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Why is there no logical xor in JavaScript?
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JavaScript traces its ancestry back to C, and C does not have a logical XOR operator. Mainly because it's not useful. Bitwise XOR is extremely useful, but in all my years of programming I have never needed a logical XOR.
If you have two boolean variables you can mim...
Avoiding if statement inside a for loop?
...e penalty.
The idea of passing in what varies is ubiquitous in the C++ Standard Library. It is called the strategy pattern.
If you are allowed to use C++11, you can do something like this:
#include <iostream>
#include <set>
#include <vector>
template <typename Container, ty...
Dynamically generating a QR code with PHP [closed]
...rate,
the chl is the url-encoded string you want to change into a QR code, and
the choe is the (optional) encoding.
The link, above, gives more detail, but to use it just have the src of an image point to the manipulated value, like so:
<img src="https://chart.googleapis.com/chart?chs=300x300&...
Break when exception is thrown
...l Studio has an option to break automatically into the debugger when an unhandled exception is thrown, does Eclipse have similar functionality?
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How to install PostgreSQL's pg gem on Ubuntu?
...ting extended state information... Done (Reading database ... 166183 files and directories currently installed.) Removing bison ... Removing libnss3-dev ... Removing libnspr4-dev ... Removing libqt4-core ... Removing libqt4-test ... Removing libsqlite3-dev ... Processing triggers for man-db ..
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Constant pointer vs Pointer to constant [duplicate]
...erally I would prefer the declaration like this which make it easy to read and understand (read from right to left):
int const *ptr; // ptr is a pointer to constant int
int *const ptr; // ptr is a constant pointer to int
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Crontab - Run in directory
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All jobs are executed by a shell, so start that shell snippet by a command to change the directory.
cd /path/to/directory && ./bin/myapp
Concerning the use of && instead of ;: normally it doesn't make a difference, but if the cd command fails (e.g. because the directory doesn'...
How to add lines to end of file on Linux
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It depends on the last added line, not your current command. When you do the $ echo "foobar" >> file,the newline is already there. If you do $ echo -n "foobar" >> file, you won't append the newline to the end of the line, so you'll write in the same line.
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Profiling Vim startup time
...with how long Vim takes to start now, so I’d like to profile its startup and see which of the many plugins I have are responsible.
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validation custom message for rails 3
... edited Mar 4 '15 at 3:20
Andrew Hendrie
5,08722 gold badges3434 silver badges6262 bronze badges
answered Mar 22 '11 at 4:33
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