Atari 800

66 User's Handbook to the Atari 400/ 800 Computers
100 PRINT "ENTER YOUR AGE";
200 INPUT AGE
In the preceding example, the prompt, "ENTER YOUR AGE", will
appear on the same line as the INPUT prompt.
Loops
Suppose that you ne eded to compute the squares of the integers
from 1 to 20. One way of doing this is by calcul ating the square
for each individual int eger as s hown below.
100 A = 1 "2
200 PRINT A
300 B = 2 "2
400 PRINT B
500 C = 3 "2
600 PRINT C
However , this m ethod is very cumbersome. This problem
could be solved mu ch more effic i ent ly through the u se of a
FOR, NEXT loop as show n below.
100 FOR A = 1 TO 20
200 X = A "2
300 PRINT X
400 NEXT A
500 END
The sequence of statements from 100 to 400 is known as a loop.
When the computer encounters the FOR statement in lin e 100,
the variable A is set to 1. X is then calc ul ated and displayed in
lines 200 and 30 0.
The NEXT statement in lin e 400 will request the next value for A.
Execution
returns to line 100 where the value of A is in creme nt ed
by 1 (to 2) and then compa red to the value appearing afte r TO.
Since
the value of A is l ess than that value, the l oop will be
executed again with the va lue of A set at 2.