From 885ae09ccef7ec7e513ebbaea34ef28ac87374aa Mon Sep 17 00:00:00 2001 From: Vashisth Bhushan Date: Wed, 12 Jun 2019 00:59:53 +0530 Subject: [PATCH] Update README.md --- README.md | 1 + 1 file changed, 1 insertion(+) diff --git a/README.md b/README.md index 4d35cb3..475fd6f 100644 --- a/README.md +++ b/README.md @@ -13,6 +13,7 @@ It's a book about frontend interview question. We hope that it will help all jav ### Answer + In JavaScript if you try to use a variable that doesn't exist and has not been declared, then JavaScript will throw an error `var name is not defined` and the script will stop executing thereafter. But If you use `typeof undeclared_variable` then it will return `undefined`. Before starting further discussion let's understand the difference between declaration and definition.