Java code to find frequency of each character in a String

Java program to find the frequency of each character in a String.

import java.io.*;
class Frequency
{
static String n;
static int l;
 public static void main(String args[]) throws IOException
 {
 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
 System.out.print("Enter a String : ");
 n = br.readLine();
 l = n.length();
 freq();
 }
 public static void freq()
 {
 int s=0,f=-1;
 for(int i=0;i<l;i++)
 {
  // Find frequecy
  for(int j=0;j<l;j++)
  {
   if(n.charAt(i)==n.charAt(j))
   s++;
  }

  // Check if the letter has occured before
  for(int k=0;k<i;k++)
  {
   if(n.charAt(i)==n.charAt(k))
   f = 1;
  }

  // Print the letter's frequency
  if(f==-1)
   System.out.println(n.charAt(i) +" = " +s);
  s=0;
  f=-1;
 }
 }
}

ALGORITHM:-

1. Start

2. Accept a sentence from the user.

3. Extract a character.

4. Count the no. of times it occurs in the sentence.

5. Print its frequency.

6. Repeat Steps 3 to 6 till all the frequencies are printed.

7. End

OUTPUT:-

Enter a String : reverberate
r  = 3
e  = 4
v  = 1
b  = 1
a  = 1
t  = 1

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