Added format rupiah

apps/frontend/src/utils/formatRupiah.ts

@@ -0,0 +1,18 @@
+/**
+ * Formats a number into the Indonesian Rupiah currency format.
+ * 
+ * @param value - The number to be formatted.
+ * @returns A string representing the formatted Rupiah value.
+ * 
+ * * @example
+ * ```
+ * const rupiahValue = formatRupiah(123456789);
+ * console.log(rupiahValue); // Output: "Rp 123.456.789"
+ * ```
+ */
+function formatRupiah(value: number): string {
+    const formatted = value.toString().replace(/\B(?=(\d{3})+(?!\d))/g, '.');
+    return `Rp ${formatted}`;
+}
+
+export default formatRupiah