# BASIC/Introduction

 Completion status: this resource has reached a high level of completion.

BASIC, which is an acronym for Beginner's All-purpose Symbolic Instruction Code, high level language that stresses ease of use. It was developed in 1964 by John George Kemeny and Thomas Eugene Kurtz with a goal to create a programming language that anyone could use. Although BASIC is no longer widely used as it once was, it is still a popular programming language used on personal computers and microcontrollers.

BASIC source code has .bas extension, e.g main.bas

## Hello, World !

hello.bas

```' This program displays "Hello world!"
'
' References:
'     http://www6.uniovi.es/qbasic/qtutor1.html

PRINT "Hello world!"
```

## Variables

Example 1: Convert a Fahrenheit temperature to Celsius

```DIM Fahrenheit
DIM Celsius

PRINT "Enter Fahrenheit temperature:"
INPUT Fahrenheit

Celsius = (Fahrenheit - 32) * 5 / 9

PRINT STR\$(Fahrenheit) + "° Fahrenheit is " + STR\$(Celsius) + "° Celsius"
```

Example 2: Addition and subtraction of (random) integral numbers

```' Program to create examples for addition and subtraction of integral numbers for output on printers

#lang "fblite"
dim as integer max,a,b,n,i

print
input "Maximum absolute value of the numbers [default: 100]: ";max
if max<2 then
max=100
end if
print
input "How many examples [default: 25] ";n
if n<=0 then
n=25
end if
Lprint         ' output on the printer
Lprint
Lprint
Lprint "        ";n;" arithmetical exercises with integral numbers from ";-max;" to";max
Lprint
Lprint

randomize      'initialize the rnd random-number generator
for i=1 to n
a=int(rnd*(2*max+1))-max
b=int(rnd*(2*max+1))-max
Lprint using "       ###)   ";i;
Lprint a;
if b<=0 then
Lprint " -";abs(b)
else
Lprint " +";b
end if
Lprint
Lprint
next i
Lprint Chr(12)   ' for output on computer screen use the command "sleep"
```