TIL, 2017-05-09
group_by
–we can do things like this:names.group_by { |name| name[0] }
data.group_by { |number| number /20 }
- Ruby Struct, you can get elements by index as well by name:
- Structs don’t have native keyword argument support.
Person = Struct.new(:name, :age)
p = Person.new("fred", 26)
p[0]
- The error that Ruby raises when it can’t find a method is
NoMethodError
. cp -i
for interactive mode,cp -r
for copying recursively.mv -i
for interactive mode.rm -r
for recursive directory removal.chmod 777 myfile
. Number explanation: