Search code examples
javascriptnumberstransformationnumerical

Numerical transformation in javascript and math operation

Here is the code: 

alert(typeof(+"13t"));
alert(1 + (+"13t"));

Why in the first line the output is "number" And in the second line the output is "NaN"??

Solution

  • The value NaN is a number. Even though NaN means "not a number", it's still got the data type "number".

    The string "13t" when coerced to a number value yields NaN, unsurprisingly. Adding 1 to NaN also yields NaN.