Caché Basic Reference
Addition Operator (+)
[Home] [Back] [Next]
InterSystems: The power behind what matters   

Used to sum two numbers.
result = expression1 + expression2
The + operator syntax has these parts:
result Any numeric variable.
expression1 Any expression.
expression2 Any expression.
Although you can also use the + operator to concatenate two character strings, you should use the & operator for concatenation to eliminate ambiguity and provide self-documenting code.
When you use the + operator, you may not be able to determine whether addition or string concatenation will occur.
The underlying subtype of the expressions determines the behavior of the + operator in the following way:
If Then
Both expressions are numeric Add.
Both expressions are strings Concatenate.
One expression is numeric and the other is a string Add.
If both expressions are Empty, result is an Integer subtype. However, if only one expression is Empty, the other expression is returned unchanged as result.
See Also