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In the context of computer programming, magic is an informal term for abstraction - it is used to describe code that handles complex tasks while hiding that complexity to present a simple interface. The term is somewhat tongue-in-cheek and carries bad connotations, implying that the true behavior of the code is not immediately apparent. For example, Perl's polymorphic typing and closure mechanisms are often called "magic". The term implies that the hidden complexity is at least in principle understandable, in contrast to black magic and deep magic, which describe arcane techniques that are deliberately hidden or extremely difficult to understand. The action of such abstractions is described as being done "automagically", a portmanteau of "automatically" and "magically". ==Referential opacity== (詳細はprocedures which make calculations based on data not clearly provided to them, by accessing other modules, memory positions or global variables that they are not supposed to (in other words, they are not referentially transparent). According to most recent software architecture models, even when using structured programming, it is usually preferred to make each function behave the same way every time the same arguments are passed to it, therefore following one of the basic principles of functional programming. When a function breaks this rule, it is often said to contain "magic". A simplified example of negative magic is the following code in PHP: function Magic() $somevariable = true; Magic(); While the code above is clear and maintainable, if it is seen in a large project, it is often hard to understand where the function Magic() gets its value from. It is preferred to write that code using the following concept:function noMagic($myvariable) $somevariable = true; noMagic($somevariable); 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Magic (programming)」の詳細全文を読む スポンサード リンク
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