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String is immutable. What exactly is the meaning? [duplicate]
...are immutable? Well to your surprise, it is.
When the above statement is executed, the VM takes the value of String str, i.e. "knowledge" and appends " base", giving us the value "knowledge base". Now, since Strings are immutable, the VM can't assign this value to str, so it creates a new String ob...
Random row selection in Pandas dataframe
...
Something like this?
import random
def some(x, n):
return x.ix[random.sample(x.index, n)]
Note: As of Pandas v0.20.0, ix has been deprecated in favour of loc for label based indexing.
sha...
How to retrieve a single file from a specific revision in Git?
...
Using git show
To complete your own answer, the syntax is indeed
git show object
git show $REV:$FILE
git show somebranch:from/the/root/myfile.txt
git show HEAD^^^:test/test.py
The command takes the usual style of revision, meaning you can use any of the following:
branch name...
More than 10 lines in a node.js stack error?
... debugger always displays full stack (bt command).
– x-yuri
Nov 17 '17 at 18:32
And apparently, stack trace doesn't fo...
Reference: Comparing PHP's print and echo
...es sure that the return value for print is 1, as follows:
ZVAL_LONG(&EX_T(opline->result.var).tmp_var, 1);
(see here for reference)
The return value is a convenience should one wish to use print in a conditional expression. Why 1 and not 100? Well in PHP the truthiness of 1 or 100 is the...
FFmpeg on Android
...Android. Now I have to build either an application like RockPlayer or use existing Android multimedia framework to invoke FFmpeg.
...
What are allowed characters in cookies?
...cookie_spec the entire NAME=VALUE string is:
a sequence of characters excluding semi-colon, comma and white space.
So - should work, and it does seem to be OK in browsers I've got here; where are you having trouble with it?
By implication of the above:
= is legal to include, but potentially...
Using the rJava package on Win7 64 bit with R
.... However note that:
To use rJava in 32-bit R, you need Java for Windows x86
To use rJava in 64-bit R, you need Java for Windows x64
To build or check R packages with multi-arch (the default) you need to install both Java For Windows x64 as well as Java for Windows x86. On Win 64, the former inst...
Which C++ idioms are deprecated in C++11?
...ass support for rvalue references.
Safe bool: This was mentioned earlier. Explicit operators of C++11 obviate this very common C++03 idiom.
Shrink-to-fit: Many C++11 STL containers provide a shrink_to_fit() member function, which should eliminate the need swapping with a temporary.
Temporary Base Cl...
Initialising mock objects - MockIto
...Runner :
JUnit 4.5 runner initializes mocks annotated with Mock, so that explicit usage of MockitoAnnotations.initMocks(Object) is not necessary. Mocks are initialized before each test method.
The first solution (with the MockitoAnnotations.initMocks) could be used when you have already configure...