How to Count Occurrences of a Character in a String in Java

Learn how to count occurrences of a character in a String in Java using loops. In this tutorial, we will learn how to count the number of times a specific character appears in a string using a simple Java program with an example.

Code Explanation (Step-by-Step)

  • create a method named noOfOccurrenceCharInString().
  • Pass a character and a String as parameters to the method.
  • Initialize a variable count to store the number of occurrences of the given character.
  • Convert the String into a character array using the toCharArray()
  • Traverse all characters of the array using a for loop .
  • Inside the if condition, compare the given character with each character of the array.
  • If both characters are equal, increment the count
  • After traversing the entire array, return the count
  • Now print the count, which represents the number of occurrences of the given character in the String.
				
					public class NoOfGivenDuplicateChar {

    public static void main(String[] args) {

        int count = noOfOccurrenceCharInString('a', "java is a language");

        System.out.println("Number of occurrence of character 'a' is : " + count);
    }

    public static int noOfOccurrenceCharInString(char ch, String str) {

        int count = 0;

        char[] charArray = str.toCharArray();

        for (int i = 0; i < charArray.length; i++) {
            if (ch == charArray[i]) {
                count++;
            }
        }

        return count;
    }
}
`

Output :-
Number of occurrence of character ‘a’ is : 5

Count Occurrences of a Character in a String Using Java 8 Streams

				
					public class CountCharJava8 {

    public static void main(String[] args) {

        String str = "java is a language";
        char ch = 'a';

        long count = str.chars()
                        .filter(c -> c == ch)
                        .count();

        System.out.println("Number of occurrences of 'a' is : " + count);
    }
}

Output :-
Number of occurrence of character ‘a’ is : 5

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