indirection

indirection

Not direct. Indirection provides a way of accessing instructions, routines and objects when their physical location is constantly changing. The initial routine points to some place, and, using hardware and/or software, that place points to some other place. There can be multiple levels of indirection. For example, point to A, which points to B, which points to C. See indirect addressing.

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(programming)

indirection - Manipulating data via its address. Indirection is a powerful and general programming technique. It can be used for example to process data stored in a sequence of consecutive memory locations by maintaining a pointer to the current item and incrementing it to point to the next item. Indirection is supported at the machine language level by indirect addressing. Many processor and operating system architectures use vectors which are also an instance of indirection, being locations which hold the address of a routine to handle a particular event. The event handler can be changed simply by pointing the vector at a new piece of code. C includes operators "&" which returns the address of a variable and its inverse "*" which returns the variable at a given address.