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When should I use the Visitor Design Pattern? [closed]
...dmit, I just don't get it. I read the wikipedia article for the pattern and I understand its mechanics but I'm still confused as to when I'd use it.
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What's the difference between ConcurrentHashMap and Collections.synchronizedMap(Map)?
... properly).
Use the second option if you need to ensure data consistency, and each thread needs to have an up-to-date view of the map. Use the first if performance is critical, and each thread only inserts data to the map, with reads happening less frequently.
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Stored procedure slow when called from web, fast from Management Studio
...in the past, so I'm eager to see a resolution to this question. Aaron Bertrand's comment on the OP led to Query times out when executed from web, but super-fast when executed from SSMS, and while the question is not a duplicate, the answer may very well apply to your situation.
In essence, it sound...
Asking the user for input until they give a valid response
...put the input method in a while loop. Use continue when you get bad input, and break out of the loop when you're satisfied.
When Your Input Might Raise an Exception
Use try and except to detect when the user enters data that can't be parsed.
while True:
try:
# Note: Python 2.x users s...
Which is the best Linux C/C++ debugger (or front-end to gdb) to help teaching programming? [closed]
...("lite" meaning no pointers, no classes, just plain old C, plus references and STL string and vectors). Students have no previous experience in programming, so I believe that using an interactive debugger would help them understand program flow, variables, and recursion.
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How to remove a file from the index in git?
... from the repo, add the relevant files or directories to .gitignore, stage and commit as normal. They'll be gone from the repo but remain untouched in your local tree, and you won't accidentally check them in again.
– Ionoclast Brigham
Dec 7 '14 at 6:27
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SQL Server Installation - What is the Installation Media Folder?
...8. I have installed .NET framework 3.5.
Then I got folder SQL Server 2008 and performed following steps-
10 Answers
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How to preventDefault on anchor tags?
...ATE: I've since changed my mind on this solution. After more development and time spent working on this, I believe a better solution to this problem is to do the following:
<a ng-click="myFunction()">Click Here</a>
And then update your css to have an extra rule:
a[ng-click]{
cu...
What is the equivalent of the C# 'var' keyword in Java?
...possible in Java (all Types had names, even if they were extremely verbose and unweildy). I do not know if this has changed in the mean time.
var is not the same as dynamic. variables are still 100% statically typed. This will not compile:
var myString = "foo";
myString = 3;
var is also useful whe...
getViewTypeCount and getItemViewType methods of ArrayAdapter
Can somebody in plain words explain me the usage of getViewTypeCount() and getItemViewType() methods of ArrayAdapter ?
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