Rails
Ruby 3.0
6.1
6.0
5.2
5.1
5.0
4.2
2.5.0
2.6.0
2.7.0
constant Math::E
E -> Float
[
permalink
][
rdoc
][
edit
]
自然対数の底
例
p
Math
::
E
# => 2.718281828