Java Interview Questions

Factorial

Java Copy

            
import java.util.Scanner;
  public class basic{
    public static void main(String[] args){
      System.out.println("Enter your limit : ");
      Scanner in = new Scanner(System.in);
      int n = in.nextInt();
      int f = 1;
        for(int i=1;i<=n;i++){
          f=f*i;
        }
        System.out.println(f);
  }
}
  

Average of given n number

Java Copy

            
import java.util.Scanner;
  public class basic{
    public static void main(String[] args){
      System.out.println("Enter your limit : ");
      Scanner in = new Scanner(System.in);
      int n = in.nextInt();
      int sum = 0,a;
      for(int i=1;i<=n;i++){
        System.out.println("Enter your value "+i+" :");
        a = in.nextInt();
        sum+=a;
      }
      System.out.println(sum/n);
    }
  }
  

Fibonacci Series

Java Copy

            
import java.util.Scanner;
public class basic{
  public static void main(String[] args){
    System.out.println("Enter your limit : ");
    Scanner in = new Scanner(System.in);
    int n = in.nextInt();
    int a = -1,b=1,c;
    for(int i=1;i<=n;i++){
      c=a+b;
      System.out.println(c);
      a=b;
      b=c;
    }
  }
}
  

Reverse of n digit number

Java Copy

            
import java.util.Scanner;
public class basic{
  public static void main(String[] args){
    System.out.println("Enter your value : ");
    Scanner in = new Scanner(System.in);
    int n = in.nextInt();
    int reverse = 0, rem;
    while(n!=0){
      rem=n%10;
      reverse = (reverse*10)+rem;
      n=n/10;
    }
    System.out.println(reverse);
  }
}
  

Armstrong Number

Java Copy

            
              import java.util.Scanner;
public class basic{
  public static void main(String[] args){
    System.out.println("Enter your value : ");
    Scanner in = new Scanner(System.in);
    int number = in.nextInt();
    int temp = number;
    int d1,d2,d3;
    d1 = temp%10;
    temp = temp/10;
    d2 = temp%10;
    temp = temp/10;
    d3 = temp%10;
    temp=temp/10;
    int result = (d1*d1*d1)+(d2*d2*d2)+(d3*d3*d3);
    if(number == result){
      System.out.println(number+" is armstrong number");
    }else{
      System.out.println(number+" is not armstrong number");
    }
  }
}
  

Armstrong Number within 100 - 999

Java Copy

            
public class basic{
  public static void main(String[] args){
    int d1,d2,d3,temp,result;
    for(int i=100; i<+999; i++){
    temp = i;
    d3 = temp%10;
    
    temp = temp/10;
    d2 = temp%10;

    temp = temp/10;
    d1 = temp%10;

    result = (d1*d1*d1)+(d2*d2*d2)+(d3*d3*d3);
             
      if(i == result){
        System.out.println(i+" is armstrong number");
      }
    }
  }
}
  

Find factors

Java Copy

            
import java.util.Scanner;
public class basic{
  public static void main(String[] args){
    Scanner in = new Scanner(System.in);
    System.out.println("Enter your number : ");
    int n = in.nextInt();
      for (int i = 1; i <= n; i++){
        if(n%i==0){
          System.out.println(i);
        }
      }
  }
}
  

Find prime number

Java Copy

          
import java.util.Scanner;
public class basic{
  public static void main(String[] args){
    Scanner in = new Scanner(System.in);
    System.out.println("Enter your number : ");
    int n = in.nextInt();
    int f = 0;

    for (int i = 1; i <= n; i++){
      if(n%i==0){
        f++;
      }
    }

    if(f==2){
      System.out.println(n +" is prime number");
    }else{
      System.out.println(n +" is not prime number");
    }
  }
}

Find the given number is perfect number are not

Java Copy

            
import java.util.Scanner;
public class HelloWorld{
  public static void main(String[] args){
    Scanner in = new Scanner(System.in);
    System.out.println("Enter your number : ");
    int n = in.nextInt();//6
    int sum = 0;
    for (int i = 1; i < n; i++){
      if(n%i==0){
        sum+=i;
        System.out.println(sum);
      }
    }

    if(sum==n){
      System.out.println(n +" is perfect number");
    }else{
      System.out.println(n +" is not perfect number");
    }
  }
}
  

Find the given number is strong number are not

Java Copy

            
import java.util.Scanner;
public class basic{
  public static void main(String[] args){
    int num,orgnum,rem,factorial,sum=0;
    Scanner in = new Scanner(System.in);
    System.out.println("Enter your number : ");
    num = in.nextInt();
    orgnum = num;

    while(num>0){
      rem=num%10;
      factorial = 1;
    for(int i = 1; i<=rem; i++){
      factorial*=i;
    }
      sum+=factorial;
      num=num/10;
    }

    if(sum==orgnum){
      System.out.println(orgnum + " is a strong number");
    }else{
      System.out.println(orgnum + " is not a strong number");
    }
  }
}
  

Write a Java method to compute the future investment value at a given interest rate for a specified number of years. Sample data (Monthly compounded) and Output,

Input the investment amount: 1000, Input the rate of interest: 10, Input number of years: 5

Expected Output:

Java Copy

            
import java.lang.Math;
public class compounded {
  public static void main(String[] args) {
    int investmentAmount = 1000;
    double monthlyInterestRate = 0.00833;
    int years = 1;
    double result = investmentAmount * Math.pow((1 + monthlyInterestRate), years * 12);
    System.out.println(result);
  }
}