+ Operator
Description
Used to sum two numbers or perform string concatenation.
Syntax
result = expression1 + expression2The + operator syntax has these parts:
Part Description result Any variable. expression1 Any expression. expression2 Any expression. Remarks
The underlying subtype of the expressions determines the behavior of the + operator in the following way:
If Then Both expressions are numeric or boolean Add. Both expressions are strings Concatenate. One expression is numeric and the other is a string Concatenate. As for all arithmetic operators, JScript will generate runtime errors for every case in the table below where an E is indicated:
obj as ns num bool undef null obj N E N N N E E as E E E E E E E ns N E N N N E E num N E N N N E E bool N E N N N E E undef E E E E E E E null E E E E E E E obj = Object, as = Alphanumeric String, ns = Numeric String, num = Number, bool = Boolean, undef = Undefined, null = Null value.