Note: information on this page refers to Ceylon 1.1, not to the current release.

+ (sum) operator

The left-associative, binary infix + operator is used to sum two operands.


Integer three = 1 + 2;
String concatenated = "foo" + "bar";



The + operator is defined as follows:;

See the language specification for more details.


The + operator is polymorphic. The meaning of + depends on the Summable interface.


The result type of the + operator is the same as the type of its right hand operand.

Meaning of + for built-in types

For the built-in numeric types Integer and Float, + performs normal mathematical addition, subject to the limitations of the relevant type.

For String, + performs concatenation.

See also