CODEWITHSUNDEEP
javaregex
user1194310
user1194310

Reputation: 129

Need regex to match the given string

I need a regex to match a particular string, say 1.4.5 in the below string . My string will be like 

absdfsdfsdfc1.4.5kdecsdfsdff

I have a regex which is giving [c1.4.5k] as an output. But I want to match only 1.4.5. I have tried this pattern: 

[^\\W](\\d\\.\\d\\.\\d)[^\\d]

But no luck. I am using Java. Please let me know the pattern.

Upvotes: 2

Views: 175

Answers (6)

Raghunandan
Raghunandan

Reputation: 133560

String str= "absdfsdfsdfc**1.4.5**kdec456456.567sdfsdff22.33.55ffkidhfuh122.33.44"; 
String regex ="[0-9]{1}\\.[0-9]{1}\\.[0-9]{1}";  
Matcher matcher = Pattern.compile( regex ).matcher( str);                    
if (matcher.find())
{
String year = matcher.group(0);

System.out.println(year);
}
else
{
    System.out.println("no match found");
}

Upvotes: 0

botkop
botkop

Reputation: 964

Regular Expression

((?<!\d)\d(?:\.\d(?!\d))+)

As a Java string:

"((?<!\\d)\\d(?:\\.\\d(?!\\d))+)"

Upvotes: 0

Mithrandir
Mithrandir

Reputation: 25337

I think this one should do it : ([0-9]+\\.?)+

Upvotes: 0

pogo
pogo

Reputation: 1550

Use look ahead and look behind. 

(?<=c)[\d\.]+(?=k)

Where c is the character that would be immediately before the 1.4.5 and k is the character immediately after 1.4.5. You can replace c and k with any regular expression that would suit your purposes

Upvotes: 0

stema
stema

Reputation: 92976

When I read your expression [^\\W](\\d\\.\\d\\.\\d)[^\\d] correctly, then you want a word character before and not a digit ahead. Is that correct?

For that you can use lookbehind and lookahead assertions. Those assertions do only check their condition, but they do not match, therefore that stuff is not included in the result.

(?<=\\w)(\\d\\.\\d\\.\\d)(?!\\d)

Because of that, you can remove the capturing group. You are also repeating yourself in the pattern, you can simplify that, too:

(?<=\\w)\\d(?:\\.\\d){2}(?!\\d)

Would be my pattern for that. (The ?: is a non capturing group)

Upvotes: 1

speakingcode
speakingcode

Reputation: 1506

Your requirements are vague. Do you need to match a series of exactly 3 numbers with exactly two dots?

[0-9]+\.[0-9]+\.[0-9]+

Which could be written as

([0-9]+\.){2}[0-9]+

Do you need to match x many cases of a number, seperated by x-1 dots in between?

([0-9]+\.)+[0-9]+

Upvotes: 0

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