QuestenaÜben und erkennen, was als Nächstes dran ist
Frage 119

Which call returns true under the non-coercing rules of Number.isNaN?

  1. Number.isNaN("hello")
  2. Number.isNaN(undefined)
  3. Number.isNaN(NaN)Richtige Antwort
  4. Number.isNaN("NaN")

Erklärung

Number.isNaN returns true only when its argument is already the Number value NaN, so Number.isNaN(NaN) succeeds. It does not coerce the string hello or undefined before testing, unlike the coercing behavior associated with the global isNaN function.

Mit diesem Test weitermachen

Übung starten