Unary negation (-)

Try it

const x = 4;
const y = -x;

console.log(y);
// Expected output: -4

const a = "4";
const b = -a;

console.log(b);
// Expected output: -4

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

• Addition (+)
• Subtraction (-)
• Division (/)
• Multiplication (*)
• Remainder (%)
• Exponentiation (**)
• Increment (++)
• Decrement (--)
• Unary plus (+)