Quick answer: ^[\w*]$ will match a string consisting of a single character, where that character is alphanumeric (letters, numbers) an underscore (_) or an asterisk (*). Details: The “\w” means “any word character” which usually means alphanumeric (letters, numbers, regardless of case) plus underscore (_) The “^” “anchors” to the beginning of a string, and … Read more
this refers to your current object. In your case you must have implemented the intent in an inner class ClickEvent, and thats what it points to. Activity.this points to the instance of the Activity you are currently in.
The bytecode of the Outer$Inner class will contain a package-scoped field named this$0 of type Outer. That’s how non-static inner classes are implemented in Java, because at bytecode level there is no concept of an inner class. You should be able to read that field using reflection, if you really want to. I have never … Read more
Yes. Apologies for getting interrupted (I have to actually do some work every so often). The spec doesn’t explicitly say it, but it makes it pretty clear IMO in section 7.6.10.2: An object initializer consists of a sequence of member initializers, enclosed by { and } tokens and separated by commas. (Note the word “sequence” … Read more
The http: is a Label Statement. See here also. The //www.google.com portion is then interpreted as a // comment.
sum.up is not a valid keyword argument name. Keyword arguments must be valid identifiers. You should look in the documentation of the library you are using how this argument really is called – maybe sum_up?
It is the power operator. From the Python 3 docs: The power operator has the same semantics as the built-in pow() function, when called with two arguments: it yields its left argument raised to the power of its right argument. The numeric arguments are first converted to a common type, and the result is of … Read more
a += b is short-hand for a = a + b (though note that the expression a will only be evaluated once.) a =+ b is a = (+b), i.e. assigning the unary + of b to a. Examples: int a = 15; int b = -5; a += b; // a is now 10 … Read more
_ is indeed a very popular choice for “a name which doesn’t matter” — it’s a legal name, visually unobtrusive, etc. However sometimes these very qualities can hinder you. For example, the GNU gettext module for I18N and L10N, which is part of Python’s standard library, idiomatically uses _ very differently, with idioms such as…: … Read more
Try digit separator: int i = 1’000’000’000; This feature is introduced since C++14. It uses single quote (‘) as digit separator. Also see: Why was the space character not chosen for C++14 digit separators? Generalizing Overloading for C++2000 (April’s joke by the father of C++ himself)