JS Practice — Built-in Objects

Number.NaN — isNaN check

📖 Usage Example

// Represents Not-a-Number
Number.NaN        // → NaN
Number.isNaN(Number.NaN)  // → true
Number.NaN === Number.NaN // → false (NaN is never equal to itself)

Use Number.NaN as a named constant for Not-a-Number; always check for it with Number.isNaN() since NaN !== NaN.

Detecting NaN

Use Number.isNaN() (strict) or isNaN() (with coercion) to detect NaN.

💡 Hints (1)

• `Number.isNaN()` only returns `true` for actual `NaN` values.