From 07b7a7b7cd48df991bd27cbfe09b3a0c69b8f2a9 Mon Sep 17 00:00:00 2001
From: Tlekbai Ali <ali.tlekbai@gmail.com>
Date: Wed, 3 Jun 2020 13:12:12 +0600
Subject: [PATCH] Update index-of.en.md

Add clarification
---
 subjects/index-of.en.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/subjects/index-of.en.md b/subjects/index-of.en.md
index 8dd4cf215..bbd5ebb6a 100644
--- a/subjects/index-of.en.md
+++ b/subjects/index-of.en.md
@@ -9,6 +9,7 @@ Create 3 functions:
 
 > If a value is not found, the returned index is -1
 
+> functions should have array element as first argument
 > `indexOf` and `lastIndexOf` takes an additionnal `fromIndex` argument
 > that allow you to begin searching from a specific index.