week3 lab

w3l.java

package comp601.assignment1;

import static java.lang.System.out;
import java.util.*;

public class Main {
	
	private static Scanner input = new Scanner(System.in);

	public static void main(String[] args) {
	
		out.printf("This is the assignment one demostration.\n\nStudent: Henry Jao.\n");
		while(true) {
			out.print("\nPlease enter the question number: ");
			String userInput = input.nextLine();
			
			// separation new line
			out.println();
			
			switch(userInput) {
				case "1":
					question1();
					break;
				case "2":
					question2();
					break;
				case "3":
					question3();
					break;
				case "4":
					question4();
					break;
				case "5":
					question5();
					break;
				case "e":
					out.println("Program terminated.");
					System.exit(0);
					break;
				default:
					out.println("Invalid input!");
						
			}
		}
		
	}
	
	// week 1 lab
	public static void question1() {
		//create two fixed length column
		String columnFmt = String.format("%%-%ds%%-%ds\n",30, 30);

		out.printf(columnFmt, "Escape sequence", "Description");
		out.printf(columnFmt, dash(20), dash(20));
		out.printf(columnFmt, "\\n", "New line character");
		out.printf(columnFmt, "\\t", "Horizontal tab character");
		out.printf(columnFmt, "\\\"", "Double quotes character");
	}
	
	private static String dash(int len) {
		if(len > 0) {
			return new String(new char[len]).replace('\0', '-');
		} else {
			return "";
		}
	}
	
	// questions
	
	// week 2 lab
	public static void question2() {
		
		out.print("Enter circle radius: ");
		
		Double radius = 0.0;
		
		try {
			// read radius value from user input
			radius = Double.parseDouble(input.nextLine());
		} catch (Exception ex) {
			out.println("invalid radius input");
			out.printf("Exception type: %s\n",ex.getClass());
			return;
		}
		
		Double diameter = radius * 2;
		Double perimeter = diameter * Math.PI;
		Double circleArea = Math.PI * radius * radius;
		

		String columns = String.format("%-12s%-12s%12s", "Radius", "Perimeter", "Area");
		String results = String.format("%-12s%-12.2f%12.2f", radius, perimeter, circleArea);
		
		out.println(columns);
		out.println(dash(columns.length()));
		out.println(results);
	}

	// week 3 lab
	public static void question3() {
		
		Double score = 0.0;
		
		while(true) {
			out.print("Enter a score: ");
			
			String userInput = input.nextLine().trim();
			Boolean validNumber = userInput.matches("\\d*(.)?\\d*");
			if(validNumber) {
				score = Double.parseDouble(userInput);
				String result = scoreRange(score);
				if( result == "") {
					out.println("Invalid score");
				} else {
					out.printf("The grade is %s.\n", result);
					break;
				}
				
			} else {
				out.println("Invalid score input");
			}
		}
	}
	
	private static String scoreRange(Double value) {
		if(value >=0 && value < 50) {
			return "D";
		}
		else if(value >= 50 && value < 70) {
			return "C";	
		}
		else if(value >= 70 && value < 80) {
			return "B";	
		}
		else if(value >= 80 && value <= 100) {
			return "A";	
		}
		else {
			return "";
		}
	}

	// week 3 lab
	public static void question4() {
		
		String nameOfCard = "";
		String inputLetter = "";
		
		while(nameOfCard == "") {
			out.print("Enter a card letter: ");
			
			inputLetter = input.nextLine().trim();
			
			switch(inputLetter.toLowerCase()) {
				case "j":
					nameOfCard = "Jack";
					break;
				case "q":
					nameOfCard = "Queen";
					break;
				case "k":
					nameOfCard = "King";
					break;
				case "a":
					nameOfCard = "Ace";
					break;
				default:
					out.printf("\"%s\" is not a valid card letter. Try again!\n", inputLetter);
					// keep looping
			}
		}
		out.printf("%s corresponds to %s.\n", inputLetter, nameOfCard);
	}
	
	public static void question5() {
		
		int numOfSensors = 0;
		while(true) {
			
			out.printf("Enter number of sensors: ");
			
			String userInput = input.nextLine().trim();
			if(userInput.matches("\\d*")) {
				numOfSensors = Integer.parseInt(userInput);
				break;
			}
		}
		
		double[] temeratureValues = new double[numOfSensors];
		
		int counter = 0;
		while(counter < numOfSensors) {
			out.printf("Enter tempture #%d: ", counter+1);
			String userInput = input.nextLine().trim();
			Boolean validNumber = userInput.matches("\\d*(.)?\\d*");
			if(validNumber) {
				temeratureValues[counter] = Double.parseDouble(userInput);
				counter++;
			}
		}
		
		Double sum = 0.0; // use for sum the temeratureValues
		Double max = -Double.MAX_VALUE; // use for max value of temeratureValues and initial with smallest value of double
		StringBuilder numBtw10to20 = new StringBuilder();
		
		
		for(int i = 0; i < temeratureValues.length; i++) {
			sum += temeratureValues[i];
			if(max < temeratureValues[i]) {
				max = temeratureValues[i];
			}
			if(temeratureValues[i] >= 10 && temeratureValues[i] <= 20) {
				numBtw10to20.append(String.format("%d, ", i + 1));
			}
		}
		
		Double avgOfTemperatureValues = sum / temeratureValues.length;
		out.printf("Average Temperature: %.2f\n", avgOfTemperatureValues);
		out.printf("Maximum Temperature: %.2f\n", max);
		// remove dangling chars
		String numBtw10to20Result = numBtw10to20.toString();
		if(numBtw10to20Result.length() >= 3) {
			numBtw10to20Result = numBtw10to20Result.substring(0, numBtw10to20Result.length()-2);
		}
		
		out.printf("Number of temperature between 10-20: %s",numBtw10to20Result);
		
	}
	
//	private static String dropDanglingString(String src, String dropChars) {
//		src.ma
//		return "";
//	}
}