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Type Rule 10.4 A non-void function (except main) must have a Return statement, whose Expression must be the same type as the function. Type Rule 10.5 A void function cannot have a Return. Type Rule 10.6 Every Call Statement must identify a void function, and every Call Expression must identify a non-void function. Type Rule 10.7 Every Call must ...

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A system is a purposeful collection of inter-related components working together to achieve some common objective. A system may include software, mechanical, electrical and electronic hardware and be operated by people. System components are dependent on other system components. The properties and behaviour of system components are inextricabl...

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Sequential access files allow sequential operations Read, write, and search Efficient for report writing Searches are not efficient because an average of 50% of records have to be accessed Two versions Ordered unordered

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Factors to consider for array versus database are: 1. Execution speed. 2. Volume of data. 3. Clarity of the code that accomplishes the task. As RAM gets less expensive, the distinction between databases and arrays gets less clear.

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The system requirements are likely to change while the system is being developed because the environment is changing. Therefore a delivered system won't meet its requirements! Systems are tightly coupled with their environment. When a system is installed in an environment it changes that environment and therefore changes the system requiremen...

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Query operations should not be redefined Methods that redefine inherited ones should only restrict the semantics of the inherited ones The underlying semantics of the inherited method should never be changed The signature (argument list) of the inherited method should never be changed

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A stack of activation records. Each new call pushes an activation record, and each completing call pops the topmost one. So, the topmost record is the most recent call, and the stack has all active calls at any run-time moment. For example, consider the call factorial(3). This places one activation record onto the stack and generates a sec...

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XML Schemas Rules that define legal elements, tags, and content. Used to determine the validity of a document. Industry specific XML schemas are being developed.

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Verification:  "Are we building the product right”. The software should conform to its specification. Validation: "Are we building the right product”. The software should do what the user really requires.

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Perl: implicit conversions, distinct operators “2” < “10” : true – numeric comparison “2” lt “10” : false – string comparison 2 lt “10” : false – 2 converted to “2” Python: explicit conversions required “2” < “10” : false – string comparison 2 < “10” : error

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