1-D arrays

A list of the same type

• An array holds a fixed number of values of one type.
• The guide's lower bound is 1 unless a question says otherwise.
• One index, in square brackets, picks an element.

DECLARE Score : ARRAY[1:5] OF INTEGER
Score[1] ← 4
Score[2] ← 8
OUTPUT Score[1]

A loop visits every cell

• A FOR loop from the lower bound to the upper bound is how you fill or read the array.

DECLARE Score : ARRAY[1:3] OF INTEGER
Score[1] ← 4
Score[2] ← 8
Score[3] ← 6
DECLARE Total : INTEGER
Total ← 0
FOR I ← 1 TO 3
  Total ← Total + Score[I]
NEXT I
OUTPUT Total

Watch out

• Score[1] is the first cell when the array was declared [1:5].
• The index can be an expression: Score[I + 1].

Common mistakes

• Declare the array before you store into a cell.
• The index must stay inside the declared bounds.

Now you try

• Store three numbers and total them.