# Subtraction Operator (-) (JavaScript)

Subtracts the value of one expression from another or provides unary negation of a single expression.

result = number1 - number2

-number

In Syntax 1, the **-** operator is the arithmetic subtraction operator used to find the difference between two numbers. In Syntax 2, the **-** operator is used as the unary negation operator to indicate the negative value of an expression.

For Syntax 2, as for all unary operators, expressions are evaluated as follows:

If applied to undefined or null expressions, a run-time error is raised.

Objects are converted to strings.

Strings are converted to numbers if possible. If not, a run-time error is raised.

Boolean values are treated as numbers (0 if false, 1 if true).

The operator is applied to the resulting number. In Syntax 2, if the resulting number is nonzero, *result* is equal to the resulting number with its sign reversed. If the resulting number is zero, *result* is zero.

Supported in the following document modes: Quirks, Internet Explorer 6 standards, Internet Explorer 7 standards, Internet Explorer 8 standards, Internet Explorer 9 standards. See Version Information.