Pythagorean Theorem in Java

Question

I'm new to Java and am following a series of lectures on Stanford's YouTube. I know that the code works, but I'd like to know if it can be improved upon.

/*
 * File: PythagoreanTheorem.java
 * Name: Will
 * Section Leader: N/A, I'm freeloading the class off Youtube.
 * -----------------------------
 * This file is the starter file for the PythagoreanTheorem problem.
 */
import acm.program.*;
public class PythagoreanTheorem extends ConsoleProgram {
 public PythagoreanTheorem() {}
 public void run() {
 PythagoreanTheorem myCalculator = new PythagoreanTheorem();
 double a = readDouble("a= ");
 double b = readDouble("b= ");
 if(myCalculator.formula(a,b) == 
 Math.floor(myCalculator.formula(a,b))) {
 println("C= "+(int)myCalculator.formula(a,b));}
 else {
 println("C= "+myCalculator.formula(a,b));}
 }
 private double formula(double x, double y) {
 double c = Math.sqrt(x*x+y*y);
 return c;
 }
}

• Mast: For those wondering: get your ACM here
• Mast: "following a series of lectures on Stanford's Youtube" do you have a transcript of the problem statement to include? Did you write the code?
• Will K: I wrote the code. The problem asked to code a calculator to calculate the Pythagorean Theorem. The bit about returning an integer if it could was just me being annoyed at .0's.
• gervais.b: Except some weird formatting in your condition an a one line return in formula there is nothing much to say. But we do not have much to review.

Answer 1

I did not check the acm package but my 2 cents:

No need to instantate a PythagoreanTheorem each time

public void run() {
 PythagoreanTheorem myCalculator = new PythagoreanTheorem();

run is not static, so there already is an instance of PythagoreanTheorem availiable in the method, referencable by this.

So instead of:

if(myCalculator.formula(a,b) == 

You can use

if(this.formula(a,b) ==

Reuse results

You have a few calls to myCalculator.formula(a,b). While a and b do not change. You can store the result in a variable.

double c = myCalculator.formula(a,b)
if(c == Math.floor(c)) 
....