JS: Number.isFinite

Number.isFinite(number)

Return true if number is a number type, and is not any of NaN, Infinity, -Infinity. Else, false.

console.assert(Number.isFinite(3) === true);
console.assert(Number.isFinite(3.4) === true);

console.assert(Number.isFinite("3") === false);
console.assert(Number.isFinite(Infinity) === false);
console.assert(Number.isFinite(NaN) === false);