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(a) What
is the effect of adding the keyword static to a local variable in a procedure? |
[2] |
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the
various retains its value between function calls, |
[1] |
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and exists
throughout the lifetime of the program execution. |
[1] |
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(b) Given
the following program: |
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Result of tracing the add_val procedure: |
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(i) What is the output of the
program when it is executed? |
[4] |
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Result of
tracing the program execution: |
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Value is 5
and result is 47 |
[1] |
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Value is 1
and result is 1 |
[1] |
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Value is 6
and result is 7 |
[1] |
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Value is
21 and result is 28 |
[1] |
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(ii) What would the output be if
the static keyboard were removed? |
[4] |
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Result of
tracing the program when the static keyword is removed: |
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Value is 5
and result is 47 |
[1] |
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Value is 1
and result is 1 |
[1] |
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Value is 6
and result is 48 |
[1] |
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Value is
21 and result is 63 |
[1] |
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If
the students omit the Value is . . . and result is . . ., but give the correct numerical
values of value and result, award the marks as above. |
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(c) Trace
the output produced when the following C programs are executed: |
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Output
of two C programs: |
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(i) Program 1: |
[4] |
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x.a = 42 |
[1] |
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x.p = 1969 |
[1] |
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y.a = 1998 |
[1] |
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y.p = 1998 |
[1] |
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Award one mark
for each of numbers in the output above. Do not deduct marks if the answers do not include
the accompanying text such as x.a =. If the values for y.a and y.b are 1997, award on
mark, instead of zero, for the two lines. |
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[4
marks] |
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(ii) Program 2: |
[6] |
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77 &
42 = 8 |
[1] |
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77 | 42 =
111 |
[1] |
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77 ~
42 = 103 |
[1] |
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4 <<
2 = 16 |
[1] |
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16
>> 2 = 4 |
[1] |
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~(-2)
= 1 |
[1] |
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Award one mark
for each line of output. Do not deduct marks if the students just list the size results
without the text to the left of the =. |
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[6
marks] |
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