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Detecting an undefined object property
... check if an object does not actually have such a property, and will therefore return undefined by default when you try and access it:
if(!o.hasOwnProperty('myProperty')) {
alert("myProperty does not exist");
}
To check if the value associated with an identifier is the special value undefined, ...
WebSockets protocol vs HTTP
...
1) Why is the WebSockets protocol better?
WebSockets is better for situations that involve low-latency communication especially for low latency for client to server messages. For server to client data you can get fairly low latency using long-held connections and chunked transfer. However...
compareTo() vs. equals()
When testing for equality of String 's in Java I have always used equals() because to me this seems to be the most natural method for it. After all, its name already says what it is intended to do. However, a colleague of mine recently told me had been taught to use compareTo() == 0 instead of ...
How can I reset or revert a file to a specific revision?
...ash of the commit you want is c5f567:
git checkout c5f567 -- file1/to/restore file2/to/restore
The git checkout man page gives more information.
If you want to revert to the commit before c5f567, append ~1 (where 1 is the number of commits you want to go back, it can be anything):
git checkout ...
Utility classes are evil? [closed]
...actly evil, but they can violate the principles that compose a good object-oriented design. In a good object-oriented design, most classes should represent a single thing and all of its attributes and operations. If you are operating on a thing, that method should probably be a member of that thing....
git: Switch branch and ignore any changes without committing
I was working on a git branch and was ready to commit my changes, so I made a commit with a useful commit message. I then absentmindedly made minor changes to the code that are not worth keeping. I now want to change branches, but git gives me,
...
SQL Server database backup restore on lower version
How to restore a higher version SQL Server database backup file onto a lower version SQL Server?
13 Answers
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Is < faster than
...risons will be typically implemented in two machine instructions:
A test or cmp instruction, which sets EFLAGS
And a Jcc (jump) instruction, depending on the comparison type (and code layout):
jne - Jump if not equal --> ZF = 0
jz - Jump if zero (equal) --> ZF = 1
jg - Jump if greater -->...
Lock-free multi-threading is for real threading experts
...operation
retry if it fails
(*optional: depends on the data structure/algorithm)
The last bit is eerily similar to a spinlock. In fact, it is a basic spinlock. :)
I agree with @nobugz on this: the cost of the interlocked operations used in lock-free multi-threading is dominated by the cache and m...
Tomcat: How to find out running tomcat version
I'm trying to get Appfuse + tomcat + jRebel working.
27 Answers
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