Is there any way to know if an arraylist contains a piece of text?

Question

I have an arraylist with several items. Let\'s say they are: \"DARK BROWN\", \"BLUE\", \"GREEN\",....

Is there any way to look for if there\'s the string \"DARK\" in

Answer 1

it seems to be a very slow method because the arraylist can contain a lot of elements.

Like, a million?

Nov 30, 2012 10:05:20 AM test.t100.t001.ArrayListSpeed main
INFO: Creating entries.
Nov 30, 2012 10:05:21 AM test.t100.t001.ArrayListSpeed main
INFO: Searching..
Nov 30, 2012 10:05:21 AM test.t100.t001.ArrayListSpeed main
INFO: Searching 'dark' 333716
Nov 30, 2012 10:05:21 AM test.t100.t001.ArrayListSpeed main
INFO: Searching 'light' 333333
Nov 30, 2012 10:05:22 AM test.t100.t001.ArrayListSpeed main
INFO: Searching 'plain' 332951

Code

package test.t100.t001;

import java.util.ArrayList;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;

public class ArrayListSpeed {

    public static String[] PREFIX = {"Dark ", "Light ", "Plain "};
    public static String[] COLOR = {"Red", "Green", "Blue"};

    public static String getColor(Random r) {
        int val = r.nextInt(COLOR.length);
        return COLOR[val];
    }

    public static String getPrefix(Random r) {
        int val = r.nextInt(PREFIX.length);
        return PREFIX[val];
    }

    public static int countPrefixes(ArrayList list, String prefix) {
        int count = 0;
        for (String val : list) {
            if (val.toLowerCase().startsWith(prefix.toLowerCase())) {
                count++;
            }
        }
        return count;
    }

    public static void main(String[] args) {
        Logger logger = Logger.getAnonymousLogger();
        ArrayList list = new ArrayList();
        Random r = new Random();
        logger.log(Level.INFO, "Creating entries.");
        for (int ii=0; ii<1000000; ii++) {
            list.add( getPrefix(r) + getColor(r) );
        }
        logger.log(Level.INFO, "Searching..");
        logger.log(Level.INFO, 
                "Searching 'dark' " + countPrefixes(list,"dark"));
        logger.log(Level.INFO, 
                "Searching 'light' " + countPrefixes(list,"light"));
        logger.log(Level.INFO, 
                "Searching 'plain' " + countPrefixes(list,"plain"));
    } 
}