Programming Questions and Answers in C++ and Java for Freshers

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💻 Programming Questions and Answers in C++ and Java for Freshers

🌟 Introduction

When you start preparing for a programming interview, you’ll often face practical coding questions that test your logic, syntax understanding, and problem-solving skills.
In this guide, you’ll learn some common programming questions in both C++ and Java, written in an easy-to-understand way.

Each question includes:

• A brief explanation
• A sample program
• And a clear output

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🧩 Part 1: C++ Programming Questions and Answers

1. Write a program to check whether a number is even or odd.

Explanation:
If a number is divisible by 2, it is even; otherwise, it’s odd.

#include <iostream>
using namespace std;

int main() {
    int num;
    cout << "Enter a number: ";
    cin >> num;
    
    if (num % 2 == 0)
        cout << num << " is Even.";
    else
        cout << num << " is Odd.";
    
    return 0;
}

Output:

Enter a number: 5  
5 is Odd.

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2. Find the sum of first N natural numbers.

Logic:
Sum = n*(n+1)/2

#include <iostream>
using namespace std;

int main() {
    int n, sum = 0;
    cout << "Enter n: ";
    cin >> n;
    
    for(int i = 1; i <= n; i++) {
        sum += i;
    }
    cout << "Sum = " << sum;
    return 0;
}

Output:

Enter n: 5  
Sum = 15

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3. Check if a number is Prime.

Explanation:
A prime number is divisible only by 1 and itself.

#include <iostream>
using namespace std;

int main() {
    int num, flag = 0;
    cout << "Enter number: ";
    cin >> num;

    if (num <= 1) flag = 1;

    for (int i = 2; i <= num / 2; i++) {
        if (num % i == 0) {
            flag = 1;
            break;
        }
    }

    if (flag == 0)
        cout << num << " is Prime.";
    else
        cout << num << " is not Prime.";

    return 0;
}

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4. Reverse a string without using library function.

#include <iostream>
#include <string>
using namespace std;

int main() {
    string str;
    cout << "Enter a string: ";
    cin >> str;

    for (int i = str.length() - 1; i >= 0; i--) {
        cout << str[i];
    }
    return 0;
}

Example:
Input: Hello
Output: olleH

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5. Swap two numbers without using a third variable.

#include <iostream>
using namespace std;

int main() {
    int a, b;
    cout << "Enter two numbers: ";
    cin >> a >> b;

    a = a + b;
    b = a - b;
    a = a - b;

    cout << "After swapping: a = " << a << ", b = " << b;
    return 0;
}

Output:

Enter two numbers: 5 10  
After swapping: a = 10, b = 5

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6. Find factorial of a number using recursion.

#include <iostream>
using namespace std;

int factorial(int n) {
    if (n == 0)
        return 1;
    else
        return n * factorial(n - 1);
}

int main() {
    int n;
    cout << "Enter a number: ";
    cin >> n;
    cout << "Factorial of " << n << " = " << factorial(n);
    return 0;
}

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7. Print Fibonacci Series up to n terms.

#include <iostream>
using namespace std;

int main() {
    int n, a = 0, b = 1, next;
    cout << "Enter number of terms: ";
    cin >> n;
    cout << "Fibonacci Series: ";

    for (int i = 1; i <= n; i++) {
        cout << a << " ";
        next = a + b;
        a = b;
        b = next;
    }
    return 0;
}

Output:

Enter number of terms: 6  
Fibonacci Series: 0 1 1 2 3 5

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☕ Part 2: Java Programming Questions and Answers

1. Check if a number is even or odd.

import java.util.Scanner;

public class EvenOdd {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a number: ");
        int num = sc.nextInt();

        if (num % 2 == 0)
            System.out.println(num + " is Even.");
        else
            System.out.println(num + " is Odd.");
    }
}

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2. Find the factorial of a number.

import java.util.Scanner;

public class Factorial {
    static int fact(int n) {
        if (n == 0)
            return 1;
        else
            return n * fact(n - 1);
    }

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a number: ");
        int n = sc.nextInt();
        System.out.println("Factorial = " + fact(n));
    }
}

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3. Reverse a string without using built-in functions.

import java.util.Scanner;

public class ReverseString {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a string: ");
        String str = sc.next();
        String rev = "";

        for (int i = str.length() - 1; i >= 0; i--) {
            rev += str.charAt(i);
        }

        System.out.println("Reversed string: " + rev);
    }
}

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4. Check if a number is Prime.

import java.util.Scanner;

public class PrimeCheck {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a number: ");
        int num = sc.nextInt();
        boolean flag = false;

        for (int i = 2; i <= num / 2; i++) {
            if (num % i == 0) {
                flag = true;
                break;
            }
        }

        if (!flag)
            System.out.println(num + " is Prime.");
        else
            System.out.println(num + " is not Prime.");
    }
}

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5. Print Fibonacci Series.

import java.util.Scanner;

public class Fibonacci {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter number of terms: ");
        int n = sc.nextInt();

        int a = 0, b = 1, next;
        System.out.print("Fibonacci Series: ");

        for (int i = 1; i <= n; i++) {
            System.out.print(a + " ");
            next = a + b;
            a = b;
            b = next;
        }
    }
}

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6. Swap two numbers without using third variable.

import java.util.Scanner;

public class SwapNumbers {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter two numbers: ");
        int a = sc.nextInt();
        int b = sc.nextInt();

        a = a + b;
        b = a - b;
        a = a - b;

        System.out.println("After swapping: a = " + a + ", b = " + b);
    }
}

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7. Check Palindrome String.

import java.util.Scanner;

public class Palindrome {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a word: ");
        String str = sc.next();
        String rev = "";

        for (int i = str.length() - 1; i >= 0; i--) {
            rev += str.charAt(i);
        }

        if (str.equals(rev))
            System.out.println("Palindrome!");
        else
            System.out.println("Not Palindrome!");
    }
}

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🧠 Bonus Tips for Freshers

• Always understand the logic before coding.
• Practice using loops, conditionals, and arrays.
• Revise OOP concepts like inheritance and polymorphism.
• Don’t memorize code — focus on how it works.
• Practice in both C++ and Java since logic remains same, only syntax changes.

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🏁 Conclusion

These are some of the most commonly asked C++ and Java programming questions for freshers.
Each program here is simple, unique, and easy to understand.
If you master these basics, you’ll be ready for any beginner-level coding interview with confidence.