Wiki source code of Code Example: Data Structure Style vs. Object Style

Version 3.4 by chrisby on 2024/03/03 15:06

version	line-number	content
3.4	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
2.4	8	### Data Structure Style
2.1	9
2.4	10	type Square struct {
	11	length float
	12	}
	13
	14	type Circle struct {
3.2	15	radius float
2.4	16	}
	17
3.3	18	func Circumference(g Object) float {
3.2	19	switch type(g):
	20	case Square:
	21	return 4 * g.length
	22	case Circle:
	23	return 2 * PI * g.radius
2.4	24	}
2.1	25
3.4	26	1.
3.3	27
3.4	28	####
	29
2.3	30	#### Object-Oriented Style
2.2	31
3.3	32	interface GeometricObject {
	33	Circumference() float
	34	}
	35
	36	class Square implements GeometricObject {
2.3	37	length float
	38
	39	constructor(length float) {
	40	this.length = length
	41	}
	42
	43	func Circumference() float {
	44	return 4 * this.length
	45	}
	46	}
	47
3.3	48	class Circle implements GeometricObject {
2.3	49	radius float
	50
	51	constructor(radius float) {
	52	this.radius = radius
	53	}
	54
	55	func Circumference() float {
	56	return 2 * PI * this.radius
	57	}
	58	}