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Why are preprocessor macros evil and what are the alternatives?
I have always asked this but I have never received a really good answer; I think that almost any programmer before even writing the first "Hello World" had encountered a phrase like "macro should never be used", "macro are evil" and so on, my question is: why? With the new C++11 is there a real alte...
Convert int to char in java
Below is a code snippet,
15 Answers
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MySQL Update Inner Join tables query
I have no idea what the problem is. Using MySQL 5.0 I get a compile error when attempting to run the following MySQL update query:
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How to modify list entries during for loop?
...rings, and I want to strip the strings themselves. Does replacement of mutable values count as modification?
9 Answers
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How can I join elements of an array in Bash?
If I have an array like this in Bash:
30 Answers
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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
...g summarise with plyr 's ddply function, empty categories are dropped by default. You can change this behavior by adding .drop = FALSE . However, this doesn't work when using summarise with dplyr . Is there another way to keep empty categories in the result?
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Pandas groupby: How to get a union of strings
... df = read_csv(StringIO(data),sep='\s+')
In [5]: df
Out[5]:
A B C
0 1 0.749065 This
1 2 0.301084 is
2 3 0.463468 a
3 4 0.643961 random
4 1 0.866521 string
5 2 0.120737 !
In [6]: df.dtypes
Out[6]:
A int64
B float64
C object
dtype: obj...
Easy way to concatenate two byte arrays
What is the easy way to concatenate two byte arrays?
12 Answers
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What's the difference between HEAD^ and HEAD~ in Git?
When I specify an ancestor commit object in Git, I'm confused between HEAD^ and HEAD~ .
15 Answers
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What's the difference between array_merge and array + array?
A fairly simple question. What's the difference between:
9 Answers
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