[Q#2367381][A#2367418] How to extract numbers from a string and get an array of ints?

https://stackoverflow.com/q/2367381

I have a String variable (basically an English sentence with an unspecified number of numbers) and I'd like to extract all the numbers into an array of integers. I was wondering whether there was a quick solution with regular expressions? I used Sean's solution and changed it slightly:

Answer

https://stackoverflow.com/a/2367418

… prints -2 and 12. -? matches a leading negative sign – optionally. \d matches a digit, and we need to write \ as \ in a Java String though. So, \d+ matches 1 or more digits.

APIzation

Pattern p = Pattern.compile("-?\\d+");
Matcher m = p.matcher("There are more than -2 and less than 12 numbers here");
while (m.find()) {
  System.out.println(m.group());
}

package com.stackoverflow.api;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Human2367418 {

  public static List<String> extractNumbersFromString(final String s) {
    List<String> numbers = new ArrayList<>();
    Pattern p = Pattern.compile("-?\\d+");
    Matcher m = p.matcher(s);
    while (m.find()) {
      System.out.println(m.group());
      numbers.add(m.group());
    }
    return numbers;
  }
}

package com.stackoverflow.api;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * How to extract numbers from a string and get an array of ints?
 *
 * @author APIzator
 * @see <a href="https://stackoverflow.com/a/2367418">https://stackoverflow.com/a/2367418</a>
 */
public class APIzator2367418 {

  public static void extractNumber() throws Exception {
    Pattern p = Pattern.compile("-?\\d+");
    Matcher m = p.matcher(
      "There are more than -2 and less than 12 numbers here"
    );
    while (m.find()) {
      System.out.println(m.group());
    }
  }
}