If I type a number in the browser console the result is:
1000000000000000000000 --> 1e+21
0.00000000003453 --> 3.453e-11
I want to determine the number after e. In this example, the number is 21 or -11
Thanks!
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Nick Parsons
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Matt Nguyen
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https://stackoverflow.com/questions/9383593/extracting-the-exponent-and-mantissa-of-a-javascript-number Maybe this can help you. – Marty Oct 04 '19 at 04:29
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What should smaller numbers give you? For example, should 123 give `123` or `2`? – Nick Parsons Oct 04 '19 at 04:34
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Thanks @Marty, I see the someone use `toExponential()` in this thread. And this is what I want to solve – Matt Nguyen Oct 04 '19 at 04:46
1 Answers
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You can convert the number to a string using .toExponential() and then split based on e and get the last element (which would be your number) like so:
const getExp = n =>
+(n.toExponential().split('e').pop())
console.log(getExp(1000000000000000000000)) // 21
console.log(getExp(0.00000000003453)); // -11
console.log(getExp(0.000324)); // -4
Nick Parsons
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It works for really long number like that. If the number is 0.000324 it doesn't work. Maybe javascript has some way to convert it. btw, it works for my case. Thanks, you're clever! – Matt Nguyen Oct 04 '19 at 04:37
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@MattNguyen you could use `toExponential()` to make it work for smaller numbers (I've edited my answer now) – Nick Parsons Oct 04 '19 at 04:40
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