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How do you delete a column by name in data.table?
...hod 3 (could then assign to df3,
df3[, !"foo"]
though if you were actually wanting to remove column "foo" from df3 (as opposed to just printing a view of df3 minus column "foo") you'd really want to use Method 1 instead.
(Do note that if you use a method relying on grep() or grepl(), you need ...
Why do I need to override the equals and hashCode methods in Java?
...hich will prevent your class from functioning properly in conjunction with all hash-based collections, including HashMap, HashSet, and Hashtable.
Let's try to understand it with an example of what would happen if we override equals() without overriding hashCode() and attempt to use a Map.
Say we ha...
Child inside parent with min-height: 100% not inheriting height
... on April 10, 2014
Since I'm currently working on a project for which I really need parent containers with min-height, and child elements inheriting the height of the container, I did some more research.
First: I'm not so sure anymore whether the current browser behaviour really is a bug. CSS2.1 s...
Python argparse command line flags without arguments
...a look at http://docs.python.org/dev/library/argparse.html#action (specifically store_true and store_false)
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('-w', action='store_true')
where action='store_true' implies default=False.
Conversely, you could haveaction='store_...
What is “(program)” in Chrome debugger’s profiler?
...
(program) is Chrome itself, the root of the tree calling all other code...it's there because the jump from native code to JavaScript, resource loading, etc. has to start somewhere :)
You can see examples of the treeview in the Chrome developer tool docs.
...
html select only one checkbox in a group
So how can I only allow a user to select only one checkbox?
16 Answers
16
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How to select an element by classname using jqLite?
...
Essentially, and as-noted by @kevin-b:
// find('#id')
angular.element(document.querySelector('#id'))
//find('.classname'), assumes you already have the starting elem to search from
angular.element(elem.querySelector('.classname'))...
What is the difference between Builder Design pattern and Factory Design pattern?
...
With design patterns, there usually is no "more advantageous" solution that works for all cases. It depends on what you need to implement.
From Wikipedia:
Builder focuses on constructing a
complex object step by step. Abstract
Factory emphasiz...
Handling Touch Event in UILabel and hooking it up to an IBAction
...= YES;
UITapGestureRecognizer *tapGesture =
[[UITapGestureRecognizer alloc] initWithTarget:self
action:@selector(labelTap)];
[label addGestureRecognizer:tapGesture];
The trick is to enable user interaction.
...
What is Prism for WPF?
I've come across something called Prism a lot recently. Microsoft, who run the project, describe it as
2 Answers
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