Undefined is a term used in programming to describe a value that has not been assigned or defined. It is commonly used to represent the absence of a value when no other value can be determined. In JavaScript, undefined is a keyword that indicates that a variable or object does not have a value assigned to it. When trying to access an undefined variable, an error will usually occur.
Why does undefined exist?
Undefined exists in order to provide information about the state of a variable or object
Undefined
Undefined is a special data type that is used to indicate the absence of a value. It is often used when a variable or parameter has been declared, but no value has been assigned to it yet. In programming languages, undefined can also refer to an uninitialized variable or an object with no properties.
In JavaScript, the typeof operator returns “undefined” for variables that have not been assigned a value. This can be useful when checking for the presence of a variable before using it in an expression. For example, if
