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RegEx to parse or validate Base64 data
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^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$
This one is good, but will match an empty String
This one does not match empty string :
^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$
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Cannot make a static reference to the non-static method
...n the type directly, say like this:
The previous statement is not correct. One can also refer to static fields with an object reference like myObject.staticMethod() but this is discouraged because it does not make it clear that they are class variables.
... = SomeClass.final
And the two cannot w...
When should I use Lazy?
...revent user latency in high throughput, low latency systems. This is just one of the many reasons to not "always" use Lazy.
– Derrick
Sep 30 '14 at 12:34
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Rails: How does the respond_to block work?
...mental than some of the answers I found here. This may or may not help someone.
respond_to is a method on the superclass ActionController.
it takes a block, which is like a delegate. The block is from do until end, with |format| as an argument to the block.
respond_to executes your block, passing ...
Add … if string is too long PHP [duplicate]
...ld in my MySQL database, and I access the database on two different pages, one page I display the whole field, but on the other, I just want to display the first 50 characters. If the string in the description field is less than 50 characters, then it won't show ... , but if it isn't, I will show ....
Real World Example of the Strategy Pattern
...e", but it's not yet clear what that rule will be, and we may think of new ones.
Games: We want player to either walk or run when he moves, but maybe in the future, he should also be able to swim, fly, teleport, burrow underground, etc.
Storing information: We want the application to store informati...
Set up git to pull and push all branches
... to push and pull all the branches by default, including the newly created ones.
8 Answers
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Why should Java ThreadLocal variables be static
...t, etc. You don't want them also sub-scoped to the instance of the class.
One web request => one Persistence session.
Not one web request => one persistence session per object.
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improv...
Why is creating a Thread said to be expensive?
...e possibly cheaper to create, but you pay for it in other areas.)
I've done a bit of digging to see how a Java thread's stack really gets allocated. In the case of OpenJDK 6 on Linux, the thread stack is allocated by the call to pthread_create that creates the native thread. (The JVM does not p...
What part of Hindley-Milner do you not understand?
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: and ∈ are very similar, in that they mean that one thing is contained in another thing – a set contains elements, and a type contains values, in a sense. The crucial difference is that x ∈ S means that a set S literally contains an element x, whereas Γ ⊢ x : T mean...