for语句的简单应用①

InputStreamReader isr = new InputStreamReader(System.in);
		BufferedReader br = new BufferedReader(isr);
		System.out.println("请输入一个数:");
		int lay = 0;
		try {
			String input = br.readLine();

			lay = Integer.parseInt(input);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		// int lay=4;
		/*
		 * for(int i=1;i<=lay;i++) { for(int j=1;j<=i;j++) {
		 * System.out.print("*"); } System.out.println();//换行 }
		 */

		for (int i = 1; i <= lay; i++) {
			for (int j = 1; j <= lay - i; j++) {
				System.out.print(" ");
			}

			for (int k = 1; k <= (i - 1) * 2 + 1; k++) {
				System.out.print("*");
			}
			System.out.println();
		}