I have one input String like this:
"I am Duc/N Ta/N Van/N"
String "/N" present it is the Name of one person.
The expected output is:
Name: Duc Ta Van
How can I do it by using regular expression?
3 Answers
You can use Pattern and Matcher like this :
String input = "I am Duc/N Ta/N Van/N";
Pattern pattern = Pattern.compile("([^\\s]+)/N");
Matcher matcher = pattern.matcher(input);
String result = "";
while (matcher.find()) {
result+= matcher.group(1) + " ";
}
System.out.println("Name: " + result.trim());
Output
Name: Duc Ta Van
Another Solution using Java 9+
From Java9+ you can use Matcher::results like this :
String input = "I am Duc/N Ta/N Van/N";
String regex = "([^\\s]+)/N";
Pattern pattern = Pattern.compile(regex);
Matcher matcher = pattern.matcher(input);
String result = matcher.results().map(s -> s.group(1)).collect(Collectors.joining(" "));
System.out.println("Name: " + result); // Name: Duc Ta Van
3 Comments
AndroidTa
Thanks a lot @YCF_L
AxelH
That java 9 solution is excellent. I really need to update my systems!
Youcef LAIDANI
This is correct @AxelH it is the time for us to move to Java 10 :)
Here is the regex to use to capture every "name" preceded by a /N
(\w+)\/N
Validate with Regex101
Now, you just need to loop on every match in that String and concatenate the to get the result :
String pattern = "(\\w+)\\/N";
String test = "I am Duc/N Ta/N Van/N";
Matcher m = Pattern.compile(pattern).matcher(test);
StringBuilder sbNames = new StringBuilder();
while(m.find()){
sbNames.append(m.group(1)).append(" ");
}
System.out.println(sbNames.toString());
Duc Ta Van
It is giving you the hardest part. I let you adapt this to match your need.
Note :
In java, it is not required to escape a forward slash, but to use the same regex in the entire answer, I will keep "(\\w+)\\/N", but "(\\w+)/N" will work as well.
1 Comment
AxelH
Yeah I notice that... strangely regex101 asked for "/" to be escaped ... Since it was working I kept it in the java to use the same regex and kept the link to show the dynamic match. But thanks @YCF_L EDIT: this is the delimiter for the flags... I am stupid ;) java doesn't support them.
I've used "[/N]+" as the regular expression.
[] = Matches characters inside the set
\/ = Matches the character / literally (case sensitive)
+ = Matches between one and unlimited times, as many times as possible, giving back as needed (greedy)
6 Comments
Alex
P.S. This regex can be used to remove
/N out of the string.AxelH
You will still find the rest of the
String that is not followed by /N and that is not a name. n the example I am is not needed.Alex
AxelH I haven't touched regex since 2nd year of college, my bad :)
AxelH
That's not about the regex, but about the question itself. It is not only the remove
/N but to extract the word before every /N.Alex
Ahh okay. I re-read the question there! Cheers. Does
(\w+) do the actual grouping/extraction? |
Name: Duc Ta Vanas result or/N: Duc Ta Van? Are the literals Duc, Ta and Van always the same?String. The regex is simple to write after that.