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Is the order of elements in a JSON list preserved?
...
Practically speaking, if the keys were of type NaN, the browser will not change the order.
The following script will output "One", "Two", "Three":
var foo={"3":"Three", "1":"One", "2":"Two"};
for(bar in foo) {
alert(foo[bar]);...
“Least Astonishment” and the Mutable Default Argument
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Actually, this is not a design flaw, and it is not because of internals, or performance.
It comes simply from the fact that functions in Python are first-class objects, and not only a piece of code.
As soon as you get to think i...
Set a persistent environment variable from cmd.exe
...ferent windows machines, but I don't want to be bothered changing them manually by getting on the properties screen of "My Computer"
...
Using lambda expressions for event handlers
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Really? Interesting - so, if I register two anonymous functions that look the same (w.l.o.g. have an empty body), and then I unregister (using -=) another anonymous function that too has an empty body, it is essentially undefin...
Cannot refer to a non-final variable inside an inner class defined in a different method
...have been cleaned up.
By making lastPrice and price final, they are not really variables anymore, but constants. The compiler can then just replace the use of lastPrice and price in the anonymous class with the values of the constants (at compile time, of course), and you won't have the problem wit...
How does the Brainfuck Hello World actually work?
...ad a decimal ASCII code 97 to memory:
...[0][0][*97*][0][0]...
You generally want to think that way, however the truth is a bit more complex. The truth is BF does not read a character but a byte (whatever that byte is). Let me show you example:
In linux
$ printf ł
prints:
ł
which is spec...
How do I vertically align text in a div?
...; vertical-align: middle;">
<div>
everything is vertically centered in modern IE8+ and others.
</div>
</div>
</div>
It is possible to merge hacks for old browsers (Internet Explorer 6/7) into styles with using # to hide styles from newer brows...
Difference between getAttribute() and getParameter()
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Generally, a parameter is a string value that is most commonly known for being sent from the client to the server (e.g. a form post) and retrieved from the servlet request. The frustrating exception to this is ServletContext init...
How to prevent http file caching in Apache httpd (MAMP)
...d this? Should work in both .htaccess, httpd.conf and in a VirtualHost (usually placed in httpd-vhosts.conf if you have included it from your httpd.conf)
<filesMatch "\.(html|htm|js|css)$">
FileETag None
<ifModule mod_headers.c>
Header unset ETag
Header set Cache-Control "m...
What's a concise way to check that environment variables are set in a Unix shell script?
...is therefore in the Korn Shell, and in the POSIX shells, including specifically Bash.
It is usually documented in the shell's man page in a section called Parameter Expansion. For example, the bash manual says:
${parameter:?word}
Display Error if Null or Unset. If parameter is null or unset, the...