Frequency of Characters in Array

This program calculates frequency of characters in a character array.

Problem Statement

Write a Java program to count frequency of each character in a character array.

Source Code

1 import java.util.HashMap;
2 public class CharacterFrequency {
3 public static void main(String[] args) {
4 System.out.println("Eduinq Character Frequency");
5 char[] arr = {'a','b','a','c','b','a'};
6 HashMap<Character,Integer> freq = new HashMap<>();
7 for(char ch:arr){
8 freq.put(ch,freq.getOrDefault(ch,0)+1);
9 }
10 for(char key:freq.keySet()){
11 System.out.println("Character "+key+" occurs "+freq.get(key)+" times");
12 }
13 }
14 }

Program Output

Eduinq Character Frequency
Character a occurs 3 times
Character b occurs 2 times
Character c occurs 1 times

Explanation

A HashMap keyed by character stores each character's frequency, updated as the array is traversed, and a second loop prints the character frequencies, demonstrating frequency analysis on a character array.

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