Changes for page Code Example: Data Structure Style vs. Object Style

Summary

• Page properties (1 modified, 0 added, 0 removed)

Details

Page properties

Content

...	...	@@ -1,42 +8,32 @@
1		-### Use Cases
2		-
3		-This example is intended to demonstrate the extensibility differences between data structures and objects by extending them with
4		-
5		-1. an Area() function (extending behavior)
6		-1. a rectangle type (extending data type)
7		-
8	8	### Data Structure Style
9	9
10		- interface GeometricObject {}
11		-
12		- class Square implements GeometricObject {
	3	+ type Square struct {
13	13	length float
14	14	}
15	15
16		- class Circle implements GeometricObject {
	7	+ type Circle struct {
17	17	radius float
18	18	}
19	19
20		- function Circumference(g GeometricObject) float {
	11	+ func Area(g GeometricObject) float {
21	21	switch type(g):
22	22	case Square:
	14	+ return g.length * g.length
	15	+ case Circle:
	16	+ return PI * g.radius * g.radius
	17	+ }
	18	+
	19	+ func Circumference(g GeometricObject) float {
	20	+ switch type(g):
	21	+ case Square:
23	23	return 4 * g.length
24	24	case Circle:
25	25	return 2 * PI * g.radius
26	26	}
27	27
28		-1. Adding an Area() function with a very similar anatomy to Circumference() is easy because it only requires adding new code.
29		-1. Adding a new datatype, Rectangle, is harder because it requires touching existing code, namely any functions like Circumference() or Area() that need to be enabled handle this datatype.
30		-
31		-####
32		-
33	33	#### Object-Oriented Style
34	34
35		- interface GeometricObject {
36		- Circumference() float
37		- }
38		-
39		- class Square implements GeometricObject {
	29	+ class Square {
40	40	length float
41	41
42	42	constructor(length float) {
...	...	@@ -43,12 +43,16 @@
43	43	this.length = length
44	44	}
45	45
	36	+ func Area() float {
	37	+ return this.length * this.length
	38	+ }
	39	+
46	46	func Circumference() float {
47	47	return 4 * this.length
48	48	}
49	49	}
50	50
51		- class Circle implements GeometricObject {
	45	+ class Circle {
52	52	radius float
53	53
54	54	constructor(radius float) {
...	...	@@ -55,16 +55,11 @@
55	55	this.radius = radius
56	56	}
57	57
	52	+ func Area() float {
	53	+ return PI * this.radius * this.radius
	54	+ }
	55	+
58	58	func Circumference() float {
59	59	return 2 * PI * this.radius
60	60	}
61	61	}
62		-
63		-1. Adding a function Area() to GeometricObject Interface is hard since all classes implementing
64		-1. Adding a new datatype, Rectangle, is more difficult because it requires touching existing code, namely any functions like Circumference() or Area() that need to be enabled handle this datatype.
65		-
66		-### Conclusion
67		-
68		-asd
69		-
70		-