user78454: In my Arduino project, a string will be received. I understand using .indexof to find the placement of a certain character in the string. My problem is that I need to find the first occurrence of any letter A-Z and haven't found any resources regarding using or  statements in an .indexof aka string.indexof("a" || "b" ....).
Is this something that is not possible using indexof functions and if so is there any function that I can use to solve this! Thanks!

user78445: Here are two functions that I hope help in your endeavours. You can supply either a String or a char array and you should get the first position of an alpha character. Returns -1 if not present.
See https://www.arduino.cc/reference/en/language/functions/characters/isalpha/
Update:
Thanks to great comments from Edgar & Mat I have updated the functions with best practise and cost improvements.
int alphaPos(const char* str)
{
  for (int i = 0; str[i] !=0 ; ++i) {
    if (isAlpha(str[i]))
    {
      return i;
    }
  }
  
  return -1;
}


int alphaPos(const String& str)
{
  return alphaPos(str.c_str());
}

/*
    Usage:

    String bobble = "&&&88434a";
    int x = alphaPos(bobble);

    if (x != -1) 
    {
      ...x has the position in the string
    }
    else
    {
     ...There is no alpha char present.
    }
*/


78454: <p>In my Arduino project, a string will be received. I understand using <code>.indexof</code> to find the placement of a certain character in the string. My problem is that I need to find the first occurrence of any letter A-Z and haven't found any resources regarding using <code>or</code>  statements in an <code>.indexof</code> aka <code>string.indexof(&quot;a&quot; || &quot;b&quot; ....)</code>.</p>
<p>Is this something that is not possible using indexof functions and if so is there any function that I can use to solve this! Thanks!</p>
 78445: <p>Here are two functions that I hope help in your endeavours. You can supply either a String or a char array and you should get the first position of an alpha character. Returns -1 if not present.</p>
<p>See <a href="https://www.arduino.cc/reference/en/language/functions/characters/isalpha/" rel="nofollow noreferrer">https://www.arduino.cc/reference/en/language/functions/characters/isalpha/</a></p>
<p>Update:</p>
<p>Thanks to great comments from Edgar &amp; Mat I have updated the functions with best practise and cost improvements.</p>
<pre class="lang-cpp prettyprint-override"><code>int alphaPos(const char* str)
{
  for (int i = 0; str[i] !=0 ; ++i) {
    if (isAlpha(str[i]))
    {
      return i;
    }
  }
  
  return -1;
}


int alphaPos(const String&amp; str)
{
  return alphaPos(str.c_str());
}

/*
    Usage:

    String bobble = &quot;&amp;&amp;&amp;88434a&quot;;
    int x = alphaPos(bobble);

    if (x != -1) 
    {
      ...x has the position in the string
    }
    else
    {
     ...There is no alpha char present.
    }
*/
</code></pre>
