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When to use wrapper class and primitive type
When I should go for wrapper class over primitive types? Or On what circumstance I should choose between wrapper / Primitive types?
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What does map(&:name) mean in Ruby?
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It's shorthand for tags.map(&:name.to_proc).join(' ')
If foo is an object with a to_proc method, then you can pass it to a method as &foo, which will call foo.to_proc and use that as the method's block.
The Symbol#t...
Ukkonen's suffix tree algorithm in plain English
I feel a bit thick at this point. I've spent days trying to fully wrap my head around suffix tree construction, but because I don't have a mathematical background, many of the explanations elude me as they start to make excessive use of mathematical symbology. The closest to a good explanation that ...
How do I convert from int to String?
...nteger.toString(i) or String.valueOf(i).
The concatenation will work, but it is unconventional and could be a bad smell as it suggests the author doesn't know about the two methods above (what else might they not know?).
Java has special support for the + operator when used with strings (see the d...
How to auto-indent code in the Atom editor?
How do you auto-indent your code in the Atom editor? In other editors you can usually select some code and auto-indent it.
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Why do we use Base64?
...e used for different purposes.
When you encode text in ASCII, you start with a text string and convert it to a sequence of bytes.
When you encode data in Base64, you start with a sequence of bytes and convert it to a text string.
To understand why Base64 was necessary in the first place we need...
Python subprocess.Popen “OSError: [Errno 12] Cannot allocate memory”
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As a general rule (i.e. in vanilla kernels), fork/clone failures with ENOMEM occur specifically because of either an honest to God out-of-memory condition (dup_mm, dup_task_struct, alloc_pid, mpol_dup, mm_init etc. croak), or because security_vm_enough_memory_mm failed you while enforcing t...
Any idea why I need to cast an integer literal to (int) here?
...tract 128 from (Integer) instead of casting -128 to Integer. Add () to fix it
Integer i3 = (Integer) -128; // doesn't compile
Integer i3 = (Integer) (-128); // compiles
According to BoltClock in the comments the cast to int works as intended, because it is a reserved word and therefore can't be ...
How do I create a new Swift project without using Storyboards?
...vigationController?
Swift classes require non-optional properties to be initialized during the instantiation:
Classes and structures must set all of their stored properties to an appropriate initial value by the time an instance of that class or structure is created. Stored properties cannot be le...
What is the yield keyword used for in C#?
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The yield keyword actually does quite a lot here.
The function returns an object that implements the IEnumerable<object> interface. If a calling function starts foreaching over this object, the function is called again until it "yields". This is syntac...