RadExpressionEditor allows you to use different constants for defining the expression you want. There are several types supported by the control:
Numeric constants - you may define just a simple numeric expression like:
In case of Double constant, you could use the exponential value: 0.0E+2. As a Decimal constant you could use '0.0'.
String constants - they need to be surrounded by double quotation marks:
DateTime constants - they need to be surrounded by hashes:
Boolean constants - they can be defined as "True" / "False" values. In the same way you may define null constant - "null".