title: preg_match(): Compilation failed: character value in \x{} or \o{} is too large at offset 27 on line number 25
body: <p>I am writing up some PHP code. In this code, I am running a for loop within a for loop to iterate over an array, then to iterate over the characters in the current string in the array.</p>
  
  <p>I then want to do preg_match() on the current string to see if it matches a rather ling RegEx.</p>
  
  <pre><code>preg_match('/[ \f\n\r\t\v\x{00a0}\x{1680}\x{180e}\x{2000-}\x{200a}\x{2028}\x{2029}\x{202f}\x{205f}\x{3000}\x{feff}]/', $input[$i][$j])
  </code></pre>
  
  <p>But I keep on receiving the following error:</p>
  
  <blockquote>
    <p>WARNING preg_match(): Compilation failed: character value in \x{} or
    \o{} is too large at offset 27 on line number 25</p>
  </blockquote>