In 7.2.4 we have seen the assignment statement
LET output = (i>5)
An assignment is an expression with a value and assignments associate from right to left. The condition test (i>5) returns the value 1 or 0, depending whether the test results true or false. But CSI(C&F) offers the possibility, to formulate more transparent and complex decision structures. Now we modify the referenced example to bring it to a more readable form:
/* the use of IF - THEN - ELSE */
FOR i = 1 TO 10 STEP 1
IF (i>5) THEN
PRINT i
PRINT " is greater than 5"
PRINT CR
ELSE
PRINT i
PRINT " is lower than or equal 5"
PRINT CR
ENDIF
NEXT i
This example shows a THEN and an ELSE statement block, which specifies the alternative actions if the condition part of an IF statement is true or false. The general form is
IF <condition> THEN
<statement block 1>
ELSE
<statement block 2>
ENDIF
One and only one of the two statement blocks associated with an IF-THEN-ELSE statement is performed. If the condition is true, <statement block 1> is executed; if not, <statement block 2> is executed. Like anywhere, a statement block can be a single statement or several statements.