Make list element case-insensitive

[satya pksh]

In my java application i need to compare two list's element whether it is similar or not.

In short suppose i have two list declared like shown below

List a = new ArrayList();
a.add("one"); 
a.add("three"); 
a.add("two"); 
Collections.sort(a);

List a1 = new ArrayList(); 
a1.add("ONE"); 
a1.add("two"); 
a1.add("THREE"); 
Collections.sort(a);

If i write a condition for equality it fails as some of list's element is in different case like

if(a.equals(a1)){ 
System.out.println("equal"); 
} 
else{ 
System.out.println("not equal");
 }

It will display result "Not equal"

So please tell me how i can make the list element case-insensitive in java language only.

Thank and regard

[Campbell Ritchie]

Try looking in the API for String where you will probably find something useful very quickly.

[Joanne Neal]

Campbell Ritchie wrote:Try looking in the API for String where you will probably find something useful very quickly.

I assume you are referring to String.equalsIgnoreCase(). That was my first thought as well until I re-read the OP. a and a1 are Arraylists containing Strings, not Strings. Sorry if I'm wrong about your assumption, but I couldn't see anything in the String API that would help here.

My second thought was to check the Collections class to see if it had an equals or compare method that took a Comparator as a parameter, but I couldn't see anything. Maybe satya could write such a method.

[David Newton]

There's a sort that takes a comparator.

[Campbell Ritchie]

I meant both equalsIgnoreCase and the built-in Comparator in the String class, Joanne; you need that Comparator, otherwise it will sort "ONE" "THREE" "two". As you say, you would have to write your own method using it equalsIgnoreCase.

And yes, just like you, I thought it meant comparing the Strings. Sorry.

[Campbell Ritchie]

Campbell Ritchie wrote: . . . "ONE" "THREE" "two". . .

Or "ONE" "TWO" "three" depending on the inputs. Please google for ASCIIbetical order, Satya.