Decrement operator

Two minus signs lowering a value by one.

Everyday & digitalStandard profile

Meaning

Two minus signs subtract one from a variable in place, the counterpart of the increment operator and following the same prefix and postfix rule.

Officially standardisedVerified fact
ECMAScript defines both the prefix and postfix forms: each subtracts one from the operand, differing in the value the expression produces.
Contexts: Software

Two short horizontal strokes set side by side at mid height, level with one another and evenly spaced.

IdentityHigh confidence: High confidence because the identity is defined by a current official standard, but only a single source has been found so far.
Historical originLow confidence: Low confidence because the historical origin is documented in encyclopedic references, but only a single source has been found so far, but early or supporting evidence is limited, but the regional or cultural match to this specific claim is not precise.
Current useHigh confidence: High confidence because the current use is defined by a current official standard, but only a single source has been found so far.
Visual matchModerate confidence: Moderate confidence because the visual match is documented in encyclopedic references, but only a single source has been found so far.

ECMA-262, ECMAScript Language Specification
Ecma International · retrieved 2026-08-01
Authoritative for JavaScript's own syntax and only for that. A construct spelled the same way in another language may behave differently, and records say which language they are describing.

Last reviewed 2026-08-01