added solution of problem1

Author: arifuddincoder

problem1-reverse-string.js

@@ -5,3 +5,11 @@
 
 // Input: "hello"
 // Output: "olleh"
+
+const str = "hello";
+
+const revStr = (str) => {
+	return str.split("").reverse().join("");
+};
+
+console.log(revStr(str));