Question

i am having a string arraylist ‘names’.which contains names of people.i want to sort the arraylist in alphabetical order.plz help me

Answer 1

This will solve your problem…

ArrayList arrayList = new ArrayList();

//Add elements to Arraylist
arrayList.add("1");
arrayList.add("3");
arrayList.add("5");
arrayList.add("2");
arrayList.add("4");


Collections.sort(arrayList);

//display elements of ArrayList
System.out.println("ArrayList elements after sorting in ascending order : ");
for(int i=0; i<arrayList.size(); i++)
    System.out.println(arrayList.get(i));

To sort an ArrayList object, use Collection.sort method. This is a
static method. It sorts an ArrayList object’s elements into ascending order.

Just in case if the below code in comment doesnt work means…
Try this code..

Create a custom comparator class:

import java.util.Comparator;

class IgnoreCaseComparator implements Comparator<String> {
  public int compare(String strA, String strB) {
    return strA.compareToIgnoreCase(strB);
  }
}

Then on your sort:

IgnoreCaseComparator icc = new IgnoreCaseComparator();

java.util.Collections.sort(arrayList,icc);