Adds the value of one numeric expression to another, or concatenates two strings.
Syntax
result = expression1 + expression2
Parameters
result
Any variable.
expression1
Any expression.
expression2
Any expression.
Remarks
The types of the two expressions determine the behavior of the + operator.
| 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 |
Requirements
Supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards, Internet Explorer 10 standards, Internet Explorer 11 standards. Also supported in Store apps (Windows 8 and Windows Phone 8.1). See Version Information.
See Also
Addition Assignment Operator (+=)
Operator Precedence
Operator Summary (JavaScript)