May 7, 2009 · An undeclared variable does not exist in Javascript memory whereas a declared one does and can be set to undefined. The difference is caused by Javascript design confusion.

Aug 18, 2021 · If the variable name which is being accessed doesn’t exist in memory space then it would be not defined, and if exists in memory space but hasn’t been assigned any value till now, then it would be undefined.

Jul 28, 2011 · What's the difference between something being undefined and something not being defined in Javascript? For instance, trying to access a property for an object (effectively, trying to access a variable) that isn't defined will return undefined. But …

Oct 22, 2018 · There are certain cases when undefined value is returned in javascript as follows:- 1)Whenever we declare a variable without assigning any value to it, javascript implicitly assigns its value as...

What is “Not Defined”? “Not defined” refers to a variable that hasn’t been allocated memory. On the other hand, undefined does not mean empty; it is a special keyword in JavaScript.

Aug 17, 2024 · Diffrences Between Undefined and Not Defined: In this tutorial we will discuss about undefined and not defined, in Javascript undefined refers to the absence of a value and the not defined refers to th...

Sep 2, 2024 · Ever stumbled upon JavaScript errors and wondered what undefined and not defined really mean? Discover the key differences between these common issues, understand their causes, and learn...

In JavaScript, undefined is a primitive (most basic data types in JavaScript) value automatically assigned to variables that are declared but not initialised.

Sep 22, 2024 · TLDR: undefined is a primitive value that indicates the absence of a value assigned to a variable. Not defined just means that the variable hasn’t actually been created.

Aug 1, 2023 · The states of undefined and not defined in JavaScript are fundamental concepts tied to the language's two-phase execution model. Understanding these states and the underlying memory...