13-3_Factorial.java

package lesson13;

/*_à Íàéòè ôàêòîðèàë ÷èñëà.
Èñïîëüçîâàòü Generic, ââîä ÷èñåë ñ êîíñîëè, îáðàáîòêó try-catch
×èñëà äîëæíû áûòü îáúåêòàìè
*/

//_à ÄÎÐÀÁÎÒÀÒÜ: çàìåíèòü öèêë for - iterator

import java.util.Scanner;

public class Factorial <T> {

	private Scanner readNumber;
	private String inputNumber;
	private Integer number, factorial;
	
	public static void main(String[] args) {
				
		//_à Ýêçåìïëÿðû êëàññà Factorial 
		//_à Ñîçäàâàÿ ýêçåìïëÿðû, ìîæåì îòñëåæèâàòü çíà÷åíèÿ ïåðåìåííûõ â îòëàä÷èêå
		Factorial <String> stringFactorial = new Factorial();
		Factorial <Scanner> scannerFactorial = new Factorial();
		Factorial <Integer> integerFactorial = new Factorial();
		
		//_à Ïðèñâîèòü íà÷àëüíîå çíà÷åíèå äëÿ âîçìîæíîñòè ïðîõîäà ïî öèêëó - ðàñ÷åòà ôàêòîðèàëà
		integerFactorial.factorial = 1;
				
		scannerFactorial.readNumber = new Scanner(System.in);
		
		System.out.println("Ââåäèòå ÷èñëî : ");
		stringFactorial.inputNumber = scannerFactorial.readNumber.nextLine();
		
					
		//_à //_à Åñëè ââåäåííîå ñ êîíñîëè - ÷èñëî
		//_à ïåðåâîäèì åãî â òèï int
		try {
			integerFactorial.number = Integer.parseInt(stringFactorial.inputNumber);
			 
			//_à Âû÷èñëåíèå ôàêòîðèàëà
			for (int i=1; i<=integerFactorial.number; i++) {
				integerFactorial.factorial *= i;
							
			}
			
			System.out.println(integerFactorial.factorial.intValue());
				
		} catch (NumberFormatException e) {
			System.out.println("Âû ââåëè íå öåëîå ÷èñëî!");
		}
		
	}

}