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Regex  RSS feed

 
Ranch Hand
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Hi,

I want to find if a String has only special characters and no Alpha numberic characters...Can anybody please provide the Regex for this?

Thanks in advance
 
Bartender
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I don't have a lot of experience with Regexes.... I might just iterate through the string and check each character with the Character.isLetterOrDigit() method.

I am interested to see what kind of responses come of this.... I always like to learn ways to "work smarter not harder"
 
Ranch Hand
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Do a search on regular expressions in JavaRanch forum you will find many posts related to this.
Refer Pattern & Regular Expressions
Predefined character classes : \W
POSIX character classes (US-ASCII only): \p{Punct}
Is that helpful for you to find special characters?
 
Sheriff
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You can use [^ABCD] to find match anything but A, B, C or D. I'm sure you can use that.
 
Mary Cole
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The thing is that I want to know if the String has only NON alpha numeric characters..am having problem in coming up with a regex for it.
 
Rob Spoor
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If a number has only non-alphanumeric characters, it does not have any alphanumeric characters. Instead of checking if all characters are non-alphanumeric, check if at least one character is alphanumeric and then negate the result.
 
Mary Cole
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The above code is giving me false for bothe lookin values...don't know where am wrong
 
Rob Spoor
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1) remove the , from your regex' character class. By adding them you specify that , is part of the character class, therefore you are disallowing , as well.

2) Your regex is only testing for one single character. Check out the quantifiers sections of java.util.regex.Pattern
 
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