I am trying to display a diamond of asterisks using nested for loops.
Here is my code so far:
public          
        Try this code. Using Math.abs will be a lot simple.
import java.util.Scanner;
public class MakeDiamond {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (true) {
            System.out.println("Let's Creat Diamonds");
            System.out.println("If number increases Diamonds gets bigger. " +
                    "Please input number lager than 1 : ");
            int user_input = sc.nextInt(); //gets user's input
            System.out.println("");
            int x = user_input;
            int front_space = -5;
            for (int i = 0; i < 2 * user_input + 1; i++) {
                for (int a = front_space; a < Math.abs(i - user_input); a++) {
                    System.out.print("    ");
                }
                if (i < user_input + 1) {
                    for (int b = 0; b < 2 * i + 1; b++) {
                        System.out.print("*  ");
                    }
                } else if (i > user_input) {
                    for (int c = 0; c < 2 * x - 1; c++) {
                        System.out.print("*  ");
                    }
                    x--;
                }
                System.out.print('\n');
            }
            System.out.println("\nRun Again? 1 = Run,  2 = Exit : ");
            int restart = sc.nextInt();
            System.out.println("");
            if (restart == 2) {
                System.out.println("Exit the Program.");
                System.exit(0);
                sc.close();
            }
        }
    }
}