Specifications

BASIC Stamp II

Parallax, Inc. • BASIC Stamp Programming Manual 1.8 • Page 273

Table I-2. Effects of the Logical Operators Used by

If...Then

Condition A NOT A

false true

true false

Condition A Condition B A AND B

false false false

false true false

true false false

true true true

Condition A Condition B A OR B

false false false

false true true

true false true

true true true

Condition A Condition B A XOR B

false false false

false true true

true false true

true true false

Unlike some versions of the If...Then instruction, PBASIC’s If...Then

can only go to a label as the result of a decision. It cannot conditionally

perform some instruction, as in “IF x < 20 THEN y = y + 1.” The PBASIC

version requires you to invert the logic using NOT and skip over the

conditional instruction unless the condition is met:

IF NOT x < 20 THEN noInc ' Don't increment y unless x < 20.

y = y + 1 ' Increment y if x < 20.

noInc: ... ' Program continues.

You can also code a conditional Gosub, as in “IF x = 100 THEN GOSUB

centennial.” In PBASIC:

IF NOT x = 100 then noCent

gosub centennial ' IF x = 100 THEN gosub centennial.

noCent: ... ' Program continues.