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Why is lazy evaluation useful?
...epending on the sequence of conditional expressions, only a subset may actually be used. In a language like C, all three values would be computed anyway; but in Haskell, only the necessary values are computed.
It also allows for cool stuff like infinite lists. I can't have an infinite list in a lan...
Difference between .on('click') vs .click()
....on over .click because the former can use less memory and work for dynamically added elements.
Consider the following html:
<html>
<button id="add">Add new</button>
<div id="container">
<button class="alert">alert!</button>
</div>
<...
What is better, adjacency lists or adjacency matrices for graph problems in C++?
...e of a specific edge
between any two nodes O(1)
It is slow to iterate over all edges
It is slow to add/delete a node; a complex operation O(n^2)
It is fast to add a new edge O(1)
Adjacency List
Memory usage depends on the number of edges (not number of nodes),
which might save a lot of memor...
Android adding simple animations while setvisibility(view.Gone)
...yout like changing view visibility or view positions android will automatically create fade/transition animations. To use that set
android:animateLayoutChanges="true"
on the root node in your layout.
Your second option would be to manually add animations. For this I suggest you use the new anim...
Execute command on all files in a directory
...rovide the code to do the following:
Assume there is a directory of files, all of which need to be run through a program. The program outputs the results to standard out. I need a script that will go into a directory, execute the command on each file, and concat the output into one big output file.
...
SQL UPDATE all values in a field with appended string CONCAT not working
...
That's pretty much all you need:
mysql> select * from t;
+------+-------+
| id | data |
+------+-------+
| 1 | max |
| 2 | linda |
| 3 | sam |
| 4 | henry |
+------+-------+
4 rows in set (0.02 sec)
mysql> update t se...
Can I disable a CSS :hover effect via JavaScript?
... and CSS a little bit, it saves you having to reset every CSS property manually via JavaScript.
HTML
<body class="nojQuery">
CSS
/* Limit the hover styles in your CSS so that they only apply when the nojQuery
class is present */
body.nojQuery ul#mainFilter a:hover {
/* CSS-only hove...
How to call an external command?
How do you call an external command (as if I'd typed it at the Unix shell or Windows command prompt) from within a Python script?
...
Checkout another branch when there are uncommitted changes on the current branch
...st of the time when I try to checkout another existing branch, Git doesn't allow me if I have some uncommitted changes on the current branch. So I'll have to commit or stash those changes first.
...
Python - List of unique dictionaries
...
If you need all values considered and not just the ID you can use list({str(i):i for i in L}.values()) Here we use str(i) to create a unique string that represents the dictionary which is used to filter the duplicates.
...