Chapter 6, Problem 18E

Explanation of Solution

Program code:

Main.java

//import the required packages

import java.io.File;

import java.util.Arrays;

import java.util.Scanner;

//define a class inputStats

public class Main

{

//define the main

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

{

//create the object of File class

File fileName = new File("file.txt");

//create the object of Scanner class to refer the file

Scanner in = new Scanner(fileName);

//call the method plusScores()

plusScores(in);

}

//define a method plusScores()

public static void plusScores(Scanner in)

{

//iterate a while loop

while(in.hasNextLine())

{

//declare two string variables to get the lines

String name = in.nextLine();

String score = in.nextLine();

//declare the integer variables

int n=0;

int p=0;

//iterate a for loop to get the count

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

{

    //if the character is +

    if(score.charAt(i) == '+')

    {

        //increment the value of p by 1

        p++;

    }

    //increment the value of n by n

    n++;

}

//print the percentage

System.out.printf("%s: %.1f%% plus\n", name, 100.0*p/n);

}

}

}

carroll.txt

Kane, Erica

--+-+

Chandler, Adam

++-+

Martin, Jake

+++++++

Dillon, Amanda

++-++-+-

Explanation:

The above snippet of code is used to create a method called “plusScores()” that accepts a Scanner representing an input file containing a series of lines that represent student records...