finished code

.classpath

+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.junit.JUNIT_CONTAINER/5"/>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

.gitignore

+/bin/

.project

+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>sem2Formative</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

.settings/org.eclipse.jdt.core.prefs

+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.8

src/Complex.java

+
+public class Complex 
+{
+	double real;
+	double imag;
+
+	double magnitude;	
+	double argument;
+	
+	public Complex()
+	{
+		real = 0;
+		imag = 0;
+	}
+	
+	public Complex(double _real, double _imag) 
+	{
+		real = _real;
+		imag = _imag;
+	}
+	
+	public double imag()
+	{
+		return imag;
+	}
+	
+	public double real()
+	{
+		return real;
+	}
+	
+	public double magnitude()
+	{
+
+		double answer1 = Math.pow(real, 2);
+		double answer2 = Math.pow(imag, 2);
+		
+		magnitude = Math.sqrt(answer1 + answer2);
+		
+		return magnitude;
+	}
+
+	public double argument()
+	{		
+		argument = Math.atan2(imag, real);
+	
+		return argument;
+	}
+
+	public Complex add(Complex complex)
+	{
+		double answer1 = this.real + complex.real;
+		double answer2 = this.imag + complex.imag;
+		
+		complex.real = answer1;
+		complex.imag = answer2;
+				
+		return complex;
+	}
+	
+	public String toString()
+	{
+		if (real == 0.0)
+		{
+			String imagString = Double.toString(imag);
+			return "j" + imagString;
+		}
+		if (imag == 0.0)
+		{
+			String realString = Double.toString(real);
+			return realString;
+		}
+		if (imag < 0.0)
+		{
+			String realString = Double.toString(real);
+			
+			double num1 = Math.abs(imag);
+			String imagString = Double.toString(num1);
+			
+			return realString + " - j" + imagString;
+		}
+		else
+		{
+			String realString = Double.toString(real);
+			String imagString = Double.toString(imag);
+			
+			return realString + " + j" + imagString;
+		}
+	}
+
+}

src/ComplexTest.java

+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class ComplexTest {
+
+    @Test
+    void testBasic() {
+        /* Constructor should put the first parameter as the real part and second as the imaginary part.
+         * real() should return real part, imag() imaginary part.
+         */
+        Complex a = new Complex(4.2, 5.7);
+        assertEquals(4.2, a.real(), 1e-6);
+        assertEquals(5.7, a.imag(), 1e-6);
+        Complex b = new Complex();
+        assertEquals(0, b.real(), 1e-6);
+        assertEquals(0, b.imag(), 1e-6);
+    }
+    
+    @Test
+    void testMagnitude() {
+        /* magnitude() should return the magnitude of the complex number */
+        Complex a = new Complex(9.6, 11.5);
+        assertEquals(14.98032042, a.magnitude(), 1e-6);
+    }
+    
+    @Test
+    void testArgument() {
+        /* argument() should return the argument of the complex number */
+        Complex a = new Complex(9.6, 11.5);
+        assertEquals(0.87520335, a.argument(), 1e-6);
+    }
+    
+    @Test
+    void testAdd() {
+        /* add() should return a new complex number which is the sum of this and the parameter */
+        Complex a = new Complex(6.6, 12.9);
+        Complex b = new Complex(13.1, 13.5);
+        Complex c = a.add(b);
+        assertEquals(19.7, c.real(), 1e-6);
+        assertEquals(26.4, c.imag(), 1e-6);
+    }
+    
+    @Test
+    void testToString() {
+        /* toString() should return a string like 1.2 + j3.4 where 1.2 is the real part
+         * and 3.4 the imaginary part.
+         */
+        Complex a = new Complex(1.2, 3.4);
+        assertEquals("1.2 + j3.4", a.toString());
+        Complex b = new Complex(1.2, 0.0);
+        assertEquals("1.2", b.toString());
+        Complex c = new Complex(0.0, 9.3);
+        assertEquals("j9.3", c.toString());
+        Complex d = new Complex(1.2, -3.4);
+        assertEquals("1.2 - j3.4", d.toString());
+    }
+}