Java Read GPA and Return the Average

GPAcalc/.classpath

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+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/jre1.8.0_31"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

GPAcalc/.gitignore

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+/bin/

GPAcalc/.project

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+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>GPAcalc</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

GPAcalc/.settings/org.eclipse.jdt.core.prefs

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+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.8

GPAcalc/courses.txt

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+B;CS 106 Introduction to C
+A;CS 466 Introduction to Java
+A;CS 206 Adnanced database
+C;CS 224 Cpmputer Security

GPAcalc/src/gpa/Calculator.java

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+
+package gpa;
+
+/**
+ * @author khalid
+ */
+import java.util.*;
+import java.io.*;
+
+/** -------------------------------------------------- data member ------------------------------------------- */
+
+public class Calculator {
+          private ArrayList <Course> courses;
+          private Course c;                          // to save what we get from the array list
+          private double  GpaAvg;
+          private Scanner in= new Scanner(System.in);// read from keyboard
+          private Scanner input;					 // read from file
+          private PrintWriter output ;               // print to file
+	      private File f;	                    	 // creay a file			
+
+/** ----------------------------------------- constructor function ------------------------------------------ */
+/** 1. To allocate memory the array list 
+	2. To save the infromation that gets from the file in the array list 
+    3. To write what the array list contains back to the file               */
+
+    public Calculator(){                             
+         courses= new ArrayList<Course>();
+
+         try{             //Read from file and save info in the Arraylist 
+             f = new File("courses.txt");
+             if( f.exists()) // if file is exist
+			 {
+
+				 if( f.length() == 0)  // if file is empty to prevent throw an exption
+				 {
+					 System.out.println("Warning: The file is empty");
+				 } 
+				 else // if the file not empty at least has one line
+				 {
+					 input = new Scanner(new FileReader("courses.txt"));
+					 while(input.hasNextLine()){
+						 String line = input.nextLine();
+						 String parts[] = line.split(";");
+
+						 courses.add( new Course (parts[0],parts[1]));
+					 }//end while
+					 input.close();
+				 }// end else
+
+			 }// end if existe
+			 else System.out.println("Error: the courses.txt file is not exist.\nThe program will create courses.txt file");
+
+         } catch (FileNotFoundException e) {e.printStackTrace();}
+
+        try {        // write info from arraylist to the file
+                output = new PrintWriter(f);
+                for (int i=0; i< courses.size(); i++){
+                output.println((Course) courses.get(i));
+            }
+            output.close();
+
+            }catch (IOException ex){ex.printStackTrace();}
+	}
+
+
+    /* function to let the user enter the course and the GPA
+	 public void interCours(){
+        String course;
+        String degree;
+
+        System.out.print("Enter course name: ");
+        course=in.next();
+        do{
+        System.out.print("Enter GPA(A,B,C,F): ");
+        degree= in.nextLine();
+        if (degree.equals("A") ||degree.equals("A") ||degree.equals("b")||degree.equals("B")||degree.equals("C")||degree.equals("c")||degree.equals("f")||degree.equals("F")) break;
+        String junck=in.nextLine();
+        }while (true);
+        courses.add(new Course(degree,course));
+    } */
+
+	/** ------------------------ display Courses And GPA ------------------------- */
+
+    public void displayCourses (){
+        String GPA,cname;
+		if(courses.size()>0){
+			System.out.println("Course name\t\t\t\t GPA");
+            System.out.println("-----------\t\t\t\t ---");
+            for(int i=0; i<courses.size(); i++ ) {
+				Course c= (Course) courses.get(i);
+				GPA=c.getGPA();
+				cname=c.getCourse();
+				System.out.println(cname+"\t\t  "+GPA);
+            }
+		}
+		else {
+			System.out.println("There is no Courses to display ");
+		}
+
+
+    }
+	/** ------------------------ Calculate AVRAGE GPA ------------------------- */
+
+    public void caluclate(){
+        String GPA;
+        int Gpacourse=0;
+        int GpaTotal=0;
+
+
+		//--------------------- start using swich in a loop
+        for(int i=0; i<courses.size(); i++ ) {
+            Course c= (Course) courses.get(i);
+            GPA=c.getGPA();
+			//switch(GPA.trim())
+			switch(GPA.charAt(0))
+			{
+				case 'A': 
+					Gpacourse=4;
+					break;
+				case 'B':
+					Gpacourse=3;
+					break;
+				case 'C':
+					Gpacourse=2;
+					break;
+			    case 'F':
+					Gpacourse=0;
+					break;
+			}
+			GpaTotal+=  Gpacourse;
+        }
+		//--------------------end using wich in a loop
+
+		/* 
+		 //note: other way to calculate the GPA Avarage by using if else.. it works too I tried it but I prefer switch. it is more orgnized and eazy to read
+		 for(int i=0; i<courses.size(); i++ ) {
+		 Course c= (Course) courses.get(i);
+		 GPA=c.getGPA();
+		 if (GPA.equals("A")) Gpacourse=4;
+		 else if (GPA.equals("B")) Gpacourse=3;
+		 else if     (GPA.equals("C")) Gpacourse=2;
+		 else if     (GPA.equals("F")) Gpacourse=0;
+		 GpaTotal+=  Gpacourse;
+		 }*/
+
+        if (courses.size()>0){
+			GpaAvg=(double)GpaTotal /(double)courses.size();
+            System.out.printf("\n** The Average GPA is %.2f **\n ",GpaAvg);
+		}else{
+			GpaAvg=0.0; // to prevent NAN result
+			System.out.printf("** Avarage of the GPA is %.2f**\n ",GpaAvg);
+		} 
+    }
+
+	/** -------------------- Main Function creat new object and call dispaly and calulate function --------------- */
+
+    public static void main(String[] args ){
+
+        try {
+            Calculator objCourse = new  Calculator();
+            objCourse.displayCourses();
+            objCourse.caluclate();
+        } catch (Exception ex) {
+            System.out.println("Error: "+ex);
+            ex.printStackTrace();
+            System.exit(0);
+        }
+
+    }
+}
+

GPAcalc/src/gpa/Course.java

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+package gpa;
+
+
+/**
+ * @author khalid
+ *
+ * Exam Program by khalid
+ * User: khalid
+ * Date: 2/14/13
+ */
+public class Course {
+
+    private String courseName;
+    private String GPA;
+
+    Course(String GPA, String courseName ){
+        this.courseName  =   courseName;
+        this.GPA  =   GPA;
+
+    }
+
+    public String getCourse() {
+        return courseName;
+    }
+    public String getGPA() {
+        return GPA;
+    }
+
+
+    public String toString(){
+        StringBuilder sb = new StringBuilder();
+        sb.append(GPA+";");
+        sb.append(courseName);
+        return sb.toString();
+
+    }
+
+
+}