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How do I check if an object has a specific property in JavaScript?
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I'm really confused by the answers that have been given - most of them are just outright incorrect. Of course you can have object properties that have undefined, null, or false values. So simply reducing the property check to typeo...
How to change the session timeout in PHP?
...cted immediately but only whenever the session GC kicks in.
GC is a potentially expensive process, so typically the probability is rather small or even zero (a website getting huge numbers of hits will probably forgo probabilistic GC entirely and schedule it to happen in the background every X minut...
Extract value of attribute node via XPath
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With xqilla it was necessary to call xs:string. I wonder why.
– krlmlr
Jul 22 '13 at 20:00
1
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Getter and Setter?
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That's not really setter and getter. Typically I need for each property different implementation of getter!
– sumid
Feb 16 '13 at 0:59
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Are types like uint32, int32, uint64, int64 defined in any stdlib header?
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This answer is wrong. All of the above are only available if an exact width type of that size (no padding) exists in the implementation. Even if not, however, the types int_leastNN_t and uint_leastNN_t for NN 8, 16, 32, and 64 must always exist. C...
undefined reference to boost::system::system_category() when compiling
...raries. I have the 1.46-dev Boost libraries from the Ubuntu Repository installed, but I get an error when compiling the program.
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Use cases for the 'setdefault' dict method
...e case: Grouping items (in unsorted data, else use itertools.groupby)
# really verbose
new = {}
for (key, value) in data:
if key in new:
new[key].append( value )
else:
new[key] = [value]
# easy with setdefault
new = {}
for (key, value) in data:
group = new.setdefault(k...
Timeout on a function call
I'm calling a function in Python which I know may stall and force me to restart the script.
18 Answers
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How do you query for “is not null” in Mongo?
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This will return all documents with a key called "IMAGE URL", but they may still have a null value.
db.mycollection.find({"IMAGE URL":{$exists:true}});
This will return all documents with both a key called "IMAGE URL" and a non-null value.
d...
Why do we always prefer using parameters in SQL statements?
...uld be
SELECT empSalary from employee where salary = 0 or 1=1
whereby all empSalaries would be returned.
Further, a user could perform far worse commands against your database, including deleting it If they wrote 0; Drop Table employee:
SELECT empSalary from employee where salary = 0; Drop Ta...