Introduction

An operator is a symbol that represents a specific action. For example, a plus sign (+) is an operator that represents addition. Operators are used within ISML Expressions and allow you to manipulate numerical and string values stored as variables or constants. In case one or more operators are not of the required types as described below, a runtime exception will occur.

References

Reference - ISML Expressions

Arithmetic Operators

The standard arithmetic operators are addition, subtraction, multiplication and division. Arithmetic operators take numerical values (either literals or variables) as their operands and return a single numerical value. Arithmetic operators work the same in ISML expressions as they do in other common programming languages.

Note

Division by zero is not defined and will result in a runtime exception.

The examples in the table below assume that var has been assigned the value 2.

Operator	Description	Examples Returning Value 5
+	Addition	var + 3
-	Subtraction	7 - var
*	Multiplication	2,5 * var
/	Division	10 / var

Arithmetic Comparison Operators

These operators compare numerical operands and return a Boolean value based on whether or not the comparison is true. The table below shows valid operators.
Operands for arithmetic comparison operators must be classes of type number and their subclasses, e.g., money. The result is of type Boolean.

The examples in the table below assume that var has been assigned the value 2.

Operator	Description	Examples Returning True
==	Equal: Returns true if the operands are equal.	var == 2
!=	Not Equal: Returns true if the operands are not equal.	var != 0
>=	Greater Than or Equal To: Returns true if the left operand is greater than or equal to the right operand.	3 >= var; 2 >= var
<=	Less Than or Equal To: Returns true if the left operand is less than or equal to the right operand.	var <= 5; var <= 2
>	Greater Than: Returns true if the left operand is greater than the right operand.	12 > var
<	Less Than: Returns true if the left operand is less than the right operand.	1 < var

Logical Operators

Logical operators are used to build complex expressions that evaluate to true or false.

Type of operands: Boolean; result type: Boolean.

For the examples in the table below assume that variable var_true has been assigned the value of true and var_false the value of false.

Operator	Description	Examples Returning True
AND	Returns `true` if both operators are true.	var_true AND var_true
OR	Returns `true` if at least one of the two operators is true.	var_true OR var_false var_false OR var_true
NOT	Returns `true` if its single operator is false, otherwise it returns `false`	NOT var_false

String Concatenation Operator

Use the Concatenation Operator to concatenate two strings and return another string that is their union. If an operand is not a string, it is automatically converted into a string.

Type of operands: String, result type: String.

Operator	Description
.	Period: Returns the concatenation of two string operands.

String Comparison Operators

These operators compare string operands and return a logical value based on the comparison. The value is equal only if both combined strings contain exactly the same characters. In the case that an operand is not of type string, it is automatically converted into a string.

Type of operands: String, result type: Boolean.

Operator	Description
EQ	Returns `true` if the two string operands are equal, otherwise `false`.
NE	Returns `true` if the two string operands are not equal, otherwise `false`.

Reference - ISML Reference

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