Triangle

java.lang.Object
- eecs2030.lab3.Triangle

All Implemented Interfaces:

Comparable<Triangle>
```
public class Triangle
extends Object
implements Comparable<Triangle>
```
The Triangle class is immutable class that contains three variables to store the length of each side of the triangle, and methods to get its area and perimeter. The class implements Comparable interface to compare two triangles. It also overrides equals, hashCode, and toString from the Object class.

Author:

EECS2030 Summer 2019

Field Summary

Fields
Modifier and Type	Field and Description
`private double`	`a` The shortest side of the triangle
`private double`	`b` The side of medium length of the triangle
`private double`	`c` The longest side of the triangle
`private static int`	`numTriangles` Stores the number of objects instantiated from the `Triangle` class

Constructor Summary

Constructors
Constructor and Description

Triangle(double side1, double side2, double side3)
Initializes the new Triangle object using the provided sides in the arguments.

Constructors
Constructor and Description
`Triangle(double side1, double side2, double side3)` Initializes the new `Triangle` object using the provided sides in the arguments.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`compareTo(Triangle t)` Compares area of this triangle object and the other triangle `t`.
`boolean`	`equals(Object obj)` Compares this triangle with the argument `obj` of Object type.
`double`	`getA()` Accessor method that returns the smallest side of this triangle.
`double`	`getArea()` This method returns the area of the triangle.
`double`	`getB()` Accessor method that returns the medium side of this triangle.
`double`	`getC()` Accessor method that returns the longest side of this triangle.
`static int`	`getNumTriangles()` This method returns the number of objects instantiated from the `Triangle` class.
`double`	`getPerimeter()` This method returns the perimeter of the triangle.
`int`	`hashCode()` Generates a hashCode of this triangle using its sides length.
`boolean`	`isEquilateral()` Method to check if a triangle is equilateral triangle by having equal length sides.
`static boolean`	`isValid(double side1, double side2, double side3)` A `Triangle` is considered valid if and only if the sum of two sides be greater than the third side.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - numTriangles
```
private static int numTriangles
```
    Stores the number of objects instantiated from the Triangle class
  - a
```
private final double a
```
    The shortest side of the triangle
  - b
```
private final double b
```
    The side of medium length of the triangle
  - c
```
private final double c
```
    The longest side of the triangle
- Constructor Detail
  - Triangle
```
public Triangle(double side1,
                double side2,
                double side3)
```
    Initializes the new Triangle object using the provided sides in the arguments. The new triangle will have its shortest side stored in the variable a, the medium length side stored in the variable b, and the longest side stored in the variable c.
    Before initializing the triangle object, this constructor verifies that the provided sides are positive and valid as triangle sides otherwise it throws IllegalArgumentException. Verifying that the three sides can form a valid triangle is to be delegated to isValid(double, double, double) method.
    This constructor also increments the static variable numTriangles which tracks the number of Triangle objects created.
    
    Parameters:
    
    side1 - the first side of this triangle
    
    side2 - the second side of this triangle
    
    side3 - the third side of this triangle
    
    Throws:
    
    IllegalArgumentException - if the sides are not positive or the provided sides cannot form a valid triangle
- Method Detail
  - isValid
```
public static boolean isValid(double side1,
                              double side2,
                              double side3)
```
    A Triangle is considered valid if and only if the sum of two sides be greater than the third side. This condition has to be true for all three combinations of the sides.
    Example 1: valid triangle
    Assume you have a triangle that has the following sides side1 = 5, side2 = 10, and side3 = 7 then:
    5 + 10 greater than 7 (true), 5 + 7 greater than 10 (true), and 10 + 7 greater than 5 (true)
    
    Example 2: invalid triangle
    Assume you have a triangle that has the following sides side1 = 1, side2 = 2, and side3 = 7 then:
    1 + 2 greater than 7 (false). Then this is not a valid triangle
    
    Parameters:
    
    side1 - the first side of this triangle
    
    side2 - the second side of this triangle
    
    side3 - the third side of this triangle
    
    Returns:
    
    true if this is a valid triangle
  - isEquilateral
```
public boolean isEquilateral()
```
    Method to check if a triangle is equilateral triangle by having equal length sides.
    
    Returns:
    
    true if the triangle is equilateral otherwise false
  - getA
```
public double getA()
```
    Accessor method that returns the smallest side of this triangle.
    
    Returns:
    
    the side a of the triangle. This must be the smallest side.
  - getB
```
public double getB()
```
    Accessor method that returns the medium side of this triangle.
    
    Returns:
    
    the side b of the triangle. This must be the medium length side.
  - getC
```
public double getC()
```
    Accessor method that returns the longest side of this triangle.
    
    Returns:
    
    the side c of the triangle. This must be the longest side.
  - getPerimeter
```
public double getPerimeter()
```
    This method returns the perimeter of the triangle. The perimeter of a triangle is the sum of all its sides.
    
    Returns:
    
    the perimeter of the triangle
  - getArea
```
public double getArea()
```
    This method returns the area of the triangle. The area of a triangle given its sides a, b, and c is $$sqrt(s * (s - a) * (s - b) * (s - c))$$ where $s$ is half the perimeter (semiperimeter).
    
    Returns:
    
    the area of the triangle
  - getNumTriangles
```
public static int getNumTriangles()
```
    This method returns the number of objects instantiated from the Triangle class.
    
    Returns:
    
    the number of Triangle objects.
  - compareTo
```
public int compareTo(Triangle t)
```
    Compares area of this triangle object and the other triangle t.
    
    Specified by:
    
    compareTo in interface Comparable<Triangle>
    
    Parameters:
    
    t - the other triangle
    
    Returns:
    
    the value -1 if the area of this triangle is less than the argument's triangle area; +1 if the area of this triangle is greater than the argument's; and 0 if this area of this triangle is equal to the argument's within the specified tolerance ShapeUtil.TOL.
    
    Throws:
    
    IllegalArgumentException - if the argument is null
  - hashCode
```
public int hashCode()
```
    Generates a hashCode of this triangle using its sides length. Use Eclipse to generate this method for you.
    
    Overrides:
    
    hashCode in class Object
    
    Returns:
    
    some hashCode
  - equals
```
public boolean equals(Object obj)
```
    Compares this triangle with the argument obj of Object type. This method overrides the base method defined in the root class Object.
    Two triangles are equal if the difference between the sides of the first triangle and the sides of second triangle is within the allowed tolerance specified in ShapeUtil.TOL
    
    Overrides:
    
    equals in class Object
    
    Returns:
    
    true if the triangle is equal to the argument triangle within the tolerance specified in ShapeUtil.TOL.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class Triangle

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

numTriangles

a

b

c

Constructor Detail

Triangle

Method Detail

isValid

isEquilateral

getA

getB

getC

getPerimeter

getArea

getNumTriangles

compareTo

hashCode

equals

toString