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Data Structures [1]. CP1. Arrays. All data must be the same data type…. Eg . (Daily sales figures for John - to nearest £) Mon 240 Tue 230 Wed 180 Thu 270 Fri 120 (All of data type Integer ). In Visual Basic…. Dim Sales(5) As Integer
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Data Structures [1] CP1 Data Structures 1.
Arrays • All data must be the same data type…. • Eg. (Daily sales figures for John - to nearest £) Mon 240 Tue 230 Wed 180 Thu 270 Fri 120 (All of data type Integer) Data Structures 1.
In Visual Basic… Dim Sales(5) As Integer A one-dimensional array has one subscript to identify the element of the array. Eg. Mon 240 Tue 230 Wed 180 Thu 270 Fri 120 • Sales(4) Data Structures 1.
Two-dimensional Arrays • Data must be the same type. • A two-dimensional array has 2 subscripts. Eg. Sales figures for John, Mary and Sue: John Mary Sue Mon240 420 140 Tue230 380 190 Wed180 400 210 Thu270 360 240 Fri120 320 190 Sales(4,2) Data Structures 1.
Three-dimensional Arrays • Data must be the same type. • A two-dimensional array has 3 subscripts. Eg. Sales figures for John, Mary and Sue for each of three different items… Item 1 John Mary Sue Mon240 420 140 Tue230 380 190 Wed180 400 210 Thu270 360 240 Fri120 320 190 Item 2 John Mary Sue Mon440 440 120 Tue530 380 390 Wed480 440 280 Thu670 365 540 Fri150 310 490 Item 3 John Mary Sue Mon210 430 120 Tue130 280 190 Wed120 100 220 Thu270 320 143 Fri120 220 295 Data Structures 1.
…and YES! In programming you can have Arrays with more than three dimensions… • All data must be of the same data type • An n-dimensional array would use n subscripts to identify each element. Data Structures 1.
Records • Data may be of different types • Eg. (Name, Form, DOB, Exam mark) John Smith 12 T 12/04/85 65 (Text strings, a date and a number) Data Structures 1.
In Visual Basic… Structure PupilType Dim PupilName As String Dim Form As String Dim DOB As Date Dim ExamMark As Integer End Structure Data Structures 1.
Structure PupilType Dim PupilName As String Dim Form As String Dim DOB As Date Dim ExamMark As Integer End Structure A variable Pupil can be declared as being of type PupilType, and the fields assigned… Dim Pupil As PupilType Pupil.PupilName = “John Smith” Pupil.Form = “12T” Pupil.DOB=“12.04.85” Pupil.ExamMark = 65 Data Structures 1.
Arrays of Records An array of records is sometimes called a TABLE. Each record has a subscript…If this table was called Markbook, then Markbook(4).ExamMark is 44. Data Structures 1.