RegEx for matching A-Z a-z 0-9 and

Question

I need a regex which will allow only A-Z  a-z  0-9  the   character  and dot     in the input    I tried    A-Za-z0-9       But  it did not work  How can I fix it

User · Answer

You could simply use    w    to match A-Z  a-z  0-9 and

User · Answer

regex     a-zA-Z0-9     i  This works

User · Answer

Working from what you ve given I ll assume you want to check that someone has NOT entered any letters other than the ones you ve listed  For that to work you want to search for any characters other than those listed     A-Za-z0-9      And use that in a match in your code  something like   if      A-Za-z0-9     match  your input string          alert   you have entered invalid data         Hows that

User · Answer

A-Za-z0-9        From beginning until the end of the string  match one or more of these characters   Edit   Note that   and   match the beginning and the end of a line  When multiline is enabled  this can mean that one line matches  but not the complete string   Use  A for the beginning of the string  and  z for the end   See for example  http   msdn microsoft com en-us library h5181w5w v vs 110  aspx

User · Answer

Maybe  you need to specify more exactly what didn t work and in what environment you are   As to the claim that the dot is special in a charackter class  this is not true in every programming environment  For example the following perl script   use warnings  use strict   my  str               str    s  A-Za-z    X g  print   str n     produces     X

[regex] RegEx for matching "A-Z, a-z, 0-9, _" and "."

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