Hacker News 上的今日热帖，求 9999999999999999.0 – 9999999999999998.0，哪种编程语言的浮点计算能给出正确答案？
| Ruby: |
irb(main):001:0> 9999999999999999.0 - 9999999999999998.0
2.0 |
| Java: |
public class Foo{public static void main(String args[]){System.out.println(9999999999999999.0-9999999999999998.0);}}
2.0 |
| Python: |
>>> 9999999999999999.0 - 9999999999999998.0
2.0 |
| Rebol: |
>> 9999999999999999.0 - 9999999999999998.0
== 2.0 |
| Haskell: |
Prelude> 9999999999999999.0 - 9999999999999998.0
2.0 |
| TCL: |
% expr "9999999999999999.0-9999999999999998.0"
0.0 |
| Emacs Lisp: |
ELISP> (- 9999999999999999.0 9999999999999998.0)
2.0 |
| Common–Lisp: |
[1]> (- 9999999999999999.0 9999999999999998.0)
0.0 |
| Maxima: |
(%i1) 9999999999999999.0-9999999999999998.0;
(%o1) 2.0 |
| Google: |
0 |
| K/Q: |
q)9999999999999999.0-9999999999999998.0
2f |
| R: |
> 9999999999999999.0-9999999999999998.0
[1] 2 |
| Erlang: |
1> 9999999999999999.0-9999999999999998.0 .
2.0 |
| C: |
main(){printf("%lf\n",(double)9999999999999999.0-9999999999999998.0);}
2.000000 |
| AWK: |
$ awk 'END{print 9999999999999999.0-9999999999999998.0}'</dev/null
2 |
| GoLang: |
var a = 9999999999999999.0; var b = 9999999999999998.0; fmt.Printf("%f\n", a-b)
2.000000 |
| Perl: |
$ perl -e 'print 9999999999999999.0-9999999999999998.0;print "\n";'
2.0 |
| Perl6: |
$ perl6 -e 'print 9999999999999999.0-9999999999999998.0;print "\n";'
1 |
| Wolfram: |
1 |
| soup: |
9999999999999999.0-9999999999999998.0
1 |
最后看看 ChatGPT 的回答：
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来源：https://geocar.sdf1.org/numbers.html
