1、 In the context of mathematics, the term undefined is adopted when an operation doesn’t have any meaning or result under its domain. It's noteworthy that "undefined" encompasses vagueness - a term that encapsulates shifting sands of potentiality, the unknown and the unformed, bubbling within the cauldron of creation and destruction， On top of all, undefined embodies the promises and pitfalls of the scholar, the mathematician, the programmer and the philosopher and continues to challenge the quest for precision and certainty in each field. This term has particular powerful implications within the realm of mathematics and computing.
2、 For example, the division of any number by zero is considered to be undefined， In computing, meanwhile, it refers to a variable that has been declared but not assigned any value, thus, it cannot be called or used."Undefined" carries a multitude of meanings throughout different disciplines; however, its essence lies within its unassigned value or state. Another interesting concept is 'undefined behavior,' a term commonly used in computer programming, especially in C/C++ programming languages, that refers to the erratic and potentially harmful output as a result of anomalous instructions or violations within the underlying system’s regulations. In set theory, undefined is indicative of an element that does not belong in a particular prescribed set， A more obscure example resides in the specification of JavaScript, where ‘undefined’ represents a primitive value automatically assigned to variables that have just been declared, and no value has been explicitly assigned.
