Maximus Maximus - 6 months ago 11
Javascript Question

Is there any way to see a number in it's 64 bit float IEEE754 representation

Javascript stores all numbers as double-precision 64-bit format IEEE 754 values according to the spec:


The Number type has exactly 18437736874454810627 (that is, 264−253+3)
values, representing the double-precision 64-bit format IEEE 754
values as specified in the IEEE Standard for Binary Floating-Point
Arithmetic


Is there any way to see the number in this form in Javascript?

Answer

You can use typed arrays to examine the raw bytes of a number. Create a Float64Array with one element, and then create a Uint8Array with the same buffer. You can then set the first element of the float array to your number, and examine the bytes via the Uint8Array. You'll have to do some shifting and combining for the various pieces of the number of course, but it's not hard.

There are no built-in facilities to do things like extract the exponent.

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