/*
 * The above slash-star starts a multi-line comment.
 * 
 * Basics in Java: special symbols, data types,
 * operators, expressions, input/output, and Strings.
 * 
 * CSCI 51, Stough
 * January 27, 2009
 * 
 * The below star-slash ends the multi-line comment.
 */

import java.util.Scanner; //The Scanner data type is used to get input
						//from the user.

public class BasicsJava {
	// *data types*: the basic kinds of data (number, character, etc.) that
	// a *variable* stores

	public static void main(String[] args) {
		// *variable*: a named location storing some value. see naming rules.
		int i = 1; // i is an integer/whole number, and is assigned the val 1.
		double d; // d is a double-precision floating point number - e.g. 12.2
		char c; // c is a typing character, such as '+' or the letter 'a'.

		// *special symbols*: +, -, /, *, &, !, cannot be used in variable name

		// *expression*: collection of variables, literals, and operators, that
		// can be evaluated to some data type.
		i = 12 * 7 + 5; //i is set to be the result of evaluating the expr,
						//namely, i is set to 89.
		System.out.println("i is " + i); //output. the *parameter* sent is an
										//*expression* evaluating to a String
		
		d = (1.2347*i) - 10.7; //an expr involving floating point and integer
							//operands will be evaluated to a floating point.
		System.out.println("d is " + d);  //output.
		System.out.printf("\tformatted to two decimal places, d is %.2f\n",d);
		//The above formats the output. See printf in the API. 
		//'\t' forces an indentation, '\n' forces a carriage return, %.2f
		//says that I want a float with two places after the decimal. %f
		//by itself would say to output as is (with more decimal places).
		
		String s = "my new String has not too many words in it.";
		//s is a String containing the literal sequence of characters above.
		System.out.print(s + "  And here are a few more.\n");
		//print (without the ln) prints without the carriage return, so I 
		//added it.
		
		
		Scanner scan = new Scanner(System.in); 
		//just like int i, Scanner scan declares a new Scanner object/variable,
		//then the new Scanner actually constructs this object. int, double,
		//and other *non-capped data types* do not require the new operator 
		//because they are *primitive*.
		
		System.out.print("Please give me the height and width of " 
				+ "a rectangle: ");
		double h = scan.nextDouble();
		double w = scan.nextDouble();  //h and w contain the numbers entered 
										//by the user.
		
		//Compute the area.
		double area = h * w; //pretty easy, area is a double set to be h*w.
		
		System.out.print("The area of a rectangle with height " + h 
				+ " and width " + w + " is " + area + ". Bye\n");
		
	} //This brace ends the main method.
} //This brace ends the BasicsJava class definition.