SC's biggest number?

Questions
1

Hello world :wave:

If I try to divide 14 billion by two I get this result:

14000000000/2;
557549056.0

Two problems: the answer is wrong; it turns the integer into a float.

Also this function continuously dividing by 10 (which while Iā€™m at it, feels wrong - I wonder is there a simpler way to achieve the same idea?) gives another strange result of 1115098112:

10.collect({|i| 14000000000.div(10.pow(i))});
[ 1115098112, 111509811, 11150981, 1115098, 111509, 11150, 1115, 111, 11, 1 ]

I found this is the integer help file:

Blockquote
NOTE: A 32 bit signed integer can represent values in the range -2147483648 to 2147483647. Adding up further returns in a wrapped result, so that and 2147483647+1= -2147483648. For a larger range, one can use Float, which is 64 bit and supports many (but not all) numerical methods that int does.
Blockquote

So I took the advice and turned the 14 billion into a float:

10.collect({|i| 14000000000.0.div(10.pow(i))});
[ 1115098112, 1400000000, 140000000, 14000000, 1400000, 140000, 14000, 1400, 140, 14 ]

Still a strange result, if almost what I expected. The number 1115098112 appears again.

I would be very grateful if anyone could enlighten me to what exactly is happening with these big numbers!

Many thanks,

Dom

2

Hello,

According to the .div help document, it is an integer division.
Please compare the followings:

14000000000.0 / 10.pow(0)    // returns 14000000000.0
14000000000.0 / (10**0)      // returns 14000000000.0 
14000000000.0.div(10.pow(0)) // returns 1115098112

My supposition is the method .div treats the number 14000000000.0 as an integer. Thus, sclang thinks the value of 14000000000.0 is 1115098112.
Then,

1115098112.div(10.pow(0))

is 1115098112.
I hope my understanding is correct and helps you.

3

Hi prko,

Well done for working this out, and thank you. I thought it was something deeper in the language.

Much appreciated! :slight_smile:

1 Like