count the number of specific characters in a string java?

There are multiple way to count the number of specific characters in a string java. here we are count the character ‘h’ in the given string.

From toCharArray() and forloop() method:-

Create test method with int return type.
Declare a default count variable.
Convert String to character from str.toCharArray() method and store in ch[] array.
Iterate the character from for loop 0 to ch.length till.
Inside if condition, we compare the given character to character array index value.
If it return true then count and increment.
Now print the number of character value from i.

From java8 map and filter :-

First we convert string to intStream from chars() method.
From mapToObj() method we convert intStream data into Stream<Character>.
Inside filter we compare given character from input character ch value.
Now count the character from count() method.
Print number of character.

				
					public class CountCharDemo {
	public static void main(String[] args) {
		CountCharDemo cd = new CountCharDemo();
		String str = "how are you well here";
		// from toCharArray and for loop method
		int i = cd.test('h', str);
		System.out.println("total number of character from TocharArray :- " + i);

		// from java8 map and filter
		long count = str.chars().mapToObj(x -> (char) x).filter(ch -> ch == 'h').count();
		System.out.println("from java8 map and filter :- " + count);
	}

	public int test(char c, String str) {
		int count = 0;
		char ch[] = str.toCharArray();
		for (int i = 0; i < ch.length; i++) {
			if (c == ch[i]) {
				count++;
			}

		}
		return count;
	}
}

Output :-
total number of character from TocharArray :- 2
from java8 map and filter :- 2