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Why does ++[[]][+[]]+[+[]] return the string “10”?
...array ([]). Due to references it's wrong to say [[]][0] === [], but let's call the inner array A to avoid the wrong notation.
++ before its operand means “increment by one and return the incremented result”. So ++[[]][0] is equivalent to Number(A) + 1 (or +A + 1).
Again, we can simplify the me...
Why isn't sizeof for a struct equal to the sum of sizeof of each member?
... errors.
Here's an example using typical settings for an x86 processor (all used 32 and 64 bit modes):
struct X
{
short s; /* 2 bytes */
/* 2 padding bytes */
int i; /* 4 bytes */
char c; /* 1 byte */
/* 3 padding bytes */
};
struct Y
{
int i; /* 4...
Rename specific column(s) in pandas
I've got a dataframe called data . How would I rename the only one column header? For example gdp to log(gdp) ?
5 Answe...
Relative paths in Python
..., you want to do something like this:
import os
dirname = os.path.dirname(__file__)
filename = os.path.join(dirname, 'relative/path/to/file/you/want')
This will give you the absolute path to the file you're looking for. Note that if you're using setuptools, you should probably use its package re...
How to force use of overflow menu on devices with menu button
I'd like to have all of the menu items that don't fit into the ActionBar go into the overflow menu (the one that is reached from the Action Bar not the menu button) even on devices that do have a Menu button . This seems much more intuitive for users than throwing them into a separate menu list th...
Two-way encryption: I need to store passwords that can be retrieved
...
Personally, I would use mcrypt like others posted. But there is much more to note...
How do I encrypt and decrypt a password in PHP?
See below for a strong class that takes care of everything for you:
What is the safest algorit...
Pandas percentage of total with groupby
... is a table of some kind, so 100 * x doesn't intuitively make sense (especially when some of the cells contain strings like AZ, ...).
– dhardy
Feb 6 '15 at 9:42
6
...
iOS开发调试技巧总结 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...(format,...)do{\
fprintf(stderr,"%s\n",\
[[[NSStringstringWithUTF8String:__FILE__]lastPathComponent]UTF8String],\
__LINE__,__func__);\
(NSLog)((format),##__VA_ARGS__);\
fprintf(stderr,"-------\n");\
}while(0)
@interfaceViewController
@end
@implementationViewController
-(void)viewDi...
Restoring MySQL database from physical files
...mysql data directory is quick and easy, but figuring out, before that, why all my resoterd DBs seemed to have no tables took a bit longer.
– Edurne Pascual
Sep 26 '12 at 15:41
10
...
What kind of leaks does automatic reference counting in Objective-C not prevent or minimize?
... platforms, memory leaks are often caused by unreleased pointers. Traditionally, it has always been of utmost importance to check your allocs, copies and retains to make sure each has a corresponding release message.
...