I’m not sure if it’s because I haven’t slept or because I’ve never encountered it before, but I have no idea what this error means. I’m trying to compile a program that interacts with a doubly linked list using a custom object, and the compiler keeps telling me the following:
19 errors found:
File: Z:\CS121\Project 6\prog6.java [line: 127]
Error: Z:\CS121\Project 6\prog6.java:127: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 130]
Error: Z:\CS121\Project 6\prog6.java:130: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 134]
Error: Z:\CS121\Project 6\prog6.java:134: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 136]
Error: Z:\CS121\Project 6\prog6.java:136: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 138]
Error: Z:\CS121\Project 6\prog6.java:138: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 140]
Error: Z:\CS121\Project 6\prog6.java:140: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 143]
Error: Z:\CS121\Project 6\prog6.java:143: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 144]
Error: Z:\CS121\Project 6\prog6.java:144: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 145]
Error: Z:\CS121\Project 6\prog6.java:145: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 146]
Error: Z:\CS121\Project 6\prog6.java:146: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 149]
Error: Z:\CS121\Project 6\prog6.java:149: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 151]
Error: Z:\CS121\Project 6\prog6.java:151: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 156]
Error: Z:\CS121\Project 6\prog6.java:156: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 158]
Error: Z:\CS121\Project 6\prog6.java:158: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 160]
Error: Z:\CS121\Project 6\prog6.java:160: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 161]
Error: Z:\CS121\Project 6\prog6.java:161: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 165]
Error: Z:\CS121\Project 6\prog6.java:165: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 166]
Error: Z:\CS121\Project 6\prog6.java:166: class, interface, or enum expected
File: Z:\CS121\Project 6\prog6.java [line: 169]
Error: Z:\CS121\Project 6\prog6.java:169: class, interface, or enum expected
This is my code:
import java.util.LinkedList;
import java.util.ListIterator;
import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
class prog6 {
public static void main(String args[]) throws FileNotFoundException
{
Scanner kb=new Scanner(System.in);
String tempName, keyName;
Product tempProduct, temp;
double tempPrice;
boolean found;
/* Here, add code to delcare and/or create a linked list
and, if necessary, an iterator.
*/
LinkedList<Product> list = new LinkedList<Product>();
ListIterator<Product> iter = list.listIterator();
//the following code reads product data from the file data.txt
//and saves the product data in the linked list
Scanner infile=new Scanner(new File("data.txt"));
while(infile.hasNextLine())
{
tempProduct=tempProduct.addFirst(infile.nextLine(), infile.nextDouble());
infile.nextLine(); //skip end-of-line
/*here, add code to add the object tempProduct
to the beginning of the linked list*/
}
infile.close();
while(true)
{
System.out.println();
System.out.println();
//show prompt messages and menu
System.out.println("Please select one of the follwing actions:");
System.out.println("q - Quit");
System.out.println("a - print the product list");
System.out.println("b - add a product");
System.out.println("c - enter a product name to find the product record");
System.out.println("d - delete a product");
System.out.println("Please enter q, a, b, c, or d:");
String selection=kb.nextLine(); //read user's selection
if (selection.equals("")) continue; //if selection is "", show menu again
switch (selection.charAt(0))
{
case 'q':
System.out.println("Thank you");
return;
/*write code for the cases 'a','b','c' and 'd' */
case 'a':
temp = list;
while (temp != null)
{
System.out.println (temp.data);
temp = temp.next;
}
System.out.println();
break;
case 'b':
System.out.println("Please enter the name of the new product:");
tempName = kb.nextLine();
System.out.println("Please enter the price of the new product:");
tempPrice = kb.nextDouble();
temp = new node(tempName, tempPrice);
temp.next = list;
list = temp;
break;
case 'c':
System.out.println("Please enter a product name:");
n=kb.nextLine();
tempProduct = list.search(n);
if(tempProduct == null)
System.out.println("Cannot find product named " + n);
else
System.out.println("Product found: " + tempProduct);
break;
case 'd':
System.out.println("Please enter name of a customer to remove from list:");
tempString = kb.nextLine();
list = delete(list, tempString);
break;
default: System.out.println("Incorrect selection.\n");
} //end switch
} //end while
} //end main();
} //end class prog6
class Product
{
String name;
double price;
public Product(String n, double p)
{ name=n;
price=p;
} //end Constructor
public String toString()
{
return String.format("%-20s%10.2f", name, price);
}
} //end class Product
public Product search (String key)
{
node temp = head;
while (temp != null)
{
if (temp.data.name.equals(key))
return temp.data;
else
temp = temp.next;
}
return null;
}
public void add (Product a)
{
node temp = new node (a);
temp.next = head;
head = temp;
}
public Boolean delete (String namekey, Product a)
{
node previous = null;
node current = head;
while (current != null)
{
if (current.name.equals(namekey))
{
current = current.next;
if (previous == null)
previous = current;
else
previous.next = current;
return true;
}//end if
else
{
previous = current;
current = current.next;
}//end else
}//end while
return false;
}
Any help is greatly appreciated!
The error is at line
and the cause is that java accepts only class, interface or enum definitions at the top level (as the message quite clearly states).