magic number

名词 Noun

(nuclear physics) The number of neutrons or protons in nuclei which are required to fill the major quantum shells, and thus produce exceptionally stable nuclei: 2, 8, 20, 28, 50, 82 and 126.
(sports) A metric used to determine a team's required performance to make the playoffs.
(computing) A number which is manually entered into source code, rather than defined somewhere as a named constant; especially one which is arbitrary or lacks explanation.
(computing) A sentinel value which cannot occur in normal use, typically used as a placeholder (e.g. a fictitious date such as 2000-02-32).
(computing) A hash code, such as those used by some webmail servers to keep track of sessions.
(computing) A number or pattern in a binary file that identifies the filetype.