用Java程序来打印左箭头星形图案

编写一个Java程序，使用for循环打印左箭头星形图案。在这个Java左箭头的例子中，第一个嵌套的for循环集打印左箭头的顶部部分，而另一个代码则打印左箭头的底部。

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();
	}
}

在这个Java左箭头星形图案程序中，我们用一个while循环代替了for循环。

package ShapePrograms;

import java.util.Scanner;

public class LeftArrow2 { private static Scanner scanner;

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
         *********
        ********
       *******
      ******
     *****
    ****
   ***
  **
 *
  **
   ***
    ****
     *****
      ******
       *******
        ********
         *********

在这个Java例子中，leftArrowPattern函数打印了一个给定符号的左箭头图案。

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
          $$$$$$$$$$$
         $$$$$$$$$$
        $$$$$$$$$
       $$$$$$$$
      $$$$$$$
     $$$$$$
    $$$$$
   $$$$
  $$$
 $$
$
 $$
  $$$
   $$$$
    $$$$$
     $$$$$$
      $$$$$$$
       $$$$$$$$
        $$$$$$$$$
         $$$$$$$$$$
          $$$$$$$$$$$