Syntax - Feature Comparison (Basic Syntax <-> Crystal Syntax)

Writing formulas can either be done in Crystal or in Basic syntax.

Basic Syntax

The syntax rules of the basic syntax are very similar to those of Microsoft's Visual Basic and other forms of Basic.

Crystal Syntax

The syntax rules of the crystal syntax are similar to the formula syntax of Crystal Reports.

Feature Basic Syntax Crystal Syntax
Case-sensitive? No No
Variable declaration 
dim a as number
dim b as string
 
numbervar a;
stringvar b;
Variable assignment 
a = 10
 
a := 10;
Variable scope Local: 
dim a
or 
local a
Shared: 
shared a
Global: 
global a
 Local: 
local numbervar a;
Shared: 
shared numbervar a;
Global: 
global numbervar a;
or
   
numbervar a;
(Default)
Comparison operators 
10 < pi()*3
10 = a
Rem a = 10 would be assignment
 
10 < pi() * 3;
a = 10; 	// or 10 = a
End of statement(s) Line Break or Colon Semi-colon
Result of formula Assign return value to variable 
formula
 Result of last line
Comment 
' comment
Rem comment
 
// comment
If then else statement 
global a as number
if a = 10 then
	a = 20
	formula = "a was 10"
elseif a = 20 then
	a = 30
	formula = "a was 20"
else
	a = 0
	formula = "a was not 10 or 20"
end if
 
numbervar a;
if a = 10 then (
	a := 20;
	"a was 10";
) else if a = 20 then (
	a := 30;
	"a was 20";
) else (
	a := 0;
	"a was not 10 or 20";
);
"For" loop 
formula = ""
dim i
for i = 1 to 10 step 2
	formula = formula + "ab"
next i
' Returns: "ababababab"
 
stringvar result := "";
numbervar i;
for i := 1 to 10 step 2 Do (
	result := result + "ab";
);
result;
// Returns: "ababababab"
"While" loop 
formula = ""
dim i as number
i = 1
do while i <= 10
	i = i + 2
	formula = formula + "ab"
loop

' Returns: "ababababab"
 
stringvar result := "";
numbervar i := 0;
while i <= 10 Do (
	i := i + 2;
	result := result + "ab";
);
result;
// Returns: "ababababab"
principles Basic accepts only statements that "do something". Therefore a single number is not a statement. It may be an expression within an if-condition. But in case you assign that number to a variable it becomes a correct statement because it does an assignment. In Crystal Syntax everything has a return value - at least "null". As a result everything is a statement and the last evaluated statement delivers the returned value.

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