symbol not found error

rmartyce · #1 (**permalink**) 05-22-2008, 09:35 PM

I have a program (see below). Can someone tell me why I'm getting the error...

C:\CourseUnits.java:95: cannot find symbol
symbol : variable CourseUnitArray
location: class CourseUnits
CourseUnitArray[0] = new CourseUnits("name","num");
^
C:\CourseUnits.java:95: cannot find symbol
symbol : constructor CourseUnits(java.lang.String,java.lang.String)
location: class CourseUnits
CourseUnitArray[0] = new CourseUnits("name","num");
^
2 errors

Tool completed with exit code 1

The CourseUnits constructor is there. The classpath is .;PATH;C:\;
I've been stumped for 2 days, so any assistance is greatly appreciated.

import java.lang.*;
import java.util.*;
import java.io.*;
import java.util.Scanner;

public class CourseUnits {
private Integer courseUnitID;
private String courseUnitName;
private String courseUnitNum;
private static int lastAssignedID = 10000;
//in the real world the ArrayList would not be used. Instead a datbase table would
//be used.
private static ArrayList<CourseUnits> courseUnitArray = new ArrayList<CourseUnits>();

//default constructor - no parameters
public void CourseUnits(){
}

public void CourseUnits(String cName, String cNum){
courseUnitName = cName;
courseUnitNum = cNum;
courseUnitID = createCourseUnitID();
courseUnitArray.add(this);
}

private static int createCourseUnitID() {
++lastAssignedID;
return lastAssignedID;
}

public String courseUnitName () {
return this.courseUnitName;
}

public String courseUnitNum () {
return this.courseUnitNum;
}

public int courseUnitID () {
return this.courseUnitID;
}

public static void listCourseUnit(int idx){
CourseUnits holdCourseUnit = new CourseUnits();
holdCourseUnit = courseUnitArray.get(idx);
System.out.println(holdCourseUnit.courseUnitID + " " + holdCourseUnit.courseUnitName + " " + holdCourseUnit.courseUnitNum);
}

public static void listCourseUnitArray(){
CourseUnits holdCourseUnit = new CourseUnits();
for (int i=0; i < courseUnitArray.size(); i++){
holdCourseUnit = courseUnitArray.get(i);
System.out.println(holdCourseUnit.courseUnitID + " " + holdCourseUnit.courseUnitName + " " + holdCourseUnit.courseUnitNum);
}
}

public static int findCourseUnit(int inCourseUnitID){
CourseUnits holdCourseUnit = new CourseUnits();
for (int i=0; i < courseUnitArray.size(); i++){
holdCourseUnit = courseUnitArray.get(i);
if (inCourseUnitID == holdCourseUnit.courseUnitID())
return i;
}
return -1;
}

public static void deleteCourseUnit(int idx){
courseUnitArray.remove(idx);
}

private static BufferedReader stdin =
new BufferedReader( new InputStreamReader( System.in ) );

Scanner input = new Scanner( System.in );

public static void main(String[] args) throws IOException {

if (courseUnitArray.size() == 0)
System.out.println("There are no courses");
else
listCourseUnitArray();

String [] courseUnitNames = {"English 101", "Algebra 101","Biology 101","Geometry 101","Englis Literature"};
String [] courseUnitNums = {"E101","M101","Sci101","M102","E103"};

CourseUnits courseUnitArray[] = new CourseUnits[5];
CourseUnitArray[0] = new CourseUnits("name","num");

}
}

thanks.

Eranga · #2 (**permalink**) 05-23-2008, 07:58 AM

Defining the constructor is wrong. There is no return type in constructor. Even no void there.

You have use the same name for ArrayList as well as object array. You should rename one of them.

Code:

import java.util.*;
import java.io.*;
import java.util.Scanner;

public class CourseUnits {
    private Integer courseUnitID;
    private String courseUnitName;
    private String courseUnitNum;
    private static int lastAssignedID = 10000;
        //in the real world the ArrayList would not be used. Instead a datbase table would
        //be used.
    private static ArrayList<CourseUnits> courseUnitArray = new ArrayList<CourseUnits>();

    //default constructor - no parameters
    public CourseUnits() {
    }

    public CourseUnits(String cName, String cNum){
        courseUnitName = cName;
        courseUnitNum = cNum;
        courseUnitID = createCourseUnitID();
        courseUnitArray.add(this);
    }

    private static int createCourseUnitID() {
        ++lastAssignedID;
        return lastAssignedID;
    }

    public String courseUnitName () {
        return this.courseUnitName;
    }

    public String courseUnitNum () {
        return this.courseUnitNum;
    }

    public int courseUnitID () {
        return this.courseUnitID;
    }

    public static void listCourseUnit(int idx){
        CourseUnits holdCourseUnit = new CourseUnits();
        holdCourseUnit = courseUnitArray.get(idx);
        System.out.println(holdCourseUnit.courseUnitID + " " + holdCourseUnit.courseUnitName + " " + holdCourseUnit.courseUnitNum);
    }

    public static void listCourseUnitArray(){
        CourseUnits holdCourseUnit = new CourseUnits();
        for (int i=0; i < courseUnitArray.size(); i++){
            holdCourseUnit = courseUnitArray.get(i);
            System.out.println(holdCourseUnit.courseUnitID + " " + holdCourseUnit.courseUnitName + " " + holdCourseUnit.courseUnitNum);
        }
    }

    public static int findCourseUnit(int inCourseUnitID){
        CourseUnits holdCourseUnit = new CourseUnits();
        for (int i=0; i < courseUnitArray.size(); i++){
            holdCourseUnit = courseUnitArray.get(i);
            if (inCourseUnitID == holdCourseUnit.courseUnitID())
                return i;
        }
        return -1;
    }

    public static void deleteCourseUnit(int idx){
        courseUnitArray.remove(idx);
    }

    private static BufferedReader stdin =
        new BufferedReader( new InputStreamReader( System.in ) );

    Scanner input = new Scanner( System.in );
    @SuppressWarnings("empty-statement")
    public static void main(String[] args) throws IOException {
        if (courseUnitArray.size() == 0)
            System.out.println("There are no courses");
        else
            listCourseUnitArray();
        
        String [] courseUnitNames = {"English 101", "Algebra 101","Biology 101","Geometry 101","Englis Literature"};
        String [] courseUnitNums = {"E101","M101","Sci101","M102","E103"};

        CourseUnits courseUnitArray2[] = new CourseUnits[5];
        courseUnitArray2[0] = new CourseUnits("name", "num");;

    }
}