JavaScript - `parseInt` vs `Number` comparision

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parseInt(string, radix);

var a = new Number('123'); // a === 123 is false
var b = Number('123'); // b === 123 is true
  • parseInt takes 2 arguments

Number:

  • returns NaN for string 123sdfdsf
  • returns NaN for undefined, NaN and {}
  • returns 0 for false, null, "", " "
  • returns 1 for true

parseInt:

  • returns 123 for string 123sdfdsf
  • returns NaN for all false, null, "", " ", true, {}, undefined and NaN
  • parseInt preferable for inputs where user can leave some additional characters