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What is the difference between the | and || or operators?
I have always used || (two pipes) in OR expressions, both in C# and PHP. Occasionally I see a single pipe used: | . What is the difference between those two usages? Are there any caveats when using one over the other or are they interchangeable?
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Check whether a path is valid in Python without creating a file at the path's target
I have a path (including directory and file name).
I need to test if the file-name is a valid, e.g. if the file-system will allow me to create a file with such a name.
The file-name has some unicode characters in it.
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Evaluate empty or null JSTL c tags
How can I validate if a String is null or empty using the c tags of JSTL ?
8 Answers
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IF… OR IF… in a windows batch file
Is there a way to write an IF OR IF conditional statement in a windows batch-file?
14 Answers
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Is there an easy way to check the .NET Framework version?
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Something like this should do it. Just grab the value from the registry
For .NET 1-4:
Framework is the highest installed version, SP is the service pack for that version.
RegistryKey installed_versions = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\NET Framework Setup\NDP");
string[] ve...
When can I use a forward declaration?
I am looking for the definition of when I am allowed to do forward declaration of a class in another class's header file:
1...
Combining “LIKE” and “IN” for SQL Server [duplicate]
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Effectively, the IN statement creates a series of OR statements... so
SELECT * FROM table WHERE column IN (1, 2, 3)
Is effectively
SELECT * FROM table WHERE column = 1 OR column = 2 OR column = 3
And sadly, that is the route you'll have to take with your LIKE statement...
What is a magic number, and why is it bad? [closed]
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A magic number is a direct usage of a number in the code.
For example, if you have (in Java):
public class Foo {
public void setPassword(String password) {
// don't do this
if (password.length() > 7) {
throw new InvalidArgumentException("passwo...
How can I check if a string is null or empty in PowerShell?
Is there a built-in IsNullOrEmpty -like function in order to check if a string is null or empty, in PowerShell?
11 Answers...
What is the strict aliasing rule?
When asking about common undefined behavior in C , people sometimes refer to the strict aliasing rule.
What are they talking about?
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