In Java, how would I code a pyramid of asterisks by using nested for loops?

I am working on an assignment where I have to use nested loops to program a pyramid of asterisks that is on its side.
The output of this program should look like this:

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

When I run my program, it only displays the final four lines of the code. I don't know why the first three don't show up.
Here is my code:

public class Main
{
	public static void main(String[] args) {
		
		for(int a = 0; a < 8; a++) //1
		{
		    if(a < 4){
		        for(int b = a; b < 4; b++)
		        {
		            System.out.print("*");
		        }
		        
		    }
		    if(a >= 4)
		        for(int c = a; c < 4; c++)
		        {  
		            System.out.print("*");
		        }
		    
		    System.out.println();
		} //loop 1
		
	}
}

And here is my output:

****
***
**
*

(There is some empty space after the output that I did not include. This is caused by the outer for loop iterating eight times.) How would I make my program correctly display all of the code, instead of just the last four lines?

Any help would be greatly appreciated.

There are several mistakes in your logic:

1. Since you only need 7 rows, the first loop should iterate until a < 7
2. In the first 3 rows, your nested loop should iterate from 0 to a
3. After that, the other nested loop should go from a to 7
4. It is better to use if-else instead of two if statements

Here is the complete solution that I tested:

for(int a = 0; a < 7; a++) {
     if(a < 4){
          for(int b = 0; b <= a; b++)
               System.out.print("*");
     }else {
          for(int c = a; c < 7; c++)
               System.out.print("*");
     }
     System.out.println();
}

Output:

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

EDIT:

As mentioned in the comments, you can also split the outer loop into two parts in order to remove the conditions as follows:

for(int a = 0; a < 4; a++) {
     for(int b = 0; b <= a; b++)
          System.out.print("*");
     System.out.println();
}
for(int a = 4; a <= 7; a++) {
	 for(int b = a; b < 7; b++)
	   	  System.out.print("*");
	 System.out.println();
}

You're close. Try something like this:

int size = 4;
		
for(int line = 1; line < size * 2; line++) {
  if(line <= size) {
    for(int i = 0; i < line; i++) {
      System.out.print("*");
    }
  }
  else {
    for(int i = 0; i < size * 2 - line; i++) {
      System.out.print("*");
    }
  }
  System.out.println();
}