title: Check if the first element of an array is a digit in C
body: <p>I was making a program to take a list of data and separate it by the "," in the file. However, some items had multiple commas. </p>
  
  <p>Is there any <em>efficient</em> way of checking the first character of an array? For example: </p>
  
  <pre><code>char *array = {'1','A','C','D','5'};
  </code></pre>
  
  <p>Now, I want to only do <code>somefunction(array)</code> if <code>array</code> starts with a digit, even if it is in char format. So in this example, let <code>somemethod</code> be the way of determining if the first element is an integer: </p>
  
  <pre><code>char *array = {'1','A','C','D','5'};
  if( somemethod ) someaction(array); 
  </code></pre>
  
  <p>How could I do this efficiently? </p>