### What is Undefined

Undefined is also a data type in JavaScript just like the `null`. When a variable is created or declared without assigning any value to it, then the value of the variable will be set as `undefined` by default.

So, undefined variables can also be declared using the `undefined` keyword.


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The syntax of the JavaScript programming language is the set of rules that defines how a JavaScript program will be written and interpreted (by both the runtime system and by human readers).

JavaScript is dynamically typed (also called loosely typed) scripting language. That is, in javascript variables can receive different data types over time. Datatypes are basically typed of data that can be used and manipulated in a program.

Undefined

What is Undefined

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