isFinite(): test for a finite value

isFinite(x) reports whether x is a finite numeric value, excluding positive infinity, negative infinity, and typically non-numeric values.

Validation before arithmetic

Use it before totals, plotting, or serialization. A finite check prevents one exceptional input from contaminating sum(), mean(), and variance().

Related predicates

isNaN() specifically recognizes “not a number”, while isNumeric() checks numeric type. Use isBounded() for bound-oriented validation.

Scope

A finite result does not guarantee a value is an integer, positive, or suitable for every formula. Add the predicate that matches the actual domain.