Allows for the conditional execution of some statements. It takes the general form:
IF expression THEN|ELSE statement
- The expression evaluates to a value of Boolean TRUE or FALSE.
- If the expression is TRUE, the statements defined by the THEN clause will execute (if present).
- If the expression is FALSE, the statements defined by the ELSE clause, if any will execute.
- The THEN and ELSE clauses may take two different forms being single and multiple line statements.
The simplest form of either clause is of the form:
IF A THEN CRT A
IF A ELSE CRT A
However, the END keyword may be used to expand the clauses to enclose multiple lines of code as so:
IF A THEN A = A*6 CRT A END ELSE A = 76 CRT A END
It is possible to combine the single and multi-line versions of either clause to make complex combinations of the command. For reasons of readability it is suggested that where both clauses are present for an IF statement that the same form of each clause is coded.
IF statements can be nested within either clause to any number of levels.
An example of use is as:
0001 CRT "Are you sure (Y/N) ": 0002 INPUT Answer,1 0003 IF OCONV (Answer, "MCU")= "Y" THEN 0004 *Call delete subroutine here 0005 CRT "Files have been deleted" 0006 END ELSE 0007 CRT "File delete was ignored" 0008 END
Go back to jBASE BASIC.