'''Once and only once''' is a rule of thumb in [[software development]]. A function should be defined in only one place, because it is easier to maintain that way. Even a few lines of code or one complex formula is better wrapped into a method or subroutine.
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'''Once and only once'''
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It is a rule of thumb in [[agile software development]]. A function should be defined in only one place, because it is easier to maintain that way. Even a few lines of code or one complex formula is better wrapped into a method or subroutine.