PHP
<span class="syntaxdefault">function checkString</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">$v</span><span class="syntaxkeyword">)<br />{<br /></span><span class="syntaxdefault"> for</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">$i </span><span class="syntaxkeyword">=</span><span class="syntaxdefault"> 1</span><span class="syntaxkeyword">;</span><span class="syntaxdefault"> $i </span><span class="syntaxkeyword"><=</span><span class="syntaxdefault"> strlen</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">$v</span><span class="syntaxkeyword">);</span><span class="syntaxdefault"> $i</span><span class="syntaxkeyword">++)<br /></span><span class="syntaxdefault"> if</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">is_int</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">substr</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">$v</span><span class="syntaxkeyword">,</span><span class="syntaxdefault"> $i</span><span class="syntaxkeyword">,</span><span class="syntaxdefault"> $i</span><span class="syntaxkeyword">++)))<br /></span><span class="syntaxdefault"> </span><span class="syntaxkeyword">{<br /></span><span class="syntaxdefault"> return false</span><span class="syntaxkeyword">;<br /></span><span class="syntaxdefault"> return true</span><span class="syntaxkeyword">;<br /></span><span class="syntaxdefault"> </span><span class="syntaxkeyword">}<br />}<br /></span><span class="syntaxdefault"> </span>
Er liest den 1. Buchstaben ein und gibt sofort irgendwas zurück, so wird nur ein Buchstabe geprüft, ich habe es noch mal geblockt:
PHP
<span class="syntaxhtml"><br /><span class="syntaxdefault"><?php<br /> </span><span class="syntaxkeyword">function </span><span class="syntaxdefault">checkString</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">$v</span><span class="syntaxkeyword">)<br /> {<br /> for(</span><span class="syntaxdefault">$i </span><span class="syntaxkeyword">= </span><span class="syntaxdefault">1</span><span class="syntaxkeyword">; </span><span class="syntaxdefault">$i </span><span class="syntaxkeyword"><= </span><span class="syntaxdefault">strlen</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">$v</span><span class="syntaxkeyword">); </span><span class="syntaxdefault">$i</span><span class="syntaxkeyword">++)<br /> {<br /> if(!</span><span class="syntaxdefault">is_int</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">substr</span><span class="syntaxkeyword">(</span><span class="syntaxdefault">$v</span><span class="syntaxkeyword">, </span><span class="syntaxdefault">$i</span><span class="syntaxkeyword">, </span><span class="syntaxdefault">$i</span><span class="syntaxkeyword">++)))<br /> {<br /> return </span><span class="syntaxdefault">false</span><span class="syntaxkeyword">;<br /> }<br /> } <br /> return </span><span class="syntaxdefault">true</span><span class="syntaxkeyword">;<br /> } <br /></span><span class="syntaxdefault">?><br /></span></span>