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How to compare variables to undefined, if I don’t know whether they exist? [duplicate]
In JavaScript you can declare a variable and if it’s undefined , you can check variable == undefined ; I know that, but how can you compare a value that you don’t know yet if it’s in memory?
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How do I read a text file of about 2 GB? [duplicate]
...the fast, smart log explorer.
I have opened log file of size around 2 GB, and the search is also very fast.
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String formatting named parameters?
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In Python 2.6+ and Python 3, you might choose to use the newer string formatting method.
print('<a href="{0}">{0}</a>'.format(my_url))
which saves you from repeating the argument, or
print('<a href="{url}">{url}</a&...
JavaScript % (modulo) gives a negative result for negative numbers
...ug". The modulo operation is not very well defined over negative numbers, and different computing environments handle it differently. Wikipedia's article on the modulo operation covers it pretty well.
– Daniel Pryden
Dec 17 '10 at 4:08
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SQL Server 2008: How to query all databases sizes?
I have MS SQL 2008 R2, 500 databases.
What is the most efficient, easiest and 'modern' way to query all databases sizes.
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SQLAlchemy: how to filter date field?
...our filter is excluding all records: you should change the <= for >= and vice versa:
qry = DBSession.query(User).filter(
and_(User.birthday <= '1988-01-17', User.birthday >= '1985-01-17'))
# or same:
qry = DBSession.query(User).filter(User.birthday <= '1988-01-17').\
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What is the use for IHttpHandler.IsReusable?
I'm writing a IHttpHandler and I'll need to implement a IsReusable property. When I look at the MSDN documentation it says:
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How do I check in SQLite whether a table exists?
... the complete query is:
SELECT name FROM sqlite_master WHERE type='table' AND name='{table_name}';
Where {table_name} is the name of the table to check.
Documentation section for reference: Database File Format. 2.6. Storage Of The SQL Database Schema
This will return a list of tables with the...
Is there any performance reason to declare method parameters final in Java?
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The final keyword does not appear in the class file for local variables and parameters, thus it cannot impact the runtime performance. It's only use is to clarify the coders intent that the variable not be changed (which many consider dubious reason for its usage), and dealing with anonymous inn...
Get the position of a div/span tag
... the page. Basically you have to loop up through all the element's parents and add their offsets together.
function getPos(el) {
// yay readability
for (var lx=0, ly=0;
el != null;
lx += el.offsetLeft, ly += el.offsetTop, el = el.offsetParent);
return {x: lx,y: ly};
}
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