Introduction

Hello all!
After browsing the web for a bit, I decided on this place to help me with my future endeavors with Java. Currently, I'm a metal worker, but back in high school I took C++ and Java classes. I just started school and am seeking a Software Development degree. Still doing my basics, no programming classes yet.

Also, I have a coding related question:

I started working out, and I was wanting to make a little program that would calculate the amount of carbs and protein I need per meal, based off # of meals I can eat in a day. It has been a while since high school, but I seem to remember a bit from C++, but cannot remember proper Java syntax or remember flow characteristics.

Here is the code that I have so far:

Code:

---

/**
 *
 * @author nathan sizemore
 */
public class Main
{

    //The basic array that all methods need to pass around
    static int[] protein_and_carb = new int[2];

    //Assigns proper values to protein_and_carb[]
    public void basic_calculation()
    {
        int loop_counter = 0;
        double multiplier = 1.5;

        while (loop_counter < protein_and_carb.length)
        {
            protein_and_carb[loop_counter] = protein_and_carb[loop_counter] * multiplier;
            multiplier += 0.5;
            loop_counter++;
        }
    }


    public static void main(String[] args)
    {
        int weight, means_per_day;


        System.out.println("Weight: ");
        main.weight = System.in.read();
       
        System.out.println("Meals per day: ");
        main.meals_per_day = System.in.read();
       
        protein_and_carb[0] = weight;
       
        basic_calculation(protein_and_carb);
       
        System.out.println("You need: ", protein_and_carb[0], "g of protein daily.");
        System.out.println("You need: ", protein_and_carb[0] \ meals_per_day, "g of protein per meal");
        System.out.println("You need: ", protein_and_carb[1], "g of carbohydrates daily.");
        System.out.println("You need: ", protein_and_carb [1] \ meals_per_day, "g of carbohydrates per meal");
    }

}

---

The build errors are all from the main(strings[]) section. I have searched, but cannot seem to figure out what I am doing wrong, or the proper syntax for what I am trying.
Any help is greatly apprecited!

Cheers,
Nathan

Hello

What errors, which lines?

Code:

---

        System.out.println("You need: ", protein_and_carb[0], "g of protein daily.");
        System.out.println("You need: ", protein_and_carb[0] \ meals_per_day, "g of protein per meal");
        System.out.println("You need: ", protein_and_carb[1], "g of carbohydrates daily.");
        System.out.println("You need: ", protein_and_carb [1] \ meals_per_day, "g of carbohydrates per meal");

---

Errors:

Code:

---

Created dir: /home/nathan/NetBeansProjects/myPT/build/empty
Compiling 1 source file to /home/nathan/NetBeansProjects/myPT/build/classes
/home/nathan/NetBeansProjects/myPT/src/mypt/Main.java:49: illegal character: \92
        System.out.println("You need: ", protein_and_carb[0] \ meals_per_day, "g of protein per meal");
/home/nathan/NetBeansProjects/myPT/src/mypt/Main.java:49: not a statement
        System.out.println("You need: ", protein_and_carb[0] \ meals_per_day, "g of protein per meal");
/home/nathan/NetBeansProjects/myPT/src/mypt/Main.java:49: ';' expected
        System.out.println("You need: ", protein_and_carb[0] \ meals_per_day, "g of protein per meal");
/home/nathan/NetBeansProjects/myPT/src/mypt/Main.java:51: illegal character: \92
        System.out.println("You need: ", protein_and_carb [1] \ meals_per_day, "g of carbohydrates per meal");
/home/nathan/NetBeansProjects/myPT/src/mypt/Main.java:51: not a statement
        System.out.println("You need: ", protein_and_carb [1] \ meals_per_day, "g of carbohydrates per meal");
/home/nathan/NetBeansProjects/myPT/src/mypt/Main.java:51: ';' expected
        System.out.println("You need: ", protein_and_carb [1] \ meals_per_day, "g of carbohydrates per meal");
6 errors
/home/nathan/NetBeansProjects/myPT/nbproject/build-impl.xml:528: The following error occurred while executing this line:
/home/nathan/NetBeansProjects/myPT/nbproject/build-impl.xml:261: Compile failed; see the compiler error output for details.
BUILD FAILED (total time: 1 second)

---

When pressing alt+ender in Netbeans, they give me this, but have no idea of what they are talking about?

Code:

---

cannot find symbol
  symbol:  method println(java.lang.String,int,java.lang.String)
  location: class java.io.PrintStream

---

Ah,

Two ways to do this. One is to concatenate your Strings with the + operation, e.g.,

Code:

---

System.out.println("You need: " + protein_and_carb[0] / meals_per_day + "g of protein per meal");

---

Also, Java also has a printf, and while I'm not 100% sure, I think that it's somewhat close to C++'s version of this. To learn more about how it works, check out the Formatter API.

Code:

---

System.out.printf("You need: %.2f g of protein per meal%n", protein_and_carb[0] / meals_per_day);

---

The problem is that you used \, which is the escape character, not division, try switching to / instead and see what happens.

Quote:

---

Originally Posted by nathansizemore

Code:

---

    //Assigns proper values to protein_and_carb[]
    public void basic_calculation() { ... }
        ...
        basic_calculation(protein_and_carb);

---

---

I'm surprised that the compiler didn't catch this error, i.e. the method basic_calculation() doesn't take any parameter(s). I think there are a few semantic errors there as well (something no compiler can catch).

kind regards,

Jos

Thanks for the help guys. Although I haven't figured out the exact problem, I have cleaned up the code a bit and think I have it somewhat close to running, but still not there. I decided to read a get a book and start from scratch. After searching around here, I decided to go with Head First Java. Like it so far. I have Netbeans, but cannot get even simple "Hello World" type programs to open up to see if they build? So I decided to switch to Notepad and execute from Terminal and use javac. The same result. They compile, but nothing comes on the screen? Any help would be appreciated. I am using Ubuntu 11.04. This is the source code:

Code:

---

import java.awt.*;
import java.awt.event.*;

public class Party
{
        public static void main (String[] args)
        {
                System.out.print("Hello World!");
        }
}

---

This is what I am doing at the Terminal:

Code:

---

nathan@ubuntu:~/Documents$ sudo javac Party.java

---

But I get no result. Simply another line to nathan@ubuntu:~/Documents$
Do I need some type of statement that keeps the window open until I press a key maybe? I tried using System.in.read() afterwards, but it throws up an error:

Code:

---

nathan@ubuntu:~/Documents$ sudo javac Party.java
Party.java:9: unreported exception java.io.IOException; must be caught or declared to be thrown
                System.in.read();

---

Thanks for any help!

I'm not very familiar with linux, but is the sudo necessary? What happens if you just type

Code:

---

javac Party.java

---

Also, Head First Java is an excellent beginner book. Instead of making a very long post with all my other suggestions on books, I will link you to a blog post where I give some suggested books: My book suggestions

The code you have for the hello world is fine, you should be able to compile it fine.

Did your file compile? Do an 'ls' and see if there's a file named Party.class. If it's there run it.

kind regards,

Jos

Yeah, it made a Party.class file and that is what I needed to open. Thanks again!