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Array include any value from another array?
... & foods).empty?
As Marc-André Lafortune said in comments, & works in linear time while any? + include? will be quadratic. For larger sets of data, linear time will be faster. For small data sets, any? + include? may be faster as shown by Lee Jarvis' answer -- probably because & alloc...
How do you list the active minor modes in emacs?
...de-list. Finding out whether they're active or not is usually done by checking the variable of the same name. So you can do something like this:
(defun which-active-modes ()
"Give a message of which minor modes are enabled in the current buffer."
(interactive)
(let ((active-modes))
(map...
Macro vs Function in C
...rone because they rely on textual substitution and do not perform type-checking. For example, this macro:
#define square(a) a * a
works fine when used with an integer:
square(5) --> 5 * 5 --> 25
but does very strange things when used with expressions:
square(1 + 2) --> 1 + 2 * 1 + 2 ...
Using current time in UTC as default value in PostgreSQL
I have a column of the TIMESTAMP WITHOUT TIME ZONE type and would like to have that default to the current time in UTC. Getting the current time in UTC is easy:
...
Do you leave parentheses in or out in Ruby? [closed]
... out parenthesis, in general, resist this
temptation.
Parenthesis make the code easier to
follow. General Ruby style is to use
them, except in the following cases:
Always leave out empty parentheses
The parentheses can be left out of a single command that is surrounded by
ERb ...
How to remove the underline for anchors(links)?
Is there anyway (in CSS) to avoid the underline for the text and links introduced in the page .. ?
15 Answers
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How do I load a file into the python console?
...or Python 3) give this a try:
execfile('file.py')
Example usage:
C:\junk>copy con execfile_example.py
a = [9, 42, 888]
b = len(a)
^Z
1 file(s) copied.
C:\junk>\python27\python
Python 2.7.1 (r271:86832, Nov 27 2010, 18:30:46) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyr...
Save Javascript objects in sessionStorage
SessionStorage and LocalStorage allows to save key/value pairs in a web browser. The value must be a string, and save js objects is not trivial.
...
How do I open a second window from the first window in WPF?
...ndows, such as window1 and window2. I have one button in window1. If I click that button, the window2 has to open. What should I do for that?
...
Error when trying vagrant up
...
It looks like you may have created a Vagrant project with just vagrant init. That will create your Vagrantfile, but it won't have a box defined.
Instead, you could try
$ vagrant init hashicorp/precise32
$ vagrant up
which uses ...