UNB/ CS/ David Bremner/ teaching/ cs2613/ books/ mdn/ Reference/ Operators/ Unary negation (-)

The unary negation (-) operator precedes its operand and negates it.

Syntax

-x

Description

The - operator is overloaded for two types of operands: number and BigInt. It first coerces the operand to a numeric value and tests the type of it. It performs BigInt negation if the operand becomes a BigInt; otherwise, it performs number negation.

Examples

Negating numbers

const x = 3;
const y = -x;
// y is -3; x is 3

Negating non-numbers

The unary negation operator can convert a non-number into a number.

const x = "4";
const y = -x;

// y is -4

BigInts can be negated using the unary negation operator.

const x = 4n;
const y = -x;

// y is -4n

Specifications

Browser compatibility

See also