logo codesdope
Level 1
1.
Take 10 integers from keyboard using loop and print their average value on the screen.
Answer
import java.util.Scanner;
class Ans{
  public static void main(String[] args){
    Scanner s = new Scanner(System.in);
    int sum = 0;
    for(int i = 0; i<10;i++){
      System.out.println("Enter a number");
      sum = sum+s.nextInt();
    }
    System.out.println("Sum is "+sum);
  }
}
									

2.
Print the following patterns using loop :
a.
*
**
***
****
b.
   *  
 *** 
*****
 *** 
   *  
c.
1010101
 10101 
  101  
   1   

3.
Print multiplication table of 24, 50 and 29 using loop.
Answer
class Ans{
  public static void main(String[] args){
    for(int i = 1; i<=10;i++){
      System.out.println("12 * "+i+"\t=\t"+(12*i));
    }
  }
}
									

4.
Print ASCII values and their equivalent characters. ASCII value vary from 0 to 255.

5.
Factorial of any number n is represented by n! and is equal to 1*2*3*....*(n-1)*n. E.g.-
4! = 1*2*3*4 = 24
3! = 3*2*1 = 6
2! = 2*1 = 2
Also,
1! = 1
0! = 0
Write a Java program to calculate factorial of a number.
Answer
import java.util.Scanner;
class Ans{
  public static void main(String[] args){
    Scanner s = new Scanner(System.in);
    System.out.println("Enter a number");
    int x = s.nextInt();
    int fact  =  1;
    for(int i = x; i>=1 ;i--){
      fact = fact*i;
    }
    System.out.println("Factorial is "+fact);
  }
}
									

6.
Write a program to find greatest common divisor (GCD) or highest common factor (HCF) of given two numbers.

7.
Take integer inputs from user until he/she presses q ( Ask to press q to quit after every integer input ). Print average and product of all numbers.
Answer
import java.util.*;

class Ans{
public static void main(String[] args) {

String choice = "";

int sum = 0;
int product = 1;
int count = 0;
Scanner input = new Scanner(System.in);

while(!choice.equals("q")){
    System.out.println("Enter a number or q to quit");
    choice = input.next();

    if(!choice.equals("q")){
        int number = Integer.parseInt(choice);
        sum = sum+number;
        product = product*number;
        count++;
    }
} 

System.out.println("Product is: "+product+"\nAverage is: "+((float)sum/count));

}
}
									

8.
Write an infinite loop.
A inifinte loop never ends. Condition is always true.
Level 2
1.
Take as input a fraction in the form a/b. Convert the same into lowest terms and print. (Lowest terms examples 3/12 = 1/4).
Answer
import java.util.*;

class Ans{
  public static void main(String[] args) {

    int num;
    int den;

    Scanner input = new Scanner(System.in);

    System.out.println("Enter numerator");
    num = input.nextInt();
    System.out.println("Enter denominator");
    den = input.nextInt();

    //calculating HCF
    int a,b,gcd,t;
    if(num>den){
      a = num;
      b = den;
    }
    else{
      b = num;
      a = den;
    }
    while (b != 0){
      t = b;
      b = a % b;
      a = t;
    }
    gcd = a;

    System.out.println("In lowest form = "+num/gcd+"/"+den/gcd);
  }
}
									

2.
Calculate the sum of digits of a number given by user. E.g.-
INUPT : 123        OUPUT : 6
INUPT : 12345        OUPUT : 15

3.
A three digit number is called Armstrong number if sum of cube of its digit is equal to number itself.
E.g.- 153 is an Armstrong number because (13)+(53)+(33) = 153.
Write all Armstrong numbers between 100 to 500.
Answer
class Ans{
  public static void main(String[] args) {
    for(int i=1;i<=500;i++){
      int sum = 0;
      int t = i;
      while(t!=0){
        sum = sum+((t%10)*(t%10)*(t%10));
        t = t/10;
      }
      if(sum==i){
        System.out.println(i);
      }
    }
  }
}
									

4.
Write a program to print all prime number in between 1 to 100.

5.
Write a program to find prime factor of a number.
If a factor of a number is prime number then it is its prime factor.
Answer
import java.util.*;

class Ans{
  public static void main(String[] args) {

    Scanner input = new Scanner(System.in);

    int x;

    System.out.println("Enter the number");
    x = input.nextInt();

    System.out.println("Prime factors of "+x+" are:");

    for(int i=2;i<=x;i++){
      //checking for factor
      if(x%i==0){
        //checking if i is prime or not
        int p = 0;
        for(int j=2;j<i;j++){
          if(i%j==0){
            //i is not prime
            p++;
            break;
          }
        }
        if(p==0){
          //if p is 0
          //then i is prime
          System.out.println(i);
        }
      }
    }
  }
}
									

6.
Write a program in java to find the sum of the even and odd digits of the number which is given as input.
Doubt? Ask question
Close

Welcome.please sign up.

Close

Welcome.please login.