using indexOf to count the number of times a letter occurrs?

[evilmonkey]

Is there a way to use index of in java to pull the number of occurrences of every letter in a user defined sentence? I can brute force this but is there a faster more elegant way to achieve the same result. I've started to try this but not sure I am on the right track. any help or push in the right direction would be appreciated.

import java.util.StringTokenizer;
import java.util.Scanner;
 
 
public class Main {
 
 public static void main(String[] args) {
 
 
  System.out.println("Enter the sentence :");
 
  alphaCount alpha =new alphaCount(); 
  Scanner input = new Scanner(System.in);
  String output = "";
  String sentence = input.nextLine();
  StringTokenizer token = new StringTokenizer (sentence );
 
  //String[] words = sentence.split(" "); 
  System.out.println("Number of A's is :"+sentence.indexOf('a'));
  //System.out.println("Number of B's is :"+alpha.numOfBs(sentence));
 }
 
}
 
public class alphaCount {
 
 
    /** Creates a new instance of alphaCount */
    public alphaCount() {
    }
 
  // I could brute force each letter of the alphabet like this 
 public static int numOfAs(String str) {
 int numA = 0;
 
  for(int i = 0;i < str.length();i++) {
   if(str.charAt(i) == 'a') {
    numA++;
   }
 
  }
  return numA;
 }
 
 public static int numOfBs(String str) {
  int numB =0;
 
  for(int i = 0;i < str.length();i++) {
   if(str.charAt(i) == 'b') {
    numB++;
   }
 
  }
  return numB;
 }
 
 
    }

[Ganon11]

You could define a method, numOfChars, that takes a character as its parameter and returns the amount of that character in the string. Thus, you could use sentence.numOfChars('a'); to find the number of a's, sentence.numOfChars('G'); for G's, and so on.

[r035198x]

Is there a way to use index of in java to pull the number of occurrences of every letter in a user defined sentence? I can brute force this but is there a faster more elegant way to achieve the same result. I've started to try this but not sure I am on the right track. any help or push in the right direction would be appreciated.

import java.util.StringTokenizer;
import java.util.Scanner;
 
 
public class Main {
 
public static void main(String[] args) {
 
 
System.out.println("Enter the sentence :");
 
alphaCount alpha =new alphaCount(); 
Scanner input = new Scanner(System.in);
String output = "";
String sentence = input.nextLine();
StringTokenizer token = new StringTokenizer (sentence );
 
//String[] words = sentence.split(" "); 
System.out.println("Number of A's is :"+sentence.indexOf('a'));
//System.out.println("Number of B's is :"+alpha.numOfBs(sentence));
}
 
}
 
public class alphaCount {
 
 
/** Creates a new instance of alphaCount */
public alphaCount() {
}
 
// I could brute force each letter of the alphabet like this 
public static int numOfAs(String str) {
int numA = 0;
 
for(int i = 0;i < str.length();i++) {
if(str.charAt(i) == 'a') {
    numA++;
}
 
}
return numA;
}
 
public static int numOfBs(String str) {
int numB =0;
 
for(int i = 0;i < str.length();i++) {
if(str.charAt(i) == 'b') {
    numB++;
}
 
}
return numB;
}
 
 
}

Might want to have a read at regular expressions as well.

[bloid]

Did you mean something like:

String str = "Hello there!!" ;
char ch = 'e' ;
int count = 0 ;
int pos = -1 ;
while( ( pos = str.indexOf( ch, pos + 1 ) ) > -1 ) count++ ;
System.out.println( "The character " + ch + " occurs " + count + " times" ) ;

?

[evilmonkey]

Did you mean something like:

String str = "Hello there!!" ;
char ch = 'e' ;
int count = 0 ;
int pos = -1 ;
while( ( pos = str.indexOf( ch, pos + 1 ) ) > -1 ) count++ ;
System.out.println( "The character " + ch + " occurs " + count + " times" ) ;

?

Yes I did, but I actually figured it out and it is working, that was close to what I got.
thank you for the reply