feat: add logic

index.js

@@ -1,3 +1,40 @@
-import { input } from '@inquirer/prompts';
+import { input } from "@inquirer/prompts";
 
-const answer = await input({ message: 'Enter your name' });
+const answer = await input({
+	message:
+		"Enter an array of string numbers containing only one letter separated by commas: (e.g. 932c, 832u32, 2344b)",
+});
+
+const array = answer.split(",");
+
+if (check_empty_array(array)) {
+	console.log([]);
+} else {
+	if (check_only_one_letter(array)) console.log(sort_by_letter(array));
+}
+
+function check_empty_array(array) {
+	if (array[0] === "") {
+		return true;
+	}
+}
+
+function check_only_one_letter(array) {
+	return array.every((element) => {
+		const letters = element.match(/[a-zA-Z]/g);
+
+		if (letters.length !== 1) {
+			return console.log("Each string must contain exactly one letter.");
+		}
+
+		return true;
+	});
+}
+
+function sort_by_letter(array) {
+	return array.sort((a, b) => {
+		const lettersA = a.match(/[a-zA-Z]/g);
+		const lettersB = b.match(/[a-zA-Z]/g);
+		return lettersA[0].localeCompare(lettersB[0]);
+	});
+}