Q: Question 10Write an if statement to find the smallest of the three given integers using the min() method of the Math class.

if (a < Math.min(b, c)) System.out.println(a); else System.out.println(Math.min(b, c));

Question 1

Question 1What is sequential flow of control? Explain with an example.

Accepted Answer

In sequential flow of control, the statements of a program are executed from top to bottom in order in which they are written including method calls. During execution, the control is transferred to the method called. The method is then executed in a sequential order and upon its completion, the control is transferred back to the calling method and execution of statements continues sequentially. For example, the following program will be executed in a sequential manner:public class SequentialExample {
    static void showGreeting() {
        System.out.println("Welcome to KnowledgeBoat");
    }

public static void main(String args[]) {
        System.out.println("Sequential Execution Program Example");
        showGreeting();
    }
}

Question 2

Question 2What is conditional flow of control? Explain with an example.

Accepted Answer

By default, the statements of a program are executed sequentially from top to bottom in order in which they are written. But most of the times our programs require to alter this top to bottom control flow based on some condition. When the flow of control of a program is changed based on some condition using control statements, it is termed conditional flow of control. For example, in the below program we achieve conditional flow of control using the if-else statement.public class ConditionalExample {
    public static void main(String args[]) {
        int x = -10;
        if (x >= 0) {
            System.out.println("Positive Number");
        }
        else {
            System.out.println("Negative Number");
        }
    }
}

Question 3

Question 3Explain the significance of break statement in the switch statement.

Accepted Answer

The break statement is used inside the switch statement to terminate a statement block. It brings the program control out of the switch statement.

Question 4

Question 4What is a fall through? Give an example.

Accepted Answer

break statement at the end of case is optional. Omitting break leads to program execution continuing into the next case and onwards till a break statement is encountered or end of switch is reached. This is termed as fall through. For example, consider the below program:public class FallThroughExample {
    public static void main(String args[]) {
        int number = 1;
        switch(number) {
            case 0:
                System.out.println("Value of number is zero");
            case 1:
                System.out.println("Value of number is one");
            case 2:
                System.out.println("Value of number is two");
            default:
                System.out.println("Value of number is greater than two");
        }
        System.out.println("End of switch");
    }
}Its output when executed will be:Value of number is one
Value of number is two
Value of number is greater than two
End of switch

Question 5

Question 5Explain the significance of the default label in the switch statement.

Accepted Answer

When none of the case values are equal to the expression of switch statement then default case is executed. In the example below, value of number is 4 so case 0, case 1 and case 2 are not equal to number. Hence println statement of default case will get executed printing "Value of number is greater than two" to the console.int number = 4;
switch(number) {
    case 0:
        System.out.println("Value of number is zero");
        break;
    case 1:
        System.out.println("Value of number is one");
        break;
    case 2:
        System.out.println("Value of number is two");
        break;
    default:
        System.out.println("Value of number is greater than two");
        break;
}OutputValue of number is greater than two

Question 6

Question 6Explain the use of System.exit(n) method in Java.

Accepted Answer

The currently running program can be terminated with the help of the exit() method of the System class - System.exit(n). The argument n serves as a status code. A non-zero status code indicates abnormal termination, and a zero status code indicates a normal termination.

Question 7

Question 7Format the following if statements with indentation:i. if (x == y) if (x == z) x = 1; else y = 1; else z = 1;

Accepted Answer

if (x == y)
    if (x == z)
        x = 1; 
    else 
        y = 1;
else
    z = 1;ii. if (x == y) {if (y == z) x = 1; y = 2; } else z = 1;if (x == y)
{
    if (y == z) 
        x = 1; 
    y = 2; 
} 
else 
    z = 1;iii. if (num1 != num2) {    if (num2 >= num3) x = 1; y = 2; }    else {x = 1; if (num1 == num2) z = 3;}if (num1 != num2)
{
    if (num2 >= num3)
        x = 1; 
    y = 2;
}
else
{
    x = 1;
    if (num1 == num2)
        z = 3; 
}

Question 8

Question 8Rewrite the following if statement, using the switch statement:if (choice == 1)
  System.out.println("You selected One");
else if (choice == 2)
  System.out.println("You selected Two");
else if (choice == 3) 
  System.out.println("You selected Three");
else if (choice == 4) 
  System.out.println("You selected Four");
else if (choice == 5) 
  System.out.println("You selected Five");
else if (choice == 6) 
  System.out.println("You selected Six");
else
  System.out.println("Invalid choice");

Accepted Answer

switch (choice) {
  case 1:
    System.out.println("You selected One");
    break;

case 2:
    System.out.println("You selected Two");
    break;

case 3:
    System.out.println("You selected Three");
    break;

case 4:
    System.out.println("You selected Four");
    break;

case 5:
    System.out.println("You selected Five");
    break;

case 6:
    System.out.println("You selected Six");
    break;

default:
    System.out.println("Invalid choice");
}

Question 9

Question 9Write the following switch statement by using nested if statements:switch (choice)
{
case 0:
case 1:
 x = 111;
 y = 222; 
 break;
case 2:
 x = 333;
 y = 444; 
 break;
case 3:
 x = -11;
 y = -22; 
 break;
default:
 y = 555;
}

Accepted Answer

if (choice == 0 || choice == 1)
{
  x = 111;
  y = 222;
}
else
{
  if (choice == 2)
  {
    x = 333;
    y = 444;
  }
  else
  {
    if (choice == 3)
    {
      x = -11;
      y = -22;
    }
    else
    {
      y = 555;
    }
  }
}

Question 10

Question 10Write an if statement to find the smallest of the three given integers using the min() method of the Math class.

Accepted Answer

if (a < Math.min(b, c))
  System.out.println(a);
else
  System.out.println(Math.min(b, c));

Question 11

Question 11Find the error in the given statement:int x = (a => b) ? "a" : "b";

Accepted Answer

=> is an invalid operator. it should be >=Type of x should be String.Corrected StatementString x = (a >= b) ? "a" : "b";

Question 12

Question 12Find the error, if any, in the following code. Write the correct statement.int a=5, b=10;
int x = (a>b)>true:false;

Accepted Answer

Ternary operator is written incorrectly.Type of x should be boolean.Corrected Statementint a=5, b=10;
boolean x = (a>b) ? true:false;

Question 13

Question 13Rewrite the following statement using if else:int max=215, min=323;
String str= (max>min) ? "Max is greater than Min" : "Min is Greater than Max";

Accepted Answer

int max=215, min=323;
String str="";
if (max > min)
  str = "Max is greater than Min";
else
  str = "Min is Greater than Max";

Question 14

Question 14What will be the value of 'n' after the execution of the code given below?int x=2, m=1, c=-1;
int n = x + c;
n = n - c + x;
System.out.println(n);

Accepted Answer

n will be 4 after execution of the code.First n = x + c is executed ⇒ n = 2 + (-1) = 1.Next, n = n - c + x is executed.    n = n - c + x⇒ n = 1 - (-1) + 2⇒ n = 4So final value of n is 4.

Question 15

Question 15What will be the output of the following code?int x=2,y=5,a=0;
a=x; 
x=y; 
y=a; 
System.out.println("x=" + x + " y=" + y);

Accepted Answer

Output is:x=5 y=2This code is swapping the values of x and y.

Question 16

Question 16Find the errors in the following code and rewrite the correct version:char m="A";
Switch ("A");
{
 Case 'a';
     System.out.println("A");
     break;
 Case 'b';
     System.out.println("B");
     break;
 Default:
     System.out.println("Not a valid option");
}

Accepted Answer

The code has the following errors:char variable m is assigned a String literal.S in Switch is capital.There should be no semicolon (;) after switch statement.Expression of switch statement is a String literal "A".C in Case is capital.Semicolon (;) of case statements should be replaced with colon (:).D in Default is capital.Corrected Version:char m = 'A';
switch (m) {
  case 'a':
    System.out.println("A");
    break;
  case 'b':
    System.out.println("B");
    break;
  default:
    System.out.println("Not a valid option");
}

Question 17

Question 17Write a program to find the number of and sum of all integers greater than 500 and less than 1000 that are divisible by 17

Accepted Answer

public class KboatDivisibleBy17
{
    public static void main(String args[]) {
        int sum = 0, count = 0;
        for (int i = 501; i < 1000; i++) {
            if (i % 17 == 0) {
                count++;
                sum += i;
            }    
        }
        System.out.println("Sum = " + sum);
        System.out.println("Count = " + count);
    }
}Output

Question 18

Question 18Create a program to find out if the number entered by the user is a two, three or four digits number.Sample input: 1023Sample output: 1023 is a 4 digit number.

Accepted Answer

import java.util.Scanner; public class KboatNumber { public static void main(String args[]) { Scanner in = new Scanner(System.in); System.out.print("Enter number: "); int n = in.nextInt(); if (n >= 10 && n <= 99) System.out.println("Two Digit Number"); else if (n >= 100 && n <= 999) System.out.println("Three Digit Number"); else if (n >= 1000 && n <= 9999) System.out.println("Four Digit Number"); else System.out.println("Please enter a 2, 3 or 4 digit number"); } }Output

Question 19

Question 19Write a program in Java that reads a word and checks whether it begins with a vowel or not.

Accepted Answer

import java.util.Scanner;

public class KboatWord
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter a word: ");
        String w = in.nextLine();
        char ch = w.charAt(0);
        ch = Character.toUpperCase(ch); 
        if (ch == 'A' ||
            ch == 'E' ||
            ch == 'I' ||
            ch == 'O' ||
            ch == 'U')
            System.out.println("Word begins with a vowel");
        else
            System.out.println("Word does not begin with a vowel");
     }
}Output

Question 20

Question 20Write a program in Java to read three integers and display them in descending order.

Accepted Answer

import java.util.Scanner;

public class KboatDescending
{
    public static void main(String args[]) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter first number: ");
        int a = in.nextInt();
        System.out.print("Enter second number: ");
        int b = in.nextInt();
        System.out.print("Enter third number: ");
        int c = in.nextInt();

int max = -1, mid = -1, min = -1;
        if (a > b) {
            if (a > c) {
                max = a;
                if (b > c) {
                    mid = b;
                    min = c;
                }
                else {
                    mid = c;
                    min = b;
                }
            }
            else {
                max = c;
                mid = a;
                min = b;
            }
        }
        else {
            if (b > c) {
                max = b;
                if (a > c) {
                    mid = a;
                    min = c;
                }
                else {
                    {
                        mid = c;
                        min = a;
                    }
                }
            }
            else {
                max = c;
                mid = b;
                min = a;
            }
        }
        
        System.out.println("Numbers in Descending order:");
        System.out.println(max + " " + mid + " " + min);
    }
}Output

Conditional Constructs in Java