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Regular expression basics

Below are some representations for Regex 

  • Single occurrence of Any character in a string can be replaced by     .
  • Zero or more occurrences of any character                                         *
  • To represent whitespaces                                                                     \s
  • One of the character inside square bracket (eg. any char a, b or c)     [abc] 

  • Exclusion of characters -except anyone inside square bracket in single position
            (eg. non of the char a, b or c)                                                              [^abc]                                                                                                            
  • One of the character falling in the range given in square brackets                                                                 (eg. a to d -a, b, c or d)                                                                   [a-d]

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