From 7f1cb8bf62015016d4b02879b00cc7477b62c570 Mon Sep 17 00:00:00 2001
From: Aditya Purohit <adityapurohit27@gmail.com>
Date: Sun, 19 Nov 2023 09:51:44 -0400
Subject: [PATCH] refactor: decompose condition of digit checks by using extra
 method 'isNumericChar(...)' in NumberConversionUtil.

---
 src/main/java/org/json/NumberConversionUtil.java | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/main/java/org/json/NumberConversionUtil.java b/src/main/java/org/json/NumberConversionUtil.java
index d53c5e2..30ca74d 100644
--- a/src/main/java/org/json/NumberConversionUtil.java
+++ b/src/main/java/org/json/NumberConversionUtil.java
@@ -24,7 +24,7 @@ class NumberConversionUtil {
             val = "-0."+val.substring(2);
         }
         char initial = val.charAt(0);
-        if ((initial >= '0' && initial <= '9') || initial == '-' ) {
+        if ( isNumericChar(initial) || initial == '-' ) {
             // decimal representation
             if (isDecimalNotation(val)) {
                 // Use a BigDecimal all the time so we keep the original
@@ -53,13 +53,13 @@ class NumberConversionUtil {
             initial = val.charAt(0);
             if(initial == '0' && val.length() > 1) {
                 char at1 = val.charAt(1);
-                if(at1 >= '0' && at1 <= '9') {
+                if(isNumericChar(at1)) {
                     throw new NumberFormatException("val ["+input+"] is not a valid number.");
                 }
             } else if (initial == '-' && val.length() > 2) {
                 char at1 = val.charAt(1);
                 char at2 = val.charAt(2);
-                if(at1 == '0' && at2 >= '0' && at2 <= '9') {
+                if(at1 == '0' && isNumericChar(at2)) {
                     throw new NumberFormatException("val ["+input+"] is not a valid number.");
                 }
             }
@@ -83,6 +83,16 @@ class NumberConversionUtil {
         throw new NumberFormatException("val ["+input+"] is not a valid number.");
     }
 
+    /**
+     * Checks if the character is a numeric digit ('0' to '9').
+     *
+     * @param c The character to be checked.
+     * @return true if the character is a numeric digit, false otherwise.
+     */
+    private static boolean isNumericChar(char c) {
+        return (c >= '0' && c <= '9');
+    }
+
     /**
      * Checks if the value could be considered a number in decimal number system.
      * @param value