Support of scientific notation

[Kukunin]

I believe that bn.js should support scientific notation for big numbers: a number 5e+21 or a string "5e+21" or both.

Current situation:

new BN('500000000000000000000').toString() // works well
new BN('5e+21').toString() // returns 63521 for some reason
new BN(500000000000000000000).toString() // throws Error: Assertion failed
new BN(5e+21).toString() // throws Error: Assertion failed

I don't know the reasons behind the assertion of big numbers, but at least it can support scientific notation as a string

[nblogist]

@Kukunin Having same issue 2 years later, what did you do to solve this?

Thanks!

[nblogist]

For anyone getting the same issue, apparently BN.js throws from 1e+21 and above, I solved it using the following function:

function toPlainString(num) { // BN.js Throws from 1e+21 and above so using this make shift function
					return (''+num).replace(/(-?)(\d*)\.?(\d+)e([+-]\d+)/,
					  function(a,b,c,d,e) {
						return e < 0
						  ? b + '0.' + Array(1-e-c.length).join(0) + c + d
						  : b + c + d + Array(e-d.length+1).join(0);
					  });
				  }

[qalqi]

Need fix for this

[samlaf]

I would also like to be able to do BigNumber.from('1e27').

[nblogist]

@samlaf this did the job for me 2 years back, is it not working now?

#209 (comment)

[june07]

new BN(${Intl.NumberFormat('en-US').format(1e+99).replaceAll(',','')})

<BN: 1d42aea2879f2e44dea5a13ae3465277b06749ce90c777839e74404a7e8000000000000000000000000>

[samlaf]

Nice @june07 , but still think this should be hidden inside the library. Why do I need this ugly code in my user code?