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I have seen a lot usage of double colons in Rails before class names.
For example:
require ::File.expand_path('../config/environment', __FILE__) I know what Module::Class::Constant means, but ::Class ?
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The :: is a unary operator that allows: constants, instance methods and class methods defined within a class or module, to be accessed from anywhere outside the class or module.
The :: is a unary operator and is used to access (anywhere outside the class or module) constants, instance methods and class methods defined within a class or module. Note: In Ruby, classes and methods may be considered constants too.
What is symbol. Ruby symbols are created by placing a colon (:) before a word. You can think of it as an immutable string. A symbol is an instance of Symbol class, and for any given name of symbol there is only one Symbol object.
Use the `!!` (Double-bang) Operator for Boolean Values In most programming languages, including Ruby, ! will return the opposite of the boolean value of the operand. So when you chain two exclamation marks together, it converts the value to a boolean.
It means that you're referring to the constant File from the toplevel namespace. This makes sense in situations like this:
class MyClass #1 end module MyNameSpace class MyClass #2 end def foo # Creates an instance of MyClass #1 ::MyClass.new # If I left out the ::, it would refer to # MyNameSpace::MyClass instead. end end If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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