I would like to see if a . exists in a string followed by a number
E.g 123.456 = True
E.g 123456. = False
E.g 123456 = False
E.g 123.456. = True
Any Regex genius out there?
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1this is a very basic regex, you do not need a genius, even i can answer.Victor Mukherjee– Victor Mukherjee2012-10-08 21:15:49 +00:00Commented Oct 8, 2012 at 21:15
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the question is easy if you know the answeruser1438082– user14380822012-10-08 21:26:59 +00:00Commented Oct 8, 2012 at 21:26
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3 Answers
\.(?=[0-9])
matches a dot iff it's followed by a digit. In Java, that is
Pattern regex = Pattern.compile("\\.(?=[0-9])");
Matcher regexMatcher = regex.matcher(subjectString);
foundMatch = regexMatcher.find();
4 Comments
bozdoz
How does this compare to
\.\d?
Tim Pietzcker
Your regex also matches the digit, mine only matches the dot (if it's followed by a digit). The OP's question is a bit vague on whether he wants the digit to be part of the match. It probably doesn't matter...
Victor Mukherjee
sorry, but still cannot understand. could you please explain what does that '?=' mean?
user1438082
thanks a million. im very new to java . To clarify solution i done the following which works. import java.util.regex.Matcher; import java.util.regex.Pattern; Pattern regex = Pattern.compile("\\.(?=[0-9])"); Matcher regexMatcher = regex.matcher(currentNumber); boolean foundMatch = regexMatcher.find(); if (foundMatch) { // do nothing as decimal point already exists } else { decimalPointActive = true; }
Regex would be '\\.\\d' I believe
1 Comment
Tim Pietzcker
Don't forget to escape the backslashes.
This works fine:
String regex="\\.\\d";
