Count the number of occurrences of a particular digit in a number

Difficulty Level : Basic
Last Updated : 05 May, 2021

Given a number N and a digit D, the task is to count the occurrences of D in N.
Examples:

Input: N = 25, D = 2
Output: 1

Input: N = 100, D = 0
Output: 2

Approach: Take out the digits one by one in N and check if this digit is equal to D. If equal, then increment the count by 1. In the end, print the count.
Below is the implementation of the above approach:

C++

// C++ program to count the number of occurrences
// of a particular digit in a number
 
#include <iostream>
using namespace std;
 
// Function to count the occurrences
// of the digit D in N
long long int countOccurrances(long long int n,
                               int d)
{
    long long int count = 0;
 
    // Loop to find the digits of N
    while (n > 0) {
 
        // check if the digit is D
        count = (n % 10 == d)
                    ? count + 1
                    : count;
        n = n / 10;
    }
 
    // return the count of the
    // occurrences of D in N
    return count;
}
 
// Driver code
int main()
{
 
    int d = 2;
    long long int n = 214215421;
 
    cout << countOccurrances(n, d)
         << endl;
 
    return 0;
}

Java

// Java program to count the number of occurrences
// of a particular digit in a number
import java.util.*;
 
class GFG
{
 
// Function to count the occurrences
// of the digit D in N
static int countOccurrances(int n,
                            int d)
{
    int count = 0;
 
    // Loop to find the digits of N
    while (n > 0)
    {
 
        // check if the digit is D
        count = (n % 10 == d) ?
                    count + 1 : count;
        n = n / 10;
    }
 
    // return the count of the
    // occurrences of D in N
    return count;
}
 
// Driver code
public static void main(String args[])
{
    int d = 2;
    int n = 214215421;
 
    System.out.println(countOccurrances(n, d));
}
}
 
// This code is contributed by Surendra_Gangwar

Python3

# Python3 program to count the
# number of occurrences of a
# particular digit in a number
 
# Function to count the occurrences
# of the digit D in N
def countOccurrances(n, d):
    count = 0
 
    # Loop to find the digits of N
    while (n > 0):
 
        # check if the digit is D
        if(n % 10 == d):
            count = count + 1
  
        n = n // 10
 
    # return the count of the
    # occurrences of D in N
    return count
 
# Driver code
d = 2
n = 214215421
print(countOccurrances(n, d))
 
# This code is contributed by Mohit Kumar

C#

// C# program to count the number
// of occurrences of a particular
// digit in a number
using System;
class GFG
{
 
// Function to count the occurrences
// of the digit D in N
static int countOccurrances(int n,
                            int d)
{
    int count = 0;
 
    // Loop to find the digits of N
    while (n > 0)
    {
 
        // check if the digit is D
        count = (n % 10 == d) ?
                    count + 1 : count;
        n = n / 10;
    }
 
    // return the count of the
    // occurrences of D in N
    return count;
}
 
// Driver code
public static void Main()
{
    int d = 2;
    int n = 214215421;
 
    Console.WriteLine(countOccurrances(n, d));
}
}
 
// This code is contributed by Code_Mech.

Javascript

<script>
 
// Javascript program to count
// the number of occurrences
// of a particular digit in a number
 
// Function to count the occurrences
// of the digit D in N
function countOccurrances(n, d)
{
    let count = 0;
 
    // Loop to find the digits of N
    while (n > 0) {
 
        // check if the digit is D
        count = (n % 10 == d)
                    ? count + 1
                    : count;
        n = parseInt(n / 10);
    }
 
    // return the count of the
    // occurrences of D in N
    return count;
}
 
// Driver code
 
    let d = 2;
    let n = 214215421;
 
    document.write(countOccurrances(n, d));
 
</script>