Merge pull request #127 from front-studium/sgoldenbird

`week28` 풀었습니다.

Author: sgoldenbird

sgoldenbird/level0/대문자와_소문자.js

@@ -0,0 +1,7 @@
+function solution(my_string) {
+  return [...my_string]
+    .map((ch) =>
+      ch === ch.toUpperCase() ? ch.toLowerCase() : ch.toUpperCase()
+    )
+    .join("");
+}

sgoldenbird/level0/인덱스_바꾸기.js

@@ -0,0 +1,5 @@
+function solution(my_string, num1, num2) {
+  const arr = [...my_string];
+  [arr[num1], arr[num2]] = [arr[num2], arr[num1]];
+  return arr.join("");
+}

sgoldenbird/level1/짝수와_홀수.js

@@ -0,0 +1,3 @@
+function solution(num) {
+  return num % 2 === 0 ? "Even" : "Odd";
+}