Java 打印左箭头星形图案程序

编写一个 Java 程序，使用 for 循环打印左箭头星形图案。在此左箭头示例中，第一个嵌套的 for 循环打印左箭头的上半部分，而其他代码打印左箭头的下半部分。

package ShapePrograms;

import java.util.Scanner;

public class LeftArrow1 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		int i, j;
		
		System.out.print("Enter Left Arrow Pattern Rows = ");
		int rows = sc.nextInt();
		
		System.out.println("Printing Left Arrow Star Pattern");
		
		for (i = 1 ; i <= rows; i++ ) 
		{
			for (j = 1 ; j <= rows - i; j++ ) 
			{
				System.out.print(" ");	
			}
			for (j = i ; j <= rows; j++ ) 
			{
				System.out.print("*");
			}
			System.out.println();
		}
		
		for (i = 1 ; i < rows; i++ ) 
		{
			for (j = 0 ; j < i; j++ ) 
			{
				System.out.print(" ");
			}
			for (j = 0 ; j <= i; j++ ) 
			{
				System.out.print("*");
			}
			System.out.println();
		}
	}
}

在此左箭头星形图案程序中，我们用while 循环替换了 for 循环。

package ShapePrograms;

import java.util.Scanner;

public class LeftArrow2 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Left Arrow Pattern Rows = ");
		int rows = sc.nextInt();
		
		int i = 1, j;
		
		System.out.println("Printing Left Arrow Star Pattern");
		
		while(i <= rows) 
		{
			j = 1 ;
			while ( j <= rows - i ) 
			{
				System.out.print(" ");	
				j++;
			}
			j = i;
			while(j <= rows ) 
			{
				System.out.print("*");
				j++;
			}
			System.out.println();
			i++;
		}
		i = 1;
		while (i < rows ) 
		{
			j = 0 ;
			while ( j < i) 
			{
				System.out.print(" ");
				j++;
			}
			j = 0 ;
			while (j <= i ) 
			{
				System.out.print("*");
				j++;
			}
			System.out.println();
			i++;
		}
	}
}

Enter Left Arrow Pattern Rows = 7
Printing Left Arrow Star Pattern
      *******
     ******
    *****
   ****
  ***
 **
*
 **
  ***
   ****
    *****
     ******
      *******

使用 do while 循环打印左箭头星形图案的 Java 程序

package ShapePrograms;

import java.util.Scanner;

public class LeftArrow3 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Left Arrow Pattern Rows = ");
		int rows = sc.nextInt();
		
		int i = 1, j;
		
		System.out.println("Printing Left Arrow Star Pattern");
		
		do
		{
			j = 1 ;
			do
			{
				System.out.print(" ");	
			} while ( j++ <= rows - i ) ;
			j = i;
			do
			{
				System.out.print("*");
			} while(++j <= rows ) ;
			System.out.println();
		} while(++i <= rows) ;
		i = 1;
		do 
		{
			j = 0 ;
			do
			{
				System.out.print(" ");
			} while ( j++ < i) ;
			j = 0 ;
			do
			{
				System.out.print("*");

			} while (++j <= i ) ;
			System.out.println();

		} while (++i < rows );
	}
}

Enter Left Arrow Pattern Rows = 9
Printing Left Arrow Star Pattern
         *********
        ********
       *******
      ******
     *****
    ****
   ***
  **
 *
  **
   ***
    ****
     *****
      ******
       *******
        ********
         *********

在此示例中，leftArrowPattern 函数使用给定的符号打印左箭头图案。

package ShapePrograms;

import java.util.Scanner;

public class LeftArrow4 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Left Arrow Pattern Rows = ");
		int rows = sc.nextInt();
		
		System.out.print("Enter Character for Left Arrow Pattern = ");
		char ch = sc.next().charAt(0);
		
		System.out.println("Printing Left Arrow Pattern");
		leftArrowPattern(rows, ch);
	}
	
	public static void leftArrowPattern(int rows, char ch) {
		int i, j;
		for (i = 1 ; i <= rows; i++ ) 
		{
			for (j = 1 ; j <= rows - i; j++ ) 
			{
				System.out.print(" ");	
			}
			for (j = i ; j <= rows; j++ ) 
			{
				System.out.print( ch);
			}
			System.out.println();
		}
		
		for (i = 1 ; i < rows; i++ ) 
		{
			for (j = 0 ; j < i; j++ ) 
			{
				System.out.print(" ");
			}
			for (j = 0 ; j <= i; j++ ) 
			{
				System.out.print(ch);
			}
			System.out.println();
		}
	}
}

Enter Left Arrow Pattern Rows = 11
Enter Character for Left Arrow Pattern = $
Printing Left Arrow Pattern
          $$$$$$$$$$$
         $$$$$$$$$$
        $$$$$$$$$
       $$$$$$$$
      $$$$$$$
     $$$$$$
    $$$$$
   $$$$
  $$$
 $$
$
 $$
  $$$
   $$$$
    $$$$$
     $$$$$$
      $$$$$$$
       $$$$$$$$
        $$$$$$$$$
         $$$$$$$$$$
          $$$$$$$$$$$