In Typescript, How to check if a string is Numeric

Question

In Typescript, this shows an error saying isNaN accepts only numeric values

isNaN(\'9BX46B6A\')

and this returns false because parseF

Answer 1

The way to convert a string to a number is with Number, not parseFloat.

Number('1234') // 1234
Number('9BX9') // NaN

You can also use the unary plus operator if you like shorthand:

+'1234' // 1234
+'9BX9' // NaN

Be careful when checking against NaN (the operator === and !== don't work as expected with NaN). Use:

 isNaN(+maybeNumber) // returns true if NaN, otherwise false