Commodore PET - Then

Format:
1F condition
{
statement
THEN
statement:statement. ..
Conditionally execute statement.
Conditionally execute statements.
1F condition{THEN} line
GOTO
Conditionally branch.
line
statement
where:
condition
is a relational term (with "< >0" implied) or a rela-
tional expression.
is any PET BASIC statement valid for the current
mode (program or immediate) that may be condi-
tionally executed.
is a numeric constant specifying the line to be
branched to.
If the specified condition is true, then the statement or statements following
the THEN are executed. If the specified condition is false, control passes to the
next sequential statement on the next line number without executing the state-
ment or statements following the THEN. A conditional branch may be written in
the form of a line number to
be branched to placed after the word THEN or after
the word GOTO. The compound form THEN GOTO is also acceptable.
IF A = 1 THEN 50 }
IF A = 1 GOTO 50 equivalent
IF A = 1 THEN GOTO 50
If
an unconditional branch is in a multiple-statement IF ... THEN, the branch
must be the last statement on the line and must be in the traditional "GOTO line"
form. If it
is not the last statement on the line, the statements following the un-
conditional branch are never executed. The form "THEN line"
is an alternative to
"GOTO line" and cannot be used with multiple statements intervening between
the
"THEN" and the 'ïine."
IF ... THEN may be given in immediate or program mode.
ln an immediate mode IF ... THEN, the following statements are illegal or
non-functional: DATA,
GET, GET#, INPUT, INPUT#, REM, RETURN, END, STOP,
WAIT. If a line number is specified, or any statement containing a line number,
there must
be a corresponding statement with that line number in the current
stored program if the branch may
be taken.
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