Question

LAB5

#1. Method and loop

Write a method integerPower(base, exponent) that returns the value of base^exponent (2 pts).

For example, integerPower(3, 4) returns 81. Assume thatexponent is a positive nonzero integer, and base is an integer. Method integer should use for or while loop to control the calculation. Do not use any Math library methods. Incorporate this method into a program class and invoke this method with different combinations of input values at least 4 times.

Please use printf() method to generate the multiple outputs from the sequence of the method invocations for integerPower(num1, num2). Remark: The placeholder for boolean value is %b.

   System.out.printf("integerPower(%d, %d) returns %b.", 3, 4, integerPower(3, 4));

#2. Method, loop, and random numbers

For each of the following sets of integers, write five statements that will print a number at random from the set (2.5 pts).

   a) 2, 4, 6, 8, 10

   b) 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20

   c) -10, -9, -8, -7, .., 0, 1, 2, ..., 9, 10

   d) 3, 5, 7, 9, 11, 13

   e) 6, 10, 14, 18, 22, 26

Incorporate the statements into the main() method. Please use println or printf statement to generate the multiple outputs from the sequence of the statements.

#3. Method, loop, Scanner tool, and random number

An integer is said to be prime if it is divisible only by 1 and iteself. For example, 2, 3, 5, and 7 are prime, but 4, 6, 8, and 9 are not. Please give the solution to the following sub-questions (3 pts).

   a) Write a method, isPrime(), that determines if a number is prime.

   b) Use this method in the main() that determines whether user input is prime or not. The main() includes a while loop which continuously reads user input until user types-999 as the sentinel value and checks whether the input value is prime. Within the while loop, please print the input value with the result from the isPrime() method.

   c) Unlike the above case, please use Random class to generate random numbers and use 0 as the exit condition of the while loop.

#4. Method, loop, Scanner tool, and random number

Write a method that takes an integer value and prints the number with its digits reversed. For example, given the number 7631, the method prints 1367 (2.5 pts).

Answer 1

Ans :)

import java.util.Random;

import java.util.Scanner;

public class Test9 {

public static void main(String[] args) {

// TODO Auto-generated method stub

Test9 t=new Test9();

System.out.println(t.integerPower(0, 4));

//2. Random numbers

int set1[]={2, 4, 6, 8, 10 };

System.out.println("Set1 Randomly :\n");

for(int i=0;i<set1.length;i++){

System.out.print(set1[new Random().nextInt(set1.length)]+"\t");

}

int set2[]={10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };

System.out.println("\nSet2 Randomly :\n");

for(int i=0;i<set2.length;i++){

System.out.print(set2[new Random().nextInt(set2.length)]+"\t");

}

int set3[]={-10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

System.out.println("\nSet3 Randomly :\n");

for(int i=0;i<set3.length;i++){

System.out.print(set3[new Random().nextInt(set3.length)]+"\t");

}

int set4[]={3, 5, 7, 9, 11, 13 };

System.out.println("\nSet4 Randomly :\n");

for(int i=0;i<set4.length;i++){

System.out.print(set4[new Random().nextInt(set4.length)]+"\t");

}

int set5[]={6, 10, 14, 18, 22, 26 };

System.out.println("\nSet5 Randomly :\n");

for(int i=0;i<set5.length;i++){

System.out.print(set5[new Random().nextInt(set5.length)]+"\t");

}

System.out.println();

//3.(b) to find prime or not

while(true){

System.out.println("Enter a Positive Number and should be 1<:");

Scanner sc=new Scanner(System.in);

int inputNum=sc.nextInt();

if(inputNum==-999)

break;

if(inputNum<0)

System.out.println("The given number negetive :"+inputNum);

else if(inputNum==0)

System.out.println("The given number is zero :"+inputNum);

else if(inputNum==1)

System.out.println("The given number is one(not prime) :"+inputNum);

else

{

String str="is not prime";

if(t.isPrime(inputNum))

str="is prime";

System.out.println("The given number "+str+" :"+inputNum);

}

}

//3.(c) with random numbers to find prime or not

while(true){

// create instance of Random class

Random rand = new Random();

// Generate random integers in range 0 to 99

int rand_int = rand.nextInt(100);

  

if(rand_int==0){

break;

}

  

if(rand_int==1)

System.out.println("The random number is one(not prime) :"+rand_int);

else

{

String str="is not prime";

if(t.isPrime(rand_int))

str="is prime";

System.out.println("The given number "+str+" :"+rand_int);

}

}

System.out.println("Enter a positive Number for reverse:");

Scanner sc=new Scanner(System.in);

int inputNumber=sc.nextInt();

if(inputNumber>0){

System.out.println("The Reverse Number :"+t.reverse(inputNumber));

}

else{

System.out.println("The given number is negetive");

}

}

//1.integerPower()

private long integerPower(int base, int exponent){

long res=0;

if(exponent>=0){

for(int i=0;i<=exponent;i++){

if(i==0){

res=1;

}else{

res=res*base;

}

}

}else{

System.out.println("the exponent value is negative");

}

return res;

}

private boolean isPrime(int num){

boolean status=true;

int temp=0;

for(int i=2;i<=num/2;i++)

{

temp=num%i;

if(temp==0)

{

status=false;

break;

}

}

return status;

}

//4.reverse()

private int reverse(int inputNumber){

int res=0;

int temp=0;

while(inputNumber > 0)

{

temp = inputNumber % 10;

res = res * 10 + temp;

inputNumber = inputNumber / 10;

}

return res;

}

}