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

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...	...	@@ -7,17 +7,15 @@
7	7
8	8	### Data Structure Style
9	9
10		- interface GeometricObject {}
11		-
12		- class Square implements GeometricObject {
	10	+ type Square struct {
13	13	length float
14	14	}
15	15
16		- class Circle implements GeometricObject {
	14	+ type Circle struct {
17	17	radius float
18	18	}
19	19
20		- function Circumference(g GeometricObject) float {
	18	+ func Circumference(g Object) float {
21	21	switch type(g):
22	22	case Square:
23	23	return 4 * g.length
...	...	@@ -25,8 +25,7 @@
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.
	26	+1.
30	30
31	31	####
32	32
...	...	@@ -59,11 +59,3 @@
59	59	return 2 * PI * this.radius
60	60	}
61	61	}
62		-
63		-1. Adding a function Area() to the GeometricObject interface is hard because it requires touching existing code, namely extending all Square and Circle classes with the new function.
64		-1. Adding a new datatype, Rectangle, is easy because only new code is added, namely a Rectangle class.
65		-
66		-### Conclusion
67		-
68		-* The lesson learned here is that data structures are easy to extend with functions, and objects are easy to extend with data types.
69		-* Although the difference between the two styles may seem insignificant in this simplified example, it has serious implications in complex production codebases with multiple data types and behaviors.