Regular Expressions

Match Patterns ("[]")

• The "[]" symbols allow you to specify a class of characters to be matched at a single position .
• Example:
  

  $theVar = "This is a test";
  if ($theVar =~ /is [aA] tes/) {
      (print "Match One\n");  # Would Match
  }
  $theVar = "This is A test";
  if ($theVar =~ /is [aA] tes/) {
      (print "Match Two\n");  # Would Also Match
  }
  

• You can put as many characters in the brackets as you wish.
• You can specify a range of values with the "-" symbol.
• Example:
  

  $theVar =~ [0-9] # same as [0123456789]
  $theVar =~ [a-z] # same as [abcdefghijklmnopqrstuvwxyz]
  $theVar =~ [A-Z] # same as [ABCDEFGHIJKLMNOPQRSTUVWXYZ]
  $theVar =~ [0-9a-zA-Z] # All of the above
  $theVar =~ [aeiou24680] # Vowels and even digits
  $theVar =~ [a-kA-K] # A thru K in alphabet, ignore case