Test

src/formatDate.js

@@ -3,12 +3,49 @@
 /**
  * @param {string} date
  * @param {string[]} fromFormat
- * @param {string[]} toFormat
+ * @param {string[]} toFormat.
  *
  * @returns {string}
  */
 function formatDate(date, fromFormat, toFormat) {
-  // write code here
+  const splitSeparator = fromFormat[fromFormat.length - 1];
+  const splitDate = date.split(splitSeparator);
+
+  const joinSeparator = toFormat[toFormat.length - 1];
+
+  // variables of index date fromFormate
+  const fromYYYY = fromFormat.includes('YY')
+    ? fromFormat.indexOf('YY')
+    : fromFormat.indexOf('YYYY');
+  const fromMM = fromFormat.indexOf('MM');
+  const fromDD = fromFormat.indexOf('DD');
+
+  // variables of index date toFormate
+  const toYYYY = toFormat.includes('YY')
+    ? toFormat.indexOf('YY')
+    : toFormat.indexOf('YYYY');
+  const toMM = toFormat.indexOf('MM');
+  const toDD = toFormat.indexOf('DD');
+
+  if (fromFormat[fromYYYY].length > toFormat[toYYYY].length) {
+    splitDate[fromYYYY] = splitDate[fromYYYY].slice(2);
+  }
+
+  if (fromFormat[fromYYYY].length < toFormat[toYYYY].length) {
+    if (+splitDate[fromYYYY] < 30) {
+      splitDate[fromYYYY] = '20' + splitDate[fromYYYY];
+    } else {
+      splitDate[fromYYYY] = '19' + splitDate[fromYYYY];
+    }
+  }
+
+  const result = [];
+
+  result[toYYYY] = splitDate[fromYYYY];
+  result[toMM] = splitDate[fromMM];
+  result[toDD] = splitDate[fromDD];
+
+  return result.join(joinSeparator);
 }
 
 module.exports = formatDate;