Question

write a complete Java program with comments in main and in each method. Data: The input data for this program is given as two columns of numbers. All data will be entered from a fle named input.txt and all output will go to the screen Assume there will not be more than 100 7 23.56 16 88.12 10 75.1 Design a Java class with a main method that does the following 1) Reads the data into two arrays of doubles, arrl and arr2, by invoking the method readData. arrays as parameters. The retum value from readData should be stored in an integer variable num all of the values in the arr2 array by invoking the method changeArray, passing by invoking the method sortArray wice - once for arri 4) Prints the values in both arrays to the screen in two columns as shown below with a header and both arrays and num as parameters 3) Sort arrl and arr2 separately and once for arr2 the numbers right aligned arrl arr2 7.00 164.92 10.00 751.00 16.00 1409.92 The readData method reads two doubles values from the input file. The first value of each line is stored in arrOne, and the second value is stored in arrTwo. For example, in the Sample Data above, 7 would go into arrOne[0] and 23.56 would go into arrTwo[0]. This is repeated until there are no more values in the file. Parameters: arrOne- an array of doubles for storing the 1st value read in per row arrTwo-an array of doubles for storing the 2nd value read in per row Returns: num - an integer representing the number of rows that were read in The changeArray method has parameters: alpha -an array of doubles beta -an array of doubles k - an integer representing the number of elements in alpha and beta to be processed The method multiplles each element of beta by the corresponding value of alpha and stores the result into beta. For example, beta[0],7, is multiplied by alpha [0], 23.56 and the result 164.92, is stored in beta [O] The sortArray method sorts the first k elements of the parameter array into ascending order Parameters: arrToOrder- an array of doubles to be sorted k - an integer representing the number of elements in the array arrToOrder

Answer 1

import java.util.Scanner; //for Scanner class
import java.io.*; //for FileReader and IOException class
class TestData{ //driver class named TestData
//readData method takes two double arrays and returns integer
public static int readData(double arr1[],double arr2[])throws IOException {
int k=0;
//opens file and creates input stream using Scanner object
Scanner read = new Scanner(new FileReader("input.txt"));
while(read.hasNext()){ //reads until file has data tokens
double arrOne = read.nextDouble(); //reads double value
double arrTwo = read.nextDouble(); //reads double value
//stores into arrays
arr1[k] = arrOne;
arr2[k] = arrTwo;
k += 1; //incrments k value
}
return k; //returns k
}
//changeArray method
public static void changeArray(double alpha[],double beta[],int k){
//traverses through arrays and does the evaluation
for(int i=0;i<k;i++){
beta[i] = beta[i]*alpha[i];
}
}
//sortArray method applies bubble sort on array
public static void sortArray(double arrToOrder[],int k){
for(int i=0;i<k-1;i++){
for(int j=0;j<k-i-1;j++){
if(arrToOrder[j]>arrToOrder[j+1]){
double temp = arrToOrder[j];
arrToOrder[j] = arrToOrder[j+1];
arrToOrder[j+1] = temp;
}
}
}
}
//main method
public static void main(String[] args){
//creates two double arrays of size.
double arr1[] = new double[100];
double arr2[] = new double[100];
  
try{ //try block as readData method may arise FileNotFoundException
int k = readData(arr1,arr2); //calls readData method
changeArray(arr1,arr2,k); //calls changeArray method
sortArray(arr1,k); //calls sortArray method for arr1
sortArray(arr2,k); //calls sortArray method for arr2
//prints the arr values to console
System.out.println(" arr1 arr2");
for(int i=0;i<k;i++){
System.out.printf("%5.2f %5.2f\n",arr1[i],arr2[i]);
}
}catch(Exception e){ //if exception arises then
//message gets printed
System.out.println("Exception arised: input file not found");
}
  
}
}

//input.txt file screenshot

input Notepad File Edit Format View H 7 23.56 16 88.12 10 75.1

//output screenshot

C: \java>java TestData arr1 arr2 7.00 164.92 10.00 751.060 16 . 1409 . 92

//any query, post in the comment section