You don’t need the constant, but I don’t think you can eliminate symbol-to-string: class Example attr_reader :name, :age def initialize args args.each do |k,v| instance_variable_set(“@#{k}”, v) unless v.nil? end end end #=> nil e1 = Example.new :name => ‘foo’, :age => 33 #=> #<Example:0x3f9a1c @name=”foo”, @age=33> e2 = Example.new :name => ‘bar’ #=> #<Example:0x3eb15c @name=”bar”> … Read more
Apache Commons has the DurationFormatUtils class for applying a specified format to a time duration. So, something like: long time = System.currentTimeMillis(); //do something that takes some time… long completedIn = System.currentTimeMillis() – time; DurationFormatUtils.formatDuration(completedIn, “HH:mm:ss:SS”);
You might be interested in the Named Parameter Idiom. To summarize, create a class that holds the values you want to pass to your constructor(s). Add a method to set each of those values, and have each method do a return *this; at the end. Have a constructor in your class that takes a const … Read more
Addressing the proposed solution from dmckee: While some versions of Bash may allow hyphens in function names, others (MacOS X) do not. I don’t see a need to use return immediately before the end of the function. I don’t see the need for all the semi-colons. I don’t see why you have path-element-by-pattern export a … Read more
Probably the shortest would be str(s or ”) Because None is False, and “x or y” returns y if x is false. See Boolean Operators for a detailed explanation. It’s short, but not very explicit.
Most of the times it is easier (and cheaper) to make the first iteration the special case instead of the last one: first = True for data in data_list: if first: first = False else: between_items() item() This will work for any iterable, even for those that have no len(): file = open(‘/path/to/file’) for line … Read more
My way (without additional branch) is: const auto separator = “WhatYouWantHere”; const auto* sep = “”; for(const auto& item : items) { std::cout << sep << item; sep = separator; }
A good rule of thumb is for anything that you need to compare in the loop condition against something that is naturally a std::size_t itself. std::size_t is the type of any sizeof expression and as is guaranteed to be able to express the maximum size of any object (including any array) in C++. By extension … Read more
Instead of inducing performance overhead, why not use an extension method to alleviate both problems: public static void Raise(this EventHandler handler, object sender, EventArgs e) { if(handler != null) { handler(sender, e); } } Once defined, you never have to do another null event check again: // Works, even for null events. MyButtonClick.Raise(this, EventArgs.Empty);
If you are accessing files, EAFP is more reliable than LBYL, because the operations involved in LBYL are not atomic, and the file system might change between the time you look and the time you leap. Actually, the standard name is TOCTOU – Time of Check, Time of Use; bugs caused by inaccurate checking are … Read more