabz"</p> <p>In this case, the function should output "c".</p> <p>The reason I use concatenation instead of <code>$input[index_to_remove] = ''</code> in order to remove character from a given string is because if I do that, it actually just leave empty cell so that my return value $input[0] does not not return the character I want to return.</p> <p>For instance, </p> <pre><code>$str = "abc"; $str[0] = ''; echo $str; </code></pre> <p>This will output "bc"</p> <p>But actually if I test,</p> <pre><code>var_dump($str); </code></pre> <p>it will give me:</p> <pre><code>string(3) "bc" </code></pre> <p>Here is my intention:</p> <pre><code>Given: input while first char exists in substring of input { get index_to_remove input = chars left of index_to_remove . chars right of index_to_remove if dupe of first char is not found from substring remove first char from input } return first char of input </code></pre> <p>Code:</p> <pre><code>function find_first_non_repetitive2($input) { while(strpos(substr($input, 1), $input[0]) !== false) { $index_to_remove = strpos(substr($input,1), $input[0]) + 1; $input = substr($input, 0, $index_to_remove) . substr($input, $index_to_remove + 1); if(strpos(substr($input, 1), $input[0]) == false) { $input = substr($input, 1); } } return $input[0]; } </code></pre>

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