JavaScript tutorial:
- Operator

The (-) operator is used to find the difference between two numbers or to indicate the negative value of a numeric expression.

Syntax 1

result = number1 - number2

Syntax 2

-number

The - operator syntax has these parts:

Part	Description
result	Any numeric variable.
number	Any numeric expression.
number1	Any numeric expression.
number2	Any numeric expression.

Example

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 information on when a run-time error is generated by Syntax 1, see the Operator Behavior table.

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.

See also: -= Operator, Operator Behavior, Operator Precedence, Operator Summary