The + operator
Sun, Apr 23 2006 22:08
Oh, and if you are wondering how to work them out the rules are actually very simple:
- if both operands are numeric, the result is numeric using the wider type (eg: int + double returns a double
- if one of the operands is numeric and the other string, a numeric operation is performed, the string being converted to double, hence the result is a double
- for booleans the conversion is made to a 16 bit signed integer by default
- a weird rule exists for when both operands are dates, the result being the addition if the date strings.
- if both operands are string (or char), then a string concatenation is performed
Most of these rules will probably never both you except the second rule. If one operand is a string and the other a numeric, then the string will be converted to a double (or crash and burn in trying to do so).
So if you have code like:
Dim x As Int32 = 4
Dim y as String = "2"
Dim result As String = x + y
That code will (a) only compile with strict off semantics, and (b) return "6".
If you wanted 42, then use the concatenation operator, &.
Dim result As String = x & y
will return 42 regardless of strict on or off semantics.