打印正反星星 先正后反星星

1.

public class PrintStar {

	public static void main(String[] args) {
		
		printAttentionStar();
		printUpstandDownStar();
		printUpAndDownStar();

	}


/*
	*	
	**
	***
	****
	*****
*/
	private static void printAttentionStar() {
		for(int i=0; i<5; i++){
			for(int j=0; j<=i; j++){
				System.out.print("*");
			}
			System.out.println();
		}
		
	}
/*
	*****
	****
	***
	**
	*
*/	
	private static void printUpstandDownStar() {
		for (int i = 0; i < 5; i++) {
			for (int j = 5; j > i; j--) {
				System.out.print("*");
			}
			System.out.println();
		}
		
	}

	/*
	*
	**
	***
	****
	*****
	*****
	****
	***
	**
	*
*/	

	private static void printUpAndDownStar() {
		int index = 0;
		for (int i = 0; i < 10; i++) {
			if(index < 5){
				for (int j = 0; j <= i ; j++) {
					System.out.print("*");
				}
				System.out.println();
				index++;
			}
			if(index >=5){
				for (int k = 9; k > index  ; k--) {
					System.out.print("*");
				}
				System.out.println();
				index++;
			}
		}
			
	}	
		
	
}