Compiles, but doesn't run - also objects used like arrays?

Question

Hello. I am a way newbie at Java, but I like it a lot. I'm using it to write a little final project for an intro CS class I'm taking. The program is a little mileage calcuator. Okay, so here's what I don't get. I started to write out the program and everything was compiling, my output and input were working. Then I started to add some classes and objects. Now it still compiles, but the command line just gives me "hit any key". None of my output or input stuff. What happened?
While I'm at it, in C++ I would've used a little array to store a bit of data for this app. Can I use multile objects of a class and iterate through them in a for each in the same way?
Any help much appreciated.
Here's the code:
//Joanna Grossman
//mileage calculator
//final project SWE 150
//creates vehicle class
class vehicle {
     int id;
     String name;
     int mpg;
//creates different vehicle objects - may need to be changed to array
class vehicleTypes {
     public static void main(String args[]) {
          vehicle SUV = new vehicle();
          vehicle hybrid = new vehicle();
          vehicle FordTaurus = new vehicle();
          //assigns values for cars
          SUV.id = 1;
          SUV.name = "SUV";
          SUV.mpg = 10;
          hybrid.id = 2;
          hybrid.name = "Honda Civic";
          hybrid.mpg = 50;
          FordTaurus.id = 3;
          FordTaurus.name = "Ford Taurus";
          FordTaurus.mpg = 23;
//creates location class
class location {
     int id;
     String name;
     int miles2Loc1;
     int miles2Loc2;
     int miles2Loc3;
//creates location objects
class locationObjects {
     public static void main(String args[]) {
          location Burlington = new location();
          location NewYork = new location();
          location Syracuse = new location();
          //assigns values to locations
          Burlington.id = 1;
          NewYork.id=2;
          Syracuse.id = 3;
          Burlington.name = "Burlington";
          Burlington.miles2Loc1 = 0;
          Burlington.miles2Loc2 = 308;
          Burlington.miles2Loc3 = 270;
          NewYork.name = "New York";
          NewYork.miles2Loc1 = 308;
          NewYork.miles2Loc2 = 0;
          NewYork.miles2Loc3 = 246;
          Syracuse.name = "Syracuse";
          Syracuse.miles2Loc1 = 270;
          Syracuse.miles2Loc2 = 246;
          Syracuse.miles2Loc3 = 0;
//mainline logic
class mileageCalculator {
     public static void main(String args[])
          throws java.io.IOException {
          char play;
          play='y';
               System.out.println("Would you like to calculate your mileage?");
               System.out.println("Please press \"y\" for \'yes\' or \"n\" for \'no\'\nThen Press \"Enter\"");
               play = (char) System.in.read();
               System.out.println("Your answer is "+play);
               System.out.println("What is your destination?");
               System.out.println("Press press it's number:");
               System.out.println("1\tBurlington\n2\tNew York\n3\tSyracuse");
}

Answer 1

You're probably "running" one of the classes that doesn't produce any output. The main() method is intended to be an application's entry point, not someplace you just cram all your code. You'll want to learn about methods and how objects communicate with each other. Have a look at the following:
The Java� Tutorial - Trail: Learning the Java Language
Good luck!
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