Programming exam tips

Exam tips

• Match the type to the data

  When asked to select a data type, identify the kind of value first: whole number, fractional number, logical value, single character, text, date/time, address, grouped fields or collection.

  The specification tests whether each listed data type is understood and used appropriately.

• Trace in execution order

  For code-tracing questions, write down the value of important variables after each assignment, selection and iteration.

  Following sequence explicitly reduces errors when a variable is changed more than once or when a loop condition is tested repeatedly.

• Show the operation before calculating

  Identify whether the expression requires real division, integer division, a remainder, exponentiation, rounding or truncation before working out its value.

  Several arithmetic operations can use the same numbers but produce different results, so identifying the operator helps prevent avoidable errors.

• Check boundary values

  Pay close attention to whether an operator includes equality. Operators <= and >= include the boundary value, whereas < and > do not.

  Testing a value exactly at the boundary helps distinguish the paired operators and prevents incorrect True or False answers.

• Test every Boolean combination

  For two Boolean inputs, check True/True, True/False, False/True and False/False when tracing an expression.

  Considering all four combinations helps distinguish AND, OR and XOR and reduces errors when evaluating expressions.

• Link advantages to the situation

  When asked for advantages of named constants, explain both why the name helps the reader and how one declaration can make updating the value easier.

  A developed explanation gains more credit than simply stating that constants are useful or easier to maintain.

• Track the data type

  For every string-handling step, identify whether the value is currently a string, integer, float, character, or character code.

  This helps you decide when a string conversion operation is needed, especially before arithmetic or concatenation.

• Check both endpoints

  Before writing the random-number statement, identify the smallest and largest values that must be possible.

  This helps you select the correct lower and upper arguments and avoid an off-by-one error.

• Name the roles of both blocks

  When explaining Python exception handling, state that try contains code that might cause an exception and except contains the response if it occurs.

  This directly addresses how exception handling is used and helps distinguish the two parts of the structure.

• Link each advantage to its effect

  Do not just list an advantage such as reduced duplication. Explain how writing the code once and calling it when needed produces that advantage.

  Explanations are more likely to receive full credit when they connect the use of a named code block to a specific benefit.