refactor: add array check

mate-academy · Aug 3, 2023 · eb94bdb · eb94bdb
1 parent ca9339f
commit eb94bdb
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/src/arrayMethodJoin.js b/src/arrayMethodJoin.js
@@ -9,6 +9,11 @@ const isNotIgnoredEl = (el) => ![null, undefined].includes(el);
 function applyCustomJoin() {
   [].__proto__.join2 = function(separator = ',') {
     const currentArray = this;
+
+    if (!(currentArray instanceof Array)) {
+      return '';
+    }
+
     const INDEX_OF_LAST_ELEMENT = currentArray.length - 1;
 
     let concatedString = '';