for example, i have string "john smith 12 03 1993" task is to eject john smith to another one. Now i'm trying to use regex [a-z]\s(java validate) but it not works giving just "smith" without john
String test = "john smith 11 12323 2323";
Pattern pattern = Pattern.compile("[a-z]*\\s*");
Matcher matcher = pattern.matcher(test);
matcher.matches();
matcher.find();
System.out.println(matcher.group());
You only match 1 chunk of 0+ letters and 0+ whitespaces.
You need to use matcher.find() in a while loop and use a regex like [a-z]+ or \b[a-z]+\b:
String test = "john smith 11 12323 2323";
Pattern pattern = Pattern.compile("[a-z]+");
Matcher matcher = pattern.matcher(test);
while (matcher.find()) {
System.out.println(matcher.group());
}
// => john, smith
See the Java demo.
If you need to match "words" before whitespace/end of string, use "\\b[a-z]+(?!\\S)" regex.
To match john smith you may use "^[a-z]+(?:\\s+[a-z]+)*" regex (and then you may replace while with if since you only expect 1 match).
String test = "john smith 11 12323 2323";
Pattern pattern = Pattern.compile("^[a-z]+(?:\\s+[a-z]+)*");
Matcher matcher = pattern.matcher(test);
if (matcher.find()) {
System.out.println(matcher.group());
} // => john smith
See this Java demo.
String test = "john smith 11 12323 2323";
Pattern pattern = Pattern.compile("^([a-z]+ [a-z]+).*");
Matcher matcher = pattern.matcher(test);
matcher.matches();
System.out.println(matcher.group(1));
group(0) is always the entire String (test). Replace ^ with .* if the word is not the first thing in "test"
Java has some tools to make this easier: named groups in particular allow you to write readable regex and extract fields with ease:
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Class {
public static void main(String... args) {
final String test = "Андрей Парфёнов 05 15 1955";
final Pattern pattern = Pattern.compile("" +
"^(?<name>" +
"(?<firstName>.+)\\s+" +
"(?<lastName>.+))\\s+" +
"(?<date>" +
"(?<month>\\d{2})\\s+" +
"(?<day>\\d{2})\\s+" +
"(?<year>\\d{4}))$");
final Matcher matcher = pattern.matcher(test);
matcher.matches();
System.out.println(matcher.group("name"));
}
}
String.split(" ")