From 43e2209909c357ba57db5a350868d697889b9a40 Mon Sep 17 00:00:00 2001
From: Hidemichi Shimura <hidemichi.shimura@gmail.com>
Date: Tue, 17 Jan 2023 07:58:17 -0800
Subject: [PATCH 1/2] solve 1556. Thousand Separator

---
 1556.thousand-separator.js | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 1556.thousand-separator.js

diff --git a/1556.thousand-separator.js b/1556.thousand-separator.js
new file mode 100644
index 00000000..d7e6fda6
--- /dev/null
+++ b/1556.thousand-separator.js
@@ -0,0 +1,21 @@
+/* URL of this problem
+ * https://leetcode.com/problems/thousand-separator/description/
+ *
+ * @param {number} n
+ * @return {string}
+ */
+
+var thousandSeparator = function (n) {
+  let str = n.toString();
+  const SeparatatedStr = [];
+
+  // Extract the last 3 digits and add them to SeparatatedStr in an order by occurrence
+  while (str.length > 0) {
+    SeparatatedStr.unshift(str.substring(str.length - 3, str.length));
+    str = str.substring(0, str.length - 3);
+  }
+
+  return SeparatatedStr.join(".");
+};
+
+module.exports = thousandSeparator;

From 9bfb98f2cc8aec0467c7238c5841eed9ff67c059 Mon Sep 17 00:00:00 2001
From: Hidemichi Shimura <hidemichi.shimura@gmail.com>
Date: Tue, 17 Jan 2023 07:58:39 -0800
Subject: [PATCH 2/2] test function thousandSeparator

---
 thousandSeparator.test.js | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 thousandSeparator.test.js

diff --git a/thousandSeparator.test.js b/thousandSeparator.test.js
new file mode 100644
index 00000000..dc9c24c9
--- /dev/null
+++ b/thousandSeparator.test.js
@@ -0,0 +1,13 @@
+const thousandSeparator = require("../jest-test/1556.thousand-separator");
+
+test("Return a string wihtout any separator dot", () => {
+  expect(thousandSeparator(987)).toBe("987");
+});
+
+test("Return a string seperated by dots", () => {
+  expect(thousandSeparator(1234)).toBe("1.234");
+});
+
+test("Return a string of 0s seperated by dots if the input n consists only of 0", () => {
+  expect(thousandSeparator(0000000)).toBe("0.000.000");
+});