Addition Operator ()
Adds the value of one numeric expression to another or concatenates two strings.
expression1 + expression2
Arguments
expression1
Any expression.expression2
Any expression.
Remarks
The type of the expressions determines the behavior of the + operator.
If |
Then |
Result Type |
|---|---|---|
Both expressions are char |
Concatenate |
String |
Both expressions are numeric |
Add |
numeric |
Both expressions are strings |
Concatenate |
String |
One expression is char and the other is numeric |
Add |
char |
One expression is char and the other is a string |
Concatenate |
String |
One expression is numeric and the other is a string |
Concatenate |
String |
For concatenation, numbers are coerced into a string representation of the numeric value, and chars are considered to be strings of length 1. For addition of a char and a number, the char is coerced into a numeric value, and the two numbers are added.
Note
In scenarios where type annotation is not used, numeric data may be stored as a strings. Use explicit type conversion or type annotate variables to ensure that the addition operator does not treat numbers as strings, or vice versa.
Example
The following example illustrates how the addition operator processes expressions of different types.
var str : String = "42";
var n : double = 20;
var c : char = "A"; // the numeric value of "A" is 65
var result;
result = str + str; // result is the string "4242"
result = n + n; // result is the number 40
result = c + c; // result is the string "AA"
result = c + n; // result is the char "U"
result = c + str; // result is the string "A42"
result = n + str; // result is the string "2042"
// Use explicit type coversion to use numbers as strings, or vice versa.
result = int(str) + int(str); // result is the number 84
result = String(n) + String(n); // result is the string "2020"
result = c + int(str); // result is the char "k"