Thread: Collections

I study a tutorial about JAVA and this was an example of it about collections.However when i try to call method sort,the system can not find it.Why?I have imported java.util.*

 
package collections;
 
import java.util.*;//library
 
public class Collections {
 
    //Purpose:Create an ArrayList which stores strings
    public static void main(String[] args) {
        List<String> l = new ArrayList();
 
        String first="Hello";
 
        l.add(first);
        l.add(" world");
        l.add("JAVA");
 
        l.set(2,"JAVA2");//set modifies a value of the list
 
        Collections.sort(l);//sort the list
 
        System.out.println(l);
        System.out.println("Size of the list = " + l.size());
 
        int i = l.indexOf(" world");//will return the position of <world>
        System.out.println("String <world> is at " + i + " cell");
 
        l.remove("JAVA2");//will remove the first appearence of <JAVA2>
 
        l.clear();//removes all the elements of the list
        if(l.isEmpty()) 
            System.out.println("empty list");
        System.out.println(l);
    }
}

The error occurs at this line Collections.sort(l);//sort the list

Your class's name is also Collections, try renaming your class and see what happens

Hmm..I see what happened.Thank you very much!