title: PHP Search in array for a string do not need an exact match
body: <p>I have tried to Google this but can only get examples for exact matches in an array or character searches.</p>
  
  <p>My question is. I have two arrays one will be an array of loan numbers. 
  The second will be an array of Pdf files in a folder. For demonstration purposes, I have hardcoded the file names into an array. 
  How do I search an array for a string which is not an exact match?
  If this is not possible is there another approach? </p>
  
  <p>I have tried to use a set of substring function to get the loan number but as the loan number is the dynamic length it is not a valid option.</p>
  
  <p>Below is an example of what my arrays will be like </p>
  
  <pre><code>&lt;?php
  
  $Csv_array=array();
  $Folder_array = array();
  
  $line_number = false;
  
  
  array_push($Csv_array,'234234','45454','78797');
  
  
  
  
  array_push($Folder_array,'723325_Test_letter.pdf','753434_Test_letter.pdf','75443434_Test_letter.pdf');
  
  
  
  ?&gt;
  </code></pre>