Question

Hi I need some help on this lab. The world depends on its successfull compilation.

/*

Lab5.java Arrays, File input and methods

Read the comments and insert your code where indicated.

Do not add/modify any output statements

*/

import java.io.*;

import java.util.*;

public class Lab5

{

public static void main (String[] args) throws Exception

{

final int ARRAY_MAX = 30;

// "args" is the list of tokens you put after "java Project3" on command line

if (args.length == 0 ) // i.e If you did not type anything after "java Project4" on command line

{

System.out.println("FATAL ERROR: Must type a filename on cmd line\n" +

"Like this -> C:\\Users\\tim\\Desktop>java Project4 P4input.txt");

System.exit(0); //ABORT program. Make user try again with a filename this time.

}

Scanner infile = new Scanner( new File(args[0]) );

int[] array = new int[ARRAY_MAX];

int count=0;

while ( infile.hasNextInt() )

array[count++] = infile.nextInt(); // POST increment NOT pre. Do you see why?

System.out.println( "array capacity: " + array.length + "\narray count: " + count);

printArray( array, count ); // ECHO ALL (count) ELEMENTS ON ONE LINE

System.out.println("The sum of the numbers in array is: " + calcSum( array, count ) );

System.out.println("The INDEX of the minimum value in array is: " + indOfMin( array, count ) );

System.out.println("The minimum value in array is: " + minVal( array, count ) );

System.out.println("The INDEX of the maximum value in array is: " + indOfMax( array, count ) );

System.out.println("The maximum value in array is: " + maxVal( array, count ) );

System.out.format("The average of the numbers in array is: %.2f\n", calcAverage( array, count ) );

} // END main

// GIVEN AS IS: DO MOT MODIFY Or DELETE

private static void printArray( int[] a, int cnt )

{

System.out.print( "array elements: ");

for ( int i=0 ; i<cnt ;i++)

System.out.print( a[i] + " " );

System.out.println();

}

// #############################################################################################

// JUST LIKE IN LAB5. YOU MUST WRITE THE DEFINTIONS OF THE METHODS ABOVE THAT ARE CALLED IN MAIN

// #############################################################################################

// CALCSUM: (I'LL GIVE YOU THE TEMPLATE OF THE FIRST METHOD TO FOLLOW FOR THE REST)

private static int calcSum( int[] arr, int cnt)

{

int sum=0; // declare a var to hold the running total as you add each one increment

// HERE: write a for loop on i that adds each a[i] into sum

return sum; // DONE;

}

// INDOFMIN: You must examine each element and return index position

// of the smallest number in the array

// MINVAL: TRY TO RE-USE indOfMin in your calculation

// If you do then this whole method is 1 liner return statement

// and you don't need any loops ;)

// INDOFMAX: You must examine each element and return index position

// of the largest number in the array

// MAXVAL: TRY TO RE-USE indOfMax in your calculation

// If you do then this whole method is 1 liner return statement

// and you don't need any loops ;)

// CALCAVERAGE: TRY TO RE-USE calcSum in your calculation

// If you do then this whole method is 1 liner return statement

// and you don't need any loops ;)

} //END OF LAB5 CLASS

Answer 1

Given below is the code for the question. You will need to pass the name of the input file to the program. Otherwise it will generate error.
Let me know if you have any issues. Please use the input file P4input.txt provided by your instructor.
To indent code in eclipse , select code by pressing ctrl+a and then indent using ctrl+i
Please do rate the answer if it was helpful. Thank you


/*
Lab4.java Arrays, File input and methods
Read the comments and insert your code where indicated.
Do not add/modify any output statements
*/
import java.io.*;
import java.util.*;
public class Lab4
{
public static void main (String[] args) throws Exception
{
final int ARRAY_MAX = 30;
// "args" is the list of tokens you put after "java Project3" on command line
if (args.length == 0 ) // i.e If you did not type anything after "java Project4" on command line
{
System.out.println("FATAL ERROR: Must type a filename on cmd line\n" +
"Like this -> C:\\Users\\tim\\Desktop>java Project4 P4input.txt");
System.exit(0); //ABORT program. Make user try again with a filename this time.
}
Scanner infile = new Scanner( new File(args[0]) );
int[] array = new int[ARRAY_MAX];
int count=0;
while ( infile.hasNextInt() )
array[count++] = infile.nextInt(); // POST increment NOT pre. Do you see why?
System.out.println( "array capacity: " + array.length + "\narray count: " + count);
printArray( array, count ); // ECHO ALL (count) ELEMENTS ON ONE LINE
System.out.println("The sum of the numbers in array is: " + calcSum( array, count ) );
System.out.println("The INDEX of the minimum value in array is: " + indOfMin( array, count ) );
System.out.println("The minimum value in array is: " + minVal( array, count ) );
System.out.println("The INDEX of the maximum value in array is: " + indOfMax( array, count ) );
System.out.println("The maximum value in array is: " + maxVal( array, count ) );
System.out.format("The average of the numbers in array is: %.2f\n", calcAverage( array, count ) );
} // END main
// GIVEN AS IS: DO MOT MODIFY Or DELETE
private static void printArray( int[] a, int cnt )
{
System.out.print( "array elements: ");
for ( int i=0 ; i<cnt ;i++)
System.out.print( a[i] + " " );
System.out.println();
}
// #############################################################################################
// JUST LIKE IN LAB5. YOU MUST WRITE THE DEFINTIONS OF THE METHODS ABOVE THAT ARE CALLED IN MAIN
// #############################################################################################
// CALCSUM: (I'LL GIVE YOU THE TEMPLATE OF THE FIRST METHOD TO FOLLOW FOR THE REST)
private static int calcSum( int[] arr, int cnt)
{
int sum=0; // declare a var to hold the running total as you add each one increment
// HERE: write a for loop on i that adds each a[i] into sum
for(int i = 0; i < cnt; i++)
sum += arr[i];
return sum; // DONE;
}
// INDOFMIN: You must examine each element and return index position
// of the smallest number in the array
private static int indOfMin( int[] arr, int cnt)
{
int minIndex = 0; //assume first element is smallest
for(int i = 1; i < cnt; i++){
if(arr[i] < arr[minIndex])
minIndex = i;
}
return minIndex;
}
// MINVAL: TRY TO RE-USE indOfMin in your calculation
// If you do then this whole method is 1 liner return statement
// and you don't need any loops ;)
private static int minVal( int[] arr, int cnt)
{
return arr[indOfMin(arr,cnt)];
}
// INDOFMAX: You must examine each element and return index position
// of the largest number in the array
private static int indOfMax( int[] arr, int cnt)
{
int maxIndex = 0; //assume first element is greatest
for(int i = 1; i < cnt; i++){
if(arr[i] > arr[maxIndex])
maxIndex = i;
}
return maxIndex;
}
// MAXVAL: TRY TO RE-USE indOfMax in your calculation
// If you do then this whole method is 1 liner return statement
// and you don't need any loops ;)
private static int maxVal( int[] arr, int cnt)
{
return arr[indOfMax(arr,cnt)];
}
// CALCAVERAGE: TRY TO RE-USE calcSum in your calculation
// If you do then this whole method is 1 liner return statement
// and you don't need any loops ;)
private static int calcAverage( int[] arr, int cnt)
{
return calcSum(arr,cnt) / cnt;
}

} //END OF LAB CLASS