JS Built-ins
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NumberNaNbeginner

Number.NaN — NaN is not equal to itself

📖 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.

Number.NaN

Number.NaN is the same as the global NaN. One unique property: NaN !== NaN.

Number.NaN === Number.NaN  // → false!
💡 Hints (1)
  • • `NaN` is the only JavaScript value not equal to itself — use `Number.isNaN()` to check for it.