something like equalsIgnoreCase while using indexOf

Question

I am using this code, to get the index of a String in an Array.

int n = Arrays.asList(Names).indexOf(textBox.getText());

The problem here is, if the String in textBox is different in case to its similar String in the Array. It returns -1. How can make it something like equalsIgnoreCase in case of String comparision.

Thank You

SomeJavaGuy · Answer 1 · 2012-12-11T10:34:33.433

3

You can use the Collator class. in Here you can set different levels for your comparison. you can ignore lower and upper cases, and set some specific language charackters. In German for example it can set ß equal to ss.

here´s some documentary: Collator class

Edit : here´s an example Code for you

private int indexOf(String[] original, String search) {
    Collator collator = Collator.getInstance(); 
    collator.setStrength(Collator.SECONDARY);
    for(int i = 0;i<original.length;++i) {
        if(collator.equals(search, original[i]))
            return i;
    }
    return -1;
}

edited Dec 11 '12 at 10:34

answered Dec 11 '12 at 09:48

SomeJavaGuy

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Watch the example, this is what you are looking for i hope – SomeJavaGuy Dec 11 '12 at 10:03
So now i really figured out what you want :D you just have to give the original String, and the String you are looking for in your original to this method, and it reutrn you the index of the search String, or -1 – SomeJavaGuy Dec 11 '12 at 10:18
But this is to get the index of a substring in a given parent string. My need is to get the index of a String from an Array of Strings. without changing the order of Strings in the Array . – Archie.bpgc Dec 11 '12 at 10:28

score 3 · Answer 2 · edited May 23 '17 at 12:00

You can use StringUtils class of Apache commons libraries or this If you don't want to download the library look at the source code for logic to create the method. The stackoverflow link for using StringUtils

If you want to find the index of String from array of strings then there is another library ArrayUtils which has a method indexOf

here's the implementation of indexOf

 public static int indexOf(Object[] array, Object objectToFind, int startIndex) {
        if (array == null) {
            return INDEX_NOT_FOUND;
        }
        if (startIndex < 0) {
            startIndex = 0;
        }
        if (objectToFind == null) {
            for (int i = startIndex; i < array.length; i++) {
                if (array[i] == null) {
                    return i;
                }
            }
        } else {
            for (int i = startIndex; i < array.length; i++) {
                if (objectToFind.equals(array[i])) {
                    return i;
                }
            }
        }
        return INDEX_NOT_FOUND;
    }

since you can see that it uses .equals() I suggest you to

1) create a custom string class

2) add it to the array

3) override the .equals method like this

class StringCustom
{
String string;
//implement getters and setters
public String equals(Object o)
{
return this.getString().equalsIgnoreCase(((String)o).getString());
}
}

But this is to get the index of a substring in a given parent string — Archie.bpgc, Dec 11 '12 at 10:20
My need is to get the index of a String from an Array of Strings. without changing the order of Strings in the Array — Archie.bpgc, Dec 11 '12 at 10:28
@Archie.bpgc : you can use arrayutils class also. but this won't help you with the Ignore case stuff. still searching... — Bhavik Shah, Dec 11 '12 at 10:35
@Archie.bpgc : one solution would be to create a custom String class and override the equals method of it. then use indexOf() of ArrayUtils since the source code uses equals method — Bhavik Shah, Dec 11 '12 at 10:41

score 1 · Accepted Answer · edited Dec 11 '12 at 13:09

1

A different approach where internally make sure ignore case.

public static int indexOfIgnoreCase(String[] strs, String text){

   int n = strs.length;
   for(int i=0;i<n;i++){
       if(strs[i].equalsIgnoreCase(text))
         return i;
   }
   return -1;
}
int n = indexOfIgnoreCase(Names,textBox.getText());

edited Dec 11 '12 at 13:09

Alexander Pavlov

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answered Dec 11 '12 at 09:44

Subhrajyoti Majumder

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Though i change the String in textBox to upper/lower case, i don't know how it is in the given array. – Archie.bpgc Dec 11 '12 at 09:49
Moreover the Strings in the Array are being used as AutoCompletes. So i cannot convert them to upper/lower case(wont look good in dropdown). May be must create a new array with all Strings as lower/upper case. But its not the best approach – Archie.bpgc Dec 11 '12 at 09:52

Nikolay Kuznetsov · Answer 4 · 2012-12-11T10:24:49.313

You can extend ArrayList in this way

    public class StringArrayList extends ArrayList<String> {
        @Override
        public boolean contains(Object o) {
            String paramStr = (String)o;
            for (String s : this) {
                if (paramStr.equalsIgnoreCase(s)) return true;
            }
            return false;
        }

        public int indexOf(Object o) {
            String paramStr = (String)o;
            int index = 0;
            for (String s : this) {
                if (paramStr.equalsIgnoreCase(s)) return index;
                index++;
            }
            return -1;
        }
    }

Eventually :

int n = new StringArrayList(Arrays.asList(Names)).indexOf(textBox.getText());

something like equalsIgnoreCase while using indexOf

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