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What's the difference between String(value) vs value.toString()
...cation, the [[DefaultValue]] internal operation.
Briefly summarized, when converting from Object-to-String, the following steps are taken:
If available, execute the toString method.
If the result is a primitive, return result, else go to Step 2.
If available, execute the valueOf method.
If t...
MySQL indexes - what are the best practices?
...nd all the rows where column starts with "foo", and then need to scan that intermediate rowset to find the subset that contains "bar". SELECT ... WHERE column LIKE '%bar%' can't use the index. I hope you can see why.
Finally, you need to start thinking about indexes on more than one column. The ...
Mean per group in a data.frame [duplicate]
...0.33333
#3 Cat 2 44.66667 54.00000
Using data.table:
# At first, I convert the data.frame to data.table and then I group it
setDT(d)
d[, .(Rate1 = mean(Rate1), Rate2 = mean(Rate2)), by = .(Name)]
# Name Rate1 Rate2
#1: Aira 16.33333 47.00000
#2: Ben 31.33333 50.33333
#3: Cat 44.66...
How to set standard encoding in Visual Studio
...files comform to set rules. Note that Visual Studio does not automatically convert all your files but do its bit when you work with files in IDE (open and save).
What next
While you could have a Visual-studio-wide setup, I strongly suggest to still include an EditorConfig root to your solution ve...
What does “Content-type: application/json; charset=utf-8” really mean?
...", "UTF-8");) for me and I had to retrieve response data as draw bytes and convert it into String using UTF-8. So, it is recommended to be explicit and avoid assumption of default value.
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How do I change the formatting of numbers on an axis with ggplot?
... E.g.: (3x10^+2 -> 3x10^2) l <- gsub("e\\+","e",l) and after it: # convert 1x10^ or 1.000x10^ -> 10^ l <- gsub("\\'1[\\.0]*\\'\\%\\*\\%", "", l) to make it in format usually used in papers.
– John_West
Feb 23 '16 at 14:08
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What's best SQL datatype for storing JSON string?
...is based on nvarchar) will be introduced, as well as a FOR JSON command to convert output from a query into JSON format
Update #2: in the final product, Microsoft did not include a separate JSON datatype - instead, there are a number of JSON-functions (to package up database rows into JSON, or to p...
A type for Date only in C# - why is there no Date type?
...is very careful to ignore the time, and is also very careful not to try to convert to and from UTC or other time zones.
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Copy constructor versus Clone()
...e Clone() method on ICloneable should be a deep or shallow clone, thus the interface is semantically broken as your callers won't know whether the call will deep or shallow clone the object.
Instead, you should define your own IDeepCloneable (and IShallowCloneable) interfaces with DeepClone() (and ...
Join vs. sub-query
... Yes, most databases therefore includes it as an optimization step to convert subqueries into joins when it is analyzing your query.
– Cine
May 28 '10 at 9:38
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