duddilla's said:
And my other question is what are
exact differences between C++ and Ruby? and Ruby and Java?
There are a lot of differences. Here are some that come to mind right away:
In ruby everthing is an object:
5.class #=> Integer
Integer.class #=> Class
Ruby has convenient introspection methods:
some_object.class # What's some_object's class?
some_object.respond_to?("meth") # Does some_object have the method "meth"
some_object.methods # Which methods does this object have
SomeClass.instance_methods # Which methods do instances of the class have
...
In ruby you can reopen classes:
5.double #=> Error: No such method
class Integer
def double()
self * 2
end
end
5.double #=> 10
Ruby has dynamic typing:
x = 5
x.class #=> Integer
x = "lala"
x.class #=> String
Ruby has blocks and a lot of methods that make good use of them:
[1,2,3,4].map {|x| x+3} #=> [4,5,6,7]
[5,7,11,8].any? {|x| x>10} #=> true
[5,7,11,8].all? {|x| x>10} #=> false
5.times { puts "Hello world" } # Prints "Hello World" five times.
In ruby you can easily define methods dynamically:
class String
(2..10).each do |i|
define_method("print_#{i}_times") do
i.times {puts self}
end
end
end
"hi".print_4_times # Prints "hi" 4 times
And a lot of other things.
HTH,
Sebastian
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