IGCSE Computer Science Paper 2 Definitions Worksheet: 8.2 Arrays (Modules 459–468)
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Key terms
Write what each term means, in your own words.
1
FOR Index ← 0 TO 29
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INPUT Name[Index]
3
OUTPUT StudentNames[Index]
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Total ← Total + Marks[Index]
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IF Marks[Index] >= 50 THEN Count ← Count + 1
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Largest ← Marks[1]
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linear search
8
parallel arrays
9
trace table
10
2D array
Answer Key
IGCSE Computer Science Paper 2 · Modules 459–468 · Student wording will vary for definitions
1FOR Index ← 0 TO 29 — For ARRAY[0:29], the loop must start at the lower bound 0 and end at the upper bound 29. It then visits all 30 elements and never goes outside the array.
2INPUT Name[Index] — Inside a FOR loop, INPUT Name[Index] stores each value the user types into the next array element, because Index changes every time the loop repeats.
3OUTPUT StudentNames[Index] — Inside a FOR loop, this line displays every element of the array in order. Index changes on each pass, so each pass outputs the next element, from the lower bound to the upper bound.
4Total ← Total + Marks[Index] — Adds the current element to the running total on each loop pass. Set Total ← 0 before the loop first, or the answer will be wrong. Divide by the number of elements for the average.
5IF Marks[Index] >= 50 THEN Count ← Count + 1 — An IF inside the loop tests each element and adds 1 to Count when true. Set Count to 0 before the loop. A counter counts matches; a total adds up values.
6Largest ← Marks[1] — Start by assuming the first element is the largest, then compare every other element and replace Largest when a bigger one is found.
7linear search — A loop checks every element against the wanted value. On a match, set Found to TRUE and record the index. If Found is still FALSE at the end, OUTPUT a not found message.
8parallel arrays — Two or more arrays of the same size where the same index holds related data, e.g. StudentNames[3] and Marks[3] both describe the same student.
9trace table — A table that records the loop variable, index and array contents after each pass of a loop, so you can predict the final OUTPUT and spot errors such as off-by-one.
102D array — A table of rows and columns held in one variable. Each element needs two indexes: the first is the row (across), the second is the column (down), e.g. Marks[2, 3].