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What is a NullReferenceException, and how do I fix it?
... to find out where the reference is or isn't set, right-click its name and select "Find All References". You can then place a breakpoint at every found location and run your program with the debugger attached. Every time the debugger breaks on such a breakpoint, you need to determine whether you exp...
Create an Array of Arraylists
...yList<String>[] group = new ArrayList[4])? What extra good doe sthe cast do?
– cellepo
Mar 22 '16 at 21:12
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Hibernate SessionFactory vs. JPA EntityManagerFactory
...EntityManager translate entity state transitions into SQL statements, like SELECT, INSERT, UPDATE, and DELETE.
Hibernate vs. JPA bootstrap
When bootstrapping a JPA or Hibernate application, you have two choices:
You can bootstrap via the Hibernate native mechanism, and create a SessionFactory vi...
C# - Keyword usage virtual+override vs. new
...a Bar, but we are storing it in a variable of type Foo (this is similar to casting it)
Then the result will be as follows, depending on whether you used virtual/override or new when declaring your classes.
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How to convert String object to Boolean Object?
...it has a performance cost.
I suggest to use it only when you would have to cast yourself, not when the cast is avoidable.
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Why doesn't c++ have &&= or ||= for booleans?
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The only way to get an invalid value into a bool is by using reinterpret_cast on pointers:
int i = 2;
bool b = *reinterpret_cast<bool*>(&i);
b |= true; // MAY yield 3 (but doesn’t on my PC!)
But since this code results in undefined behaviour anyway, we may safely ignore this potenti...
Using a Single Row configuration table in SQL Server database. Bad idea?
...iguration settings.
So when you want to retrieve the value you could do:
SELECT value FROM configurationTable
WHERE ApplicationGroup = 'myappgroup'
AND keyDescription = 'myKey';
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Check if Key Exists in NameValueCollection
...but it could be current culture or invariant culture
|| @this.Keys.Cast<string>().Contains(key, StringComparer.OrdinalIgnoreCase);
}
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Java array reflection: isArray vs. instanceof
...er an object is an array.
Generally, you test an object's type before downcasting to a particular type which is known at compile time. For example, perhaps you wrote some code that can work with a Integer[] or an int[]. You'd want to guard your casts with instanceof:
if (obj instanceof Integer[]) ...
How to programmatically round corners and set random background colors
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If "v" is the TextView than v.getBackground() will cast "java.lang.ClassCastException: android.graphics.drawable.StateListDrawable cannot be cast to android.graphics.drawable.GradientDrawable" Was this realy working back in '13?
– sonavolob
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