15 Significant digit limit

[Xotic750]

I was wondering why the number type input is limited to 15 significant digits when Javascript can represent an integer to 16?

Ie. -9007199254740991 to 9007199254740991

    // Disallow numbers with over 15 significant digits if number type.
    if ( isNum && b > 15 && n.slice(i).length > 15 && +n.slice(i) > 9007199254740991) {

        // 'new BigNumber() number type has more than 15 significant digits: {n}'
        ifExceptionsThrow( orig, 0 )
    }

I'm not suggesting this is the fix/enhancement as I'm sure there is more to it than that.

[MikeMcl]

Yes, I discussed this in #11.

Basically, with double precision values there is no guarantee that decimal numbers with sixteen significant digits or more will be represented precisely. For example,

console.log( 823456789123456.3 );    // 823456789123456.2

In any case, the 15 s.d. limit can be turned off with

BigNumber.config({ ERRORS: false });

[Xotic750]

Thanks for that, don't know how I missed it.

I don't particularly want to turn off the error, it will come in very useful, but what I had hoped is that if I enter the value as a string ("9007199254740991") rather than a number type (9007199254740991) then I wouldn't experience the error. That is what you also seem to suggest in the other thread, but it does not work for me, perhaps I am missing something else?

[Xotic750]

Ok, it must be something that I am doing locally in my app, as it works in a jsfiddle without the rest of my code. Thanks once again.