CODEWITHSUNDEEP
javaarrays
user2423959
user2423959

Reputation: 834

matching a letter with a word

I've the below code.

import java.io.File;
import java.util.ArrayList;
import java.util.Scanner;

public class Dummy {
    public static void main(String args[]) throws Exception {

        String word="hi";
        String[] one={"a","b","c"};
        String[] two={"d","e","f"};
        String[] three={"g","h","i"};
        String[] four={"j","k","l"};
        String[] five={"m","n","o"};
        String[] six={"p","q","r","s"};
        String[] seven={"t","u","v"};
        String[] eight={"w","x","y","z"};

        for(int i=0;i<word.length();i++)
        {
            for(int j=0;j<three.length;j++)
            {
                if(three[j].equals(word.charAt(i)))
                {
                    System.out.println("Matched");
                }
                else
                {
                    System.out.println("err");
                }

            }
        }
    }
}

Here my concept is to match a letter from the string to the array created and here the output is all err(condition stating not matched). please let me know where am i going wrong.

Thanks

Upvotes: 0

Views: 87

Answers (6)

Boss Man
Boss Man

Reputation: 769

Just saying the obvious....sometimes it is helpful to see the actual code. Following is excerpt from java.lang.String

See bold condition in particular. it returns false if instanceof fails!

public boolean equals(Object anObject) {
    if (this == anObject) {
        return true;
    }
    if (**anObject instanceof String**) {
        String anotherString = (String)anObject;
        int n = count;
        if (n == anotherString.count) {
        char v1[] = value;
        char v2[] = anotherString.value;
        int i = offset;
        int j = anotherString.offset;
        while (n-- != 0) {
            if (v1[i++] != v2[j++])
            return false;
        }
        return true;
        }
    }
    return false;
    }

Upvotes: 0

wonhee
wonhee

Reputation: 1661

The element three[j] in for loop is String whereas word.charAt(i) is char.. so equals() against those will be always false.

You should either change it to

if(three[j].equals(String.valueOf(word.charAt(i))))

so that it compares string's actual context, or define arrays (one, two, three.. ) to be char array instead of string array so that you can simply use == for that.

Please check equals() for String, Object, and the others in JavaDoc, and probably you need to check hashCode() as well to fully understand what's equals() means in Java.

Upvotes: 1

Suzon
Suzon

Reputation: 759

Try like this: 

StringBuffer result = new StringBuffer();
for (int i = 0; i < one.length; i++) {
    result.append(one[i]);
}
if (result.toString().equals(word)) {
    System.out.println("Matched");
} else {
    System.out.println("err");
}

Upvotes: 0

Mihai Matei
Mihai Matei

Reputation: 24276

Why don't you use String.indexOf() ?

for(int j=0;j<three.length;j++)
{
     if(word.indexOf(three[j]) == -1)
     {
          System.out.println("err");
     }
     else
     {
          System.out.println("Matched");
     }

}

This way you will enter in a single loop..

Upvotes: 0

Francois R.
Francois R.

Reputation: 76

charAt return a char not a string so it can't be "equals" to a String

Upvotes: 0

Sneftel
Sneftel

Reputation: 41474

You're comparing a single-character string (from your arrays) to a character. Make your arrays of char, not String. (And use == to compare them.)

Upvotes: 3

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