A-level Computing/AQA/Paper 1/Theory of computation/Composition

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Composition is putting pieces back together the opposite of the decomposition

In computing there are 2 types of composition: (1) Object Composition and (2) Function Composition

Generally speeking, both types of composition involve incorporating multiple objects/functions to create a single, more complex object/function. The process of determining objects/functions to be 'composed' is part of the abstraction process (see computational thinking), and could be the direct result of decomposition (see decomposition). This is a requred process of the Software Development Lifecycle, but can be applied to any other activity where Computational Thinking is applied.

The following function could be decomposed:

Function PrintCustomerBankAccounts

into

Function PrintCustomerSavingsAccount

Function PrintCustomerBankAccount

if there were different attributes (see attributes) for the 2 account types.

However it may be determined