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How to write java program for CROSS STARS pattern using NESTED LOOP?

• I want to work on a java program that reproduces a cross of stars such that: The user enters the number of stars to print (same number of stars horizontally and vertically). The ...show more

• Answer:

  You can spend 2 weeks trying ot get the loops to count. Can u use arrays? public class Diamonds_2 { static private String[] d_array; public static void main(String[] args) throws Exception { System.out.println("Enter an odd number, please: "); java.util.Scanner sc = new java.util.Scanner(System.in); boolean run = true; while (run) { int size = sc.nextInt(); if (size % 2 != 1 || size == 1) { System.out.println("Please, an ODD number > 1: "); } else { d_array = new String[size]; StringBuilder sb = new StringBuilder(); int midRow = size / 2 + 1; // make the full row for (int i = 0; i < size; i++) { sb.append("*"); } char cs = ' '; d_array[midRow - 1] = sb.toString(); // arrays zero-based int fLetter = 0; int lLetter = size - 1; int i = 1; // now we eat the StringBuilder at both ends // that is, the columns // load the row above, and the row below // the middle row as we eat the "*"s while (i < midRow) { sb.setCharAt(fLetter, cs); sb.setCharAt(lLetter, cs); d_array[midRow - 1 - i] = sb.toString(); d_array[midRow - 1 + i] = sb.toString(); fLetter++; lLetter--; i++; } // end while -- load d_array } // end else run = false; String msg = "If you know calculus\nthis can be done\n"; msg += "with one \"for loop\", \nand 2 lines,\n"; msg += "spaces.substring(0,x); stars.substring(0,y);"; System.out.printf("%s%n%n", msg); System.out.println("but here it is: the sane way...\n"); for (int i = 0; i < d_array.length; i++) { System.out.println(d_array[i]); } // end for loop to print } // end while -- scanner/console doSparkle(); } // end main static void doSparkle() { int midRow = d_array.length / 2; int midCol = d_array[0].length() / 2 + 1; String slash = "\\/"; char[] slashes = slash.toCharArray(); int leftSlash = midCol-1; int rightSlash = midCol; int i = 1; // System.out.printf("midRow: %d, midCol: %d, leftSlash: %d, rightSlash: %d, i: %d%n%n", // midRow, midCol, leftSlash, rightSlash, i); while (i <= midRow ) { StringBuilder sb1 = new StringBuilder(d_array[midRow - i]); StringBuilder sb2 = new StringBuilder(d_array[midRow + i]); sb1.setCharAt(leftSlash, slashes[0]); sb2.setCharAt(leftSlash, slashes[1]); sb1.setCharAt(rightSlash, slashes[1]); sb2.setCharAt(rightSlash, slashes[0]); d_array[midRow - i] = sb1.toString(); d_array[midRow + i] = sb2.toString(); leftSlash--; rightSlash++; i++; } // end while printArr(); } // end doSparkle static void printArr() { for (int i = 0; i < d_array.length; i++) { System.out.println(d_array[i]); } // end for loop to print } } // end class