CODEWITHSUNDEEP
javastring
John Quasar
John Quasar

Reputation: 196

My program needs to count the number of occurences of letters in a word, but it seems to count only the occurence of letter 'a'

I need to accept a String and check how many letters of the alphabet appeared on it. However, it seems to only count how many times 'a' appears and concatenate that count to all the letters. I can't find where the error is. Any help will be appreciated. Thanks in advance! Here's my code and output. 

package javaPackage;
public class Counter {
    public static void main(String[] args) {
        String letter="abcdefghijklmnopqrstuvwxyz";
        String word="banana";
        char letterArray[]=letter.toCharArray();
        int length = word.length(); 
        int count = 0;
        int index = 0;
        for (int i=0;i<26;i++) {
        while (index < length) {    
            if (word.charAt(index) == letterArray[i]) {
                count++;        
            }           
            index++;
        }   
        System.out.println("Letter " + letterArray[i]+ " appeared "
                + count+ " times");
    }           
   }    
 }

Output:

Letter a appeared 3 times
Letter b appeared 3 times
Letter c appeared 3 times
Letter d appeared 3 times
Letter e appeared 3 times
Letter f appeared 3 times
Letter g appeared 3 times
Letter h appeared 3 times
Letter i appeared 3 times
Letter j appeared 3 times
Letter k appeared 3 times
Letter l appeared 3 times
Letter m appeared 3 times
Letter n appeared 3 times
Letter o appeared 3 times
Letter p appeared 3 times
Letter q appeared 3 times
Letter r appeared 3 times
Letter s appeared 3 times
Letter t appeared 3 times
Letter u appeared 3 times
Letter v appeared 3 times
Letter w appeared 3 times
Letter x appeared 3 times
Letter y appeared 3 times
Letter z appeared 3 times

Upvotes: 1

Views: 119

Answers (3)

Eran
Eran

Reputation: 393781

You never reset your counter and index variables :

for (int i=0;i<26;i++) {
  index = 0; // added
  counter = 0; // added 
  while (index < length)  {   
      if (word.charAt(index) == letterArray[i]) {   
          count++;        
      }           
      index++;
  }   
}

That said, this implementation is very inefficient. You can count all occurrences in a single for loop.

countArray[0] will count the occurrences of 'a', countArray[1] will count the 'b's, and so on.

String word="banana";
int countArray[]=new int[26];

for (int i = 0; i < word.length(); i++) { 
    countArray[word.charAt(i) - 'a']++;
}  
for (int i = 0; i < countArray; i++) { 
    System.out.println("Letter " + (char)('a' + i) + " appeared " + countArray[i] + " times");
}

Upvotes: 4

LordAnomander
LordAnomander

Reputation: 1123

You have to reset index to 0 once you left the inner loop. Same with count. Otherwise he only runs the inner loop once for the letter A and then never again, because the condition in the while isn't fulfilled.

Edit: efficient solution

int[] letterOccurences = new int[26];
for (int i = 0; i < letterOccurences.length; i++) {
     letterOccurences[i] = 0;
}
for (int i = 0; i < word.length(); i++) {
     letterOccurences[letter.charAt(i) % 97]++; 
     // 'a' % 97 will return 0, 'b' % 97 will return 1 and so on. 
     //Thus, in 0 the count of 'a's, in 1 the count of 'b's and so on will be tracked.
}

Upvotes: 0

RockAndRoll
RockAndRoll

Reputation: 2277

You are not resetting index and count.So it is showing results obtained for a only.

Upvotes: 0

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