Project 4

Code

    /// Name: Xinting Chen
    /// Period: 7
    /// Program Name: Project 4
    /// File Name: draft.java
    /// Date Finished: 5/9/2016
  
        import java.util.Scanner;
      
        public class draft
        {
        	public static void main( String[] args )
        	{
        		Scanner keyboard = new Scanner(System.in);
        
        		String a = "";
        		double c = 0;
                
        		System.out.println(" Calculator ");
        
        		do
        		{
        					System.out.print("> ");
        					a = keyboard.next();
        
        					if (Numeric.isNumeric(a)) 
                            {
        						double d = Double.parseDouble(a);
        						c = basic(d, keyboard);
        					} else c = trig(a, keyboard);
        
        					c = threeDecimals(c);
                       if (!a.equals("0")) System.out.println(c);
        			
        				{
        					System.out.println("Wrong input, retry.");
        				}
        
        		} while (!a.equals("0"));
        
        		System.out.println(" Bye ");
        	}
        
        	public static double threeDecimals(double c)
        	{
        		c *= 1000;
        		c = Math.round(c);
        		c /= 1000;
        		return c;
        	}
        
        	public static double basic(double a,Scanner keyboard)
        	{
        
        		String choice = keyboard.next();
        		double b = keyboard.nextDouble();
        
        		switch (choice) {
        			case "+":
        				return (a + b);
        			case "-":
        				return (a - b);
        			case "*":
        				return (a * b);
        			case "/":
        				return (a / b);
        			case "^":
        				return (Math.pow(a,b));
        			default: {
        				System.out.println("Undefined operator: '" + choice + "'.");
        				return 0;
        			}
        		}
        	}
        
        	public static double trig(String a,Scanner keyboard)
        	{
        		double b = keyboard.nextDouble();
        
        		b*= Math.PI/180;
        
        		switch (a)
        		{
        			case "sin":
        				return (Math.sin(b));
        			case "cos":
        				return (Math.cos(b));
        			case "tan":
        				return (Math.tan(b));
        			case "cot":
        				return (Math.pow(Math.tan(b),-1));
        			case "sec":
        				return (Math.pow(Math.cos(b),-1));
        			case "csc":
        				return (Math.pow(Math.sin(b),-1));
        			default:
        			{
        				System.out.println("Undefined operator: '" + a + "'.");
        				return 0;
        			}
        		}
        	}
        }


    

Picture of the output