# + (addition)

#### Availability

Flash Player 4; Flash Player 5. In Flash 5, `+` is either a numeric operator or string concatenator depending on the data type of the parameter. In Flash 4, `+` is only a numeric operator. Flash 4 files brought into the Flash 5 or later authoring environment undergo a conversion process to maintain data type integrity. The following example illustrates the conversion of a Flash 4 file containing a numeric quality comparison:

Flash 4 file:

    x + y

Converted Flash 5 file:

    Number(x) + Number(y)

#### Usage

    expression1 + expression2

#### Parameters

`expression1,expression2` A number or string.

#### Returns

None.

#### Description

Operator; adds numeric expressions or concatenates (combines) strings. If one expression is a string, all other expressions are converted to strings and concatenated.

If both expressions are integers, the sum is an integer; if either or both expressions are floating-point numbers, the sum is a floating-point number.

#### Example

The following example concatenates two strings and displays the result in the Output window.

    name = "Cola";
    instrument = "Drums";
    trace (name + " plays " + instrument);

#### Example

Variables associated with dynamic and input text fields have the data type String. In the following example, the variable `deposit` is an input text field on the Stage. After a user enters a deposit amount, the script attempts to add `deposit` to `oldBalance`. However, because `deposit` is a String data type, the script concatenates (combines to form one string) the variable values rather than summing them.

    oldBalance = 1345.23;
    currentBalance = deposit + oldBalance;
    trace (currentBalance);

For example, if a user enters 475 in the deposit text field, the `trace` action sends the value 4751345.23 to the Output window.

To correct this, use the `Number` function to convert the string to a number, as in the following:

    currentBalance = Number(deposit) + oldBalance;

#### Example

This statement adds the integers 2 and 3 and displays the resulting integer, 5, in the Output window:

    trace (2 + 3);

This statement adds the floating-point numbers 2.5 and 3.25 and displays the result, `5.75`, a floating-point number, in the Output window:

    trace (2.5 + 3.25);

#### See also

`_accProps`