BASIC stands for Beginner’s All-purposed Symbolic Instruction Code. It was developed in 1960 by John Kemeny and Thomas Kurtz to teach students at Dartmouth College. It has undergone series of historical development, which has resulted in several forms of the language.

BASIC is now in form of VB.NET (Visual Basic.Net). The majority of BASIC languages use program translators called interpreters to allow the computer understand and obey the BASIC statements in the computer program. Examples of such interpreters are:

1. BASICA

2. GwBASIC

3. Turbo BASIC

4. Quick BASIC

1. Alphabetic Characters – A to Z

2. Numeric Character – 0 to 9

3. Special Characters – 0 + % ^ # = ( ) etc.

BASIC symbols used to perform arithmetic operations are:

Operation BASIC Symbol

Addition +

Subtraction –

Multiplication *

Division /

Exponentiation ^

Every arithmetic expression must appear on a single line. There is no superscript in BASIC as we find in algebra.

Key Statement of BASIC

Assignment Statement (LET, INPUT and READ-DATA)

1. LET Statement

The let statement is used to assign a numeric or string value to a variable. The assignment statement must consist a variable, an equal to sign and an expression.

Example

LET X = 12

LET B$ = “Deborah”

LET AREA = L*B

2. INPUT Statement

The INPUT statement is uses to enter data into the computer during program execution.

Example

INPUT A, B, C

INPUT N$, M$, Factor

3. READ-DATA statement

READ and Data are two statement concerned with each other which are used to put data in a line of the program and to read the data when it is needed.

Example

READ A, B, C

DATA 5, 6, 7

LET SUM = A+B+C

PRINT SUM

END

4. REM (Remark) Statement

The REM statement is used to insert comments or remarks into a BASIC program. The use of remark statements improves the readability of the program. It has no effect on the program execution.

REM program to add six numbers

5. PRINT statement

This statement is used to transmit data from the computer memory to the output device.

Examples

PRINT A, B, C

PRINT “I Like Writing Program”

Program Terminator (END and STOP)

6. STOP and END statement

The STOP statement is used to terminate the execution of a program at any point in the program. The END statement indicates the actual end of a program. The STOP statement may appear many times and anywhere, whereas an END statement can only appear at the end of a program and only once.

Example

REM END statement

PRINT “Good morning”

END

7. GO TO statement

This statement transfers program control from the line number that contains the statement to the specific number after GOTO statement.

Example

REM GO TO statement

GOTO 40

PRINT “Good morning”

END

In the case above the program’s control is transferred from line 20 to line 40. This means that the program would end when the execution gets to line 20.

Example 1: Program to find the average of six numbers

10 REM Programs to find the average of six numbers

20 REM Numbers given

30 INPUT “Type in the first number”;A

40 INPUT “Type in the Second number”; B

50 INPUT “Type in the third number”; C

60 INPUT “Type in the forth number”; D

70 INPUT “Type in the fifth number”; E

80 INPUT “Type in the sixth number”; F

40 LET SUM = A+B+C+D+E+F

50 LET AVERAGE = SUM/6

60 PRINT AVERAGE

70 END

Example 2 Program to calculate the perimeter and Area of a Rectangle

REM program to calculate the perimeter and Area of a Rectangle

INPUT “Input the length” L

INPUT “Input the breath” B

LET PERIMETER = 2 * (L + B)

LET AREA = L*B

PRINT “the perimeter is” PERIMETER

PRINT “the area is” AREA

END