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What is the difference between cout, cerr, clog of iostream header in c++? When to use which one?
... Depends I guess, on more reasons than I can list and it has to be decided from case to case.
– Some programmer dude
Aug 11 '17 at 15:48
3
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What are best practices that you use when writing Objective-C and Cocoa? [closed]
...aching of responses.
Also of interest, are some good iPhone specific tips from Joseph Mattiello (received in an iPhone mailing list). There are more, but these were the most generally useful I thought (note that a few bits have now been slightly edited from the original to include details offered ...
java.lang.UnsupportedClassVersionError: Bad version number in .class file?
...ting this error when I include an opensource library that I had to compile from source. Now, all the suggestions on the web indicate that the code was compiled in one version and executed in another version (new on old). However, I only have one version of JRE on my system. If I run the commands:...
How to uncommit my last commit in Git [duplicate]
...
@Jefromi: every answer in this question is totally wrong to emphasize --hard, the --soft, is necessary for it to be "uncommit last commit", a --hard will not only uncommit but also destroy your commit. I nearly destroyed a whol...
How to read all files in a folder from Java?
...e/you/Desktop");
listFilesForFolder(folder);
Files.walk API is available from Java 8.
try (Stream<Path> paths = Files.walk(Paths.get("/home/you/Desktop"))) {
paths
.filter(Files::isRegularFile)
.forEach(System.out::println);
}
The example uses try-with-resources patte...
cartesian product in pandas
... you can produce a cartesian product using merge (like you would in SQL).
from pandas import DataFrame, merge
df1 = DataFrame({'key':[1,1], 'col1':[1,2],'col2':[3,4]})
df2 = DataFrame({'key':[1,1], 'col3':[5,6]})
merge(df1, df2,on='key')[['col1', 'col2', 'col3']]
Output:
col1 col2 col3
0 ...
How can I lock a file using java (if possible)
... opens a file using a FileReader. How can I prevent another (Java) process from opening this file, or at least notify that second process that the file is already opened? Does this automatically make the second process get an exception if the file is open (which solves my problem) or do I have to ex...
How can I check file size in Python?
....stat. You can get it by either using pathlib (Python 3.4+):
>>> from pathlib import Path
>>> Path('somefile.txt').stat()
os.stat_result(st_mode=33188, st_ino=6419862, st_dev=16777220, st_nlink=1, st_uid=501, st_gid=20, st_size=1564, st_atime=1584299303, st_mtime=1584299400, st_ct...
When to use PNG or JPG in iPhone development?
... extra CPU energy to display. However, large PNGs may take longer to read from storage than more compressed image formats, and thus be slower to display.
JPG's are smaller to store, but lossy (amount depends on compression level), and to display them requires a much more complicated decoding algor...
How to override trait function and call it from the overridden function?
...n calc($v) {
return parent::calc($v*3);
}
}
// .... other code from above
print (new MyTraitChildClass())->calc(2); // will print 8 (2*3 + 2)
You can also provide for ways to override, but still access the trait method as follows:
trait A {
function trait_calc($v) {
ret...