Thread: Using Regular Expression (regex) in Java Programming

Hiii all,

I'm new in using Regular Expression in Java.

For example, I have String s like this:

String s = "Why John Smith and Alan Smith and Nick Gates are the same?"

How can I get sub-strings as "John Smith", "Alan Smith", "Nick Gates" - (names of people - with first upper character) from s by using regex?

I try to use regex in Java, but It totally doesn't work.

This is my code:
/*

String EXAMPLE_TEST = "Why John Smith and Alan Smith and Nick Gates are the same?";
System.out.println(EXAMPLE_TEST.matches("([A-Z]&&[a-z])"));
String[] splitString = (EXAMPLE_TEST.split("([A-Z]&&[a-z])"));
System.out.println(splitString.length);
for (String string : splitString) {
System.out.println(string);
}

*/


Please help me to have exact "regex" in this case.

Thanks all in advance!

If all you want are words that begin with capital letters, it's much easier to not use your own regex and simply use the Scanner.next() method to get the word, at which point you can check to see if the first letter is upper case.

Scanner reader = new Scanner(EXAMPLE_TEST); // using the string you provided
while (reader.hasNext())
{
     String read = reader.next();
     if (Character.isUpperCase(read.charAt(0))
     {
          System.out.println("Found a name: " + read);
     }
}

There are going to be a few problems with this basic code, such as it will pick up the first letter of the sentence, and it will also pick up abbreviations/other proper nouns that happen to have the first letter capitalized. Unfortunately, there's not really a way to get around this problem without doing some pretty advanced contenxt handling and/or natural language processing.