LIKELY PRACTICAL QUESTION AND ANSWERS FOR JAVA

 

1.    




Write a Java program to print 'Hello' on screen and then print your name on a separate line. 
Expected Output :
Hello
Alexandra Abramov

 

SOLUTION

public class Exercise1 {

 

 public static void main(String[] args) {

  System.out.println("Hello\nAlexandra Abramov!");

 }

 

}

 

2.    Write a Java program to print the sum of two numbers. 
Test Data:
74 + 36
Expected Output :
110

 

SOLUTION

public class Exercise2 {

 






 public static void main(String[] args) {


  System.out.println(24+26);

 }

 

}

3. Write a Java program to divide two numbers and print on the screen. 
Test Data :
50/3

SOLUTION

public class Exercise3 {

 

 public static void main(String[] args) {

  System.out.println(50/3);

 }

 

}

4. Write a Java program to print the result of the following operations. 
Test Data:
a. -5 + 8 * 6
b. (55+9) % 9
c. 20 + -3*5 / 8
d. 5 + 15 / 3 * 2 - 8 % 3
Expected Output :
43
1
19
13

public class Exercise4 {

 SOLUTION

 public static void main(String[] args) {

  System.out.println(-5 + 8 * 6);

  System.out.println((55+9) % 9);

  System.out.println(20 + -3*5 / 8);

  System.out.println(5 + 15 / 3 * 2 - 8 % 3);

 }

 

}

 

5. Write a Java program that takes two numbers as input and display the product of two numbers. 
Test Data:
Input first number: 25
Input second number: 5
Expected Output :
25 x 5 = 125

SOLUTION

import java.util.Scanner;

 

public class Exercise5 {

 

 public static void main(String[] args) {

  Scanner in = new Scanner(System.in);

  

  System.out.print("Input first number: ");

  int num1 = in.nextInt();

  

  System.out.print("Input second number: ");

  int num2 = in.nextInt();

  

  System.out.println(num1 + " x " + num2 + " = " + num1 * num2);

 }

 

}

 

 

6. Write a Java program to print the sum (addition), multiply, subtract, divide and remainder of two numbers. 
Test Data:
Input first number: 125
Input second number: 24
Expected Output :
125 + 24 = 149
125 - 24 = 101
125 x 24 = 3000
125 / 24 = 5
125 mod 24 = 5

SOLUTION

import java.util.Scanner;

 

public class Exercise6 {

 

 public static void main(String[] args) {

  Scanner in = new Scanner(System.in);

  

  System.out.print("Input first number: ");

  int num1 = in.nextInt();

  

  System.out.print("Input second number: ");

  int num2 = in.nextInt();

  

 

  System.out.println(num1 + " + " + num2 + " = " +

  (num1 + num2));

  

  System.out.println(num1 + " - " + num2 + " = " +

  (num1 - num2));

  

  System.out.println(num1 + " x " + num2 + " = " +

  (num1 * num2));

  

  System.out.println(num1 + " / " + num2 + " = " +

  (num1 / num2));

 

  System.out.println(num1 + " mod " + num2 + " = " +

  (num1 % num2));

 }

 

}

 

 

7. Write a Java program that takes a number as input and prints its multiplication table upto 10. 
Test Data:
Input a number: 8
Expected Output :
8 x 1 = 8
8 x 2 = 16
8 x 3 = 24
...
8 x 10 = 80

 

SOLUTION

 

import java.util.Scanner;

 

public class Exercise7 {

 

 public static void main(String[] args) {

  Scanner in = new Scanner(System.in);

  

  System.out.print("Input a number: ");

  int num1 = in.nextInt();

  

  for (int i=0; i< 10; i++){

   System.out.println(num1 + " x " + (i+1) + " = " +

     (num1 * (i+1)));

  }

 }

}

 

Copy

 

8. Write a Java program to display the following pattern.
Sample Pattern :

   J    a   v     v  a                                                 

   J   a a   v   v  a a                                                

J  J  aaaaa   V V  aaaaa                                                

 JJ  a     a   V  a     a

 

SOLUTION

public class Exercise8 {

 

    public static void main(String[] args) {

 

        System.out.println("   J    a   v     v  a ");

        System.out.println("   J   a a   v   v  a a");

        System.out.println("J  J  aaaaa   V V  aaaaa");

        System.out.println(" JJ  a     a   V  a     a");

    }

}

 

 

 

9. Write a Java program to compute the specified expressions and print the output.  Test Data:
((25.5 * 3.5 - 3.5 * 3.5) / (40.5 - 4.5))
Expected Output
2.138888888888889

SOLUTION

public class Exercise9 {

 

    public static void main(String[] arg) {

 

        System.out.println((25.5 * 3.5 - 3.5 * 3.5) / (40.5 - 4.5));

    }

}

 

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10. Write a Java program to compute a specified formula.  Specified Formula :
4.0 * (1 - (1.0/3) + (1.0/5) - (1.0/7) + (1.0/9) - (1.0/11))
Expected Output
2.9760461760461765

SOLUTION

public class Exercise10 {

    public static void main(String[] args) {

        double result = 4.0 * (1 - (1.0/3) + (1.0/5) - (1.0/7) + (1.0/9) - (1.0/11));

        System.out.println(result); //

    }

}

 

11. Write a Java program than read an integer and calculate the sum of its digits and write the number of each digit of the sum in English

 

SOLUTION

import java.io.*;

 

public class Main {

         public static void main(String[] args) {

                 BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

                

                 try {

                          int sum = 0;

                          String str = br.readLine();

                          char[] numStr = str.toCharArray();

                          for (int i = 0; i < numStr.length; i ++) {

                                  sum += numStr[i] - '0';

                          }

                          System.out.println("Original Number: "+str);

                          print_number(sum);

                 } catch (IOException e) {

                          e.printStackTrace();

                 }

         }

        

         public static void print_number(int n) {

                 int x; int y; int z;

                 String[] number = {"zero","one","two","three","four","five","six","seven","eight","nine"};

                 System.out.println("Sum of the digits of the said number: "+n);

                 if (n < 10) {

                          System.out.println(number[n]);

                 }

                 else if (n < 100) {

                          x = n / 10;

                          y = n - x *10;

                          System.out.println("In English: "+number[x] + " " + number[y]);

                 }

                 else {

                          x = n / 100;

                          y = (n - x * 100) / 10;

                          z = n - x * 100 - y * 10;

                          System.out.println("In English: "+number[x] + " " + number[y] + " " + number[z]);

                 }

                

         }

12. Write a Java program to check whether a security manager has already been established for the current application or not.

import java.lang.*;

 public class Exercise89 {

 public static void main(String[] args)

 {

         System.out.println("System security interface:");

    System.out.println(System.getSecurityManager());   

  }

}

13. Write a Java program to check whether a security manager has already been established for the current application or not.

SOLUTION

import java.lang.*;

 public class Exercise89 {

 public static void main(String[] args)

 {

         System.out.println("System security interface:");

    System.out.println(System.getSecurityManager());   

  }

}

14. Write a Java program to get the first occurrence (Position starts from 0.) of an element of a given array.

SOLUTION

import java.util.Scanner;

public class Main {

public static void main(String[] args) {

    int nums[] = {2, 4, 6, 7, 8};

    int target = 7;

        int lower = 0;

        int upper = nums.length - 1;

        int index = -1;

        while (lower <= upper) {

            int mid = (lower + upper) >> 1;

            if (nums[mid] == target) {

                index = mid;

            }

            if (nums[mid] >= target) {

                upper = mid - 1;

            } else {

                lower = mid + 1;

            }

        }

        System.out.print("Position of "+target +" is "+index);

    }

}

15. Write a Java program to find the index of the first unique character in a given string, assume that there is at least one unique character in the string. Go to the editor

Sample Output:

Original String: wresource

First unique character of the above: 0

SOLUTION

import java.util.*;

public  class  Solution {

    public static void main(String[] args) {

                 String s = "wresource";

                 System.out.println("Original String: "+s);

        System.out.println("First unique character of the above: "+first_Uniq_Char(s));

    }

 

    public static int first_Uniq_Char(String s) {

         int[] freq = new int[256];

        for (char c : s.toCharArray()) {

            freq[c - 'a']++;

        }

        for (int i = 0; i < s.length(); i++) {

            if (freq[s.charAt(i) - 'a'] == 1) return i;

        }

        return -1;

         }

 }

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