Learning Intention I will learn how to use

Learning Intention • I will learn how to use an array to store data in a program.

1. 2. 3. 4. 5. 6. Analysis Design Implementation Testing Documentation Evaluation

How would you store the names of all pupils in the class in a program? …

Array • An array is a data structure (a list of data items). • All the items have the same data type. e. g. in VB to store 20 names in an array: Dim names(20) As String

Array • Each item in an array is called an element. • Each element is identified by the variable name and an index (number) which identifies the position of the element in the array.

Think of Excel What is the value in A 3? What is the value in B 5?

Excel (modified) names ages What is the value in names(7)? What is the value in ages(10)?

SQA Reference Language for Array • With data (so can work out the data type): e. g. DECLARE some. Vals INITIALLY [4, 6, 1] • Without data (so must state data type): e. g. DECLARE new. Vals AS ARRAY OF STRING INITIALLY []

SQA Reference Language for Array 1. 2. 3. 4. 5. 6. DECLARE all. Costs INITIALLY [ 7, 3, 5, 7, 9 ] SET total TO 0 FOR index FROM 1 TO 4 DO SET total TO total + all. Costs(index) END FOR SEND total TO DISPLAY

SQA Reference Language for Array 1. 2. 3. 4. 5. 6. DECLARE all. Costs INITIALLY [3, 5, 2] SET total TO 0 FOR EACH cost FROM all. Costs DO SET total TO total + cost END FOR EACH SEND total TO DISPLAY

Array in VB

Programming Tasks • Complete the programming tasks on pages 76 -79 • Extension Task Set 7

Success Criteria • I can use arrays to store data.