Given a string and a character, the task is to make a function which counts the occurrence of the given character in the string using Stream API.
Examples:
Input: str = "neveropen", c = 'e' Output: 4 'e' appears four times in str. Input: str = "abccdefgaa", c = 'a' Output: 3 'a' appears three times in str.
Approach:
- Convert the string into character stream
- Check if the character in the stream is the character to be counted using filter() function.
- Count the matched characters using the count() function
Below is the implementation of the above approach:
// Java program to count occurrences// of a character using Stream  import java.util.stream.*;  class GFG {      // Method that returns the count of the given    // character in the string    public static long count(String s, char ch)    {          return s.chars()            .filter(c -> c == ch)            .count();    }      // Driver method    public static void main(String args[])    {        String str = "neveropen";        char c = 'e';        System.out.println(count(str, c));    }} |
Output:
4
Related Article: Program to count occurrence of a given character in a string
