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Rename a file using Java
Can we rename a file say test.txt to test1.txt ?
14 Answers
14
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Implications of foldr vs. foldl (or foldl')
...er terminates. (Note: repeat False creates an infinite list where every element is False.)
On the other hand, foldl' is tail recursive and strict. If you know that you'll have to traverse the whole list no matter what (e.g., summing the numbers in a list), then foldl' is more space- (and probably t...
What happens if you don't commit a transaction to a database (say, SQL Server)?
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mmm, ok I figure out this was creating some sort of lock. I wasn't sure that closing the connection would actually get me out of this state. the problem was that I was getting an error when I try to commit. now I closed the connection and it all worked.
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Is it possible to program iPhone in C++
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can you recommend a website or book that is aimed at experienced C++ programmers to learn Objective-C? I managed to mash a few test apps together, but I find the syntax a little backwards and I am sure that I am doing things that lead to ...
How To Launch Git Bash from DOS Command Line?
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Thanks @Endoro! Though @Klas Mellbourn's answer was correct for Powershell, yours is more correct since I'm running from DOS batch file. The addition of the "start" directive causes the program to execute asynchronously, which is exactly what I need! Th...
How to read json file into java with simple JSON library
...r (Object o : a)
{
JSONObject person = (JSONObject) o;
String name = (String) person.get("name");
System.out.println(name);
String city = (String) person.get("city");
System.out.println(city);
String job = (String) person.get("job");
System.out.println(job);
JSO...
Equivalent of .try() for a hash to avoid “undefined method” errors on nil? [duplicate]
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You forgot to put a . before the try:
@myvar = session[:comments].try(:[], @comment.id)
since [] is the name of the method when you do [@comment.id].
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How to hide reference counts in VS2013?
Visual Studio 2013 introduced a new feature where it shows you how many times each of your methods are used.
5 Answers
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How to select the rows with maximum values in each group with dplyr? [duplicate]
...%>%
arrange(A,B,C)
Seems to work:
identical(
as.data.frame(result),
ddply(df, .(A, B), function(x) x[which.max(x$value),])
)
#[1] TRUE
As pointed out in the comments, slice may be preferred here as per @RoyalITS' answer below if you strictly only want 1 row per group. This answ...
How to get script of SQL Server data? [duplicate]
I'm looking for a way to do something analogous to the MySQL dump from SQL Server. I need to be able to pick the tables and export the schema and the data (or I can export the schema via SQL Server Management Studio and export the data separately somehow).
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