1、 It's an astounding reminder of the infinity inherent in numbers, of the finiteness of computing power, and of the complexity cloaked in apparent simplicity. Moreover, in algebra and calculus courses, students learn that certain forms, such as 0/0 or ∞/∞, are indeterminate forms — a type of undefined mathematical expression， So, 'Undefined' is not merely an error message or an exception thrown on console, it's an integral concept in the field of computation and mathematics, emphasizing the limitations of operations and the necessity to handle exceptions.
2、Undefined, in the realm of mathematics, computer science, and related domains, represents a condition or state that is not determinate, fixed, or clearly expressed， Undefined has a particularly distinctive role in different areas of computation and mathematical theories. In these contexts, any attempts to manipulate or call upon undefined variables can cause runtime errors or unanticipated results, essentially breaking a program's flow, making it an essential concept in bug prevention and resolution scenarios. In Javascript and many other high-level programming languages, "undefined" is a variable that has been declared but has not been assigned a value, or not defined.
3、 An undefined value or variable typically dictates an error, an ambiguous state, or a result that doesn't exist or cannot be accurately computed， Probabilities which give equal chances to infinite outcomes are another instance of undefinedness. In mathematics, it refers to situations where a number is divided by zero, a circumstance that is undetermined by axioms of arithmetic.
