Arrays in BASIC

BASIC Programming

An array is a set of like variables arranged in sequence identified by their subscripts. The subscripted variable names are similar to simple variable names except that they are3 followed by a subscript. The subscript must be an integer and must be enclosed in parentheses. For example A(4), A$(5).

Program

10 Read Items $ (1), Items $ (2), Items $ (3)

20 Data Pen, Book, Pencil

30 Print Items $ (1), Items $ (2), Items $(3)

40 End

Output

Pen        Book      Pencil

Array using a For…Next Loop

Program

10 For i=1 to 3

20 Read Items $ (i)

30 Next i

40 Data Pen, Book, Pencil

50 For b= 1 to 3

60 Print Items $ (b)

70 Next b

80 End

Output

Pen

Book

Pencil

Dim statement

Dim is a short for dimension. Dim statement is used to declare an array of more than 10 subscripts.

Program

10 For i=1 to 12

20 Read Names $ (i)

30 Next i

40 Data Masood, Imran, Rahim Jan, Iltiaz, Zaid, Chakar, Adil, Kamran, Sohail, Aman, Amir, Javid

 50 For b= 1 to 12

60 Print names $ (b)

70 Next b

80 End

Output

Masood

Imran

Rahim Jan

Iltiaz

Zaid

Chakar

Adil

Kamran

Sohail

Aman

Amir

Javid

12.2 Two Dimensional  Arrays

Sometimes data is arranged in rows and columns. Thus two or more subscripts are needed to represent each element in such arrays.

Class	Present	Leave	Absent
7	60	3	2
8	52	1	1

The locations of the data in this table can be described by numbering both rows and tables as given below.

	Col. 1	Col. 2	Col. 3	Col. 4
Row 1	A (1, 1) 7	A (1, 2) 60	A (1, 3) 3	A (1, 4) 2
Row 2	A (2, 1) 8	A (2, 2) 52	A (2, 3) 1	A(2, 4) 1

12.3 Filling and printing Two Dimensional Arrays

One way of filling a two dimensional arrays is by For…Next nested loop.

Program

10 Dim A(2, 4)

20 For Row=1 to 2

30 For Col = 1 to 4

40 Read A (Row, Col)

50 Next Col

60 Row

70 Data 7, 60, 3, 2

80 Data 8, 52, 1, 1

90 For Row=1 to 2

100 For Col = 1 to 4

110 Print A (Row, Col)

120 Next Col

130 Row

140 End