# Using operators to manipulate values in expressions

An expression is any statement that Flash can evaluate and that returns a value. You can create an expression by combining operators and values, or by calling a function.

Operators are characters that specify how to combine, compare, or modify the values of an expression. The elements that the operator performs on are called operands. For example, in the following statement, the `+` operator adds the value of a numeric literal to the value of the variable `foo`; `foo` and `3` are the operands:

    foo + 3

This section describes general rules about common types of operators, operator precedence, and operator associativity. For detailed information on each operator mentioned here, as well as special operators that don't fall into these categories, see ActionScript Dictionary.