Each statement in a formula is evaluated in a sequential order if the formula doesn't contain any statement to control the flow of evaluation. A statement in the first line is evaluated before a statement in the second line. Statements for controlling the flow of evaluation are called 'control structures' and can be summarized into two groups - conditional statements and loop statements. The syntax of such statements differs in basic and crystal syntax.

Using conditional statements means the evaluation of an statement depends on the evaluation of a guard expression. If the guard expression evaluates to 'true' then the statement will be evaluated. If a guard expression evaluates to 'false' then the guard of another statement (if defined) will be checked or (if no alternative was defined) nothing will be evaluated.

Using loop statements means the evaluation of a statement for more than one times. A guard expression controls the amount of recalculations of the loop statement.

With the operator "Option Loop" it is possible to change the maximum number (default: 100000) of loop cycles for all loops in a formula.

• If statement
• Select statement
• For Loop
• Exit For
• While Loops
• Exit While
• Option loop

• If statement
• Select statement
• For/Next loop
• Exit For
• Do loops
• Exit Do
• While loop
• Option loop