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Using Default Arguments in a Function
...you can do what you want:
function foo($blah, $x = null, $y = null) {
if (null === $x) {
$x = "some value";
}
if (null === $y) {
$y = "some other value";
}
code here!
}
This way, you can make a call like foo('blah', null, 'non-default y value'); and have it ...
Find first element in a sequence that matches a predicate
...t element in a sequence seq that matches a predicate:
next(x for x in seq if predicate(x))
Or (itertools.ifilter on Python 2):
next(filter(predicate, seq))
It raises StopIteration if there is none.
To return None if there is no such element:
next((x for x in seq if predicate(x)), None)
O...
How to disable an input type=text?
...want to disable writing in an input field of type text using JavaScript, if possible.
The input field is populated from a database; that is why I don't want the user to modify its value.
...
Sorting a set of values [closed]
...o store the numbers as numbers rather than strings in the first place. But if not, you just need to use a key function:
>>> sorted(s, key=float)
['0.000000000', '0.009518000', '0.018384000', '0.030810999', '4.918560000', '10.277200999']
For more information, see the Sorting HOWTO in th...
Detect Android phone via Javascript / jQuery
...ndroid = ua.indexOf("android") > -1; //&& ua.indexOf("mobile");
if(isAndroid) {
// Do something!
// Redirect to Android-site?
window.location = 'http://android.davidwalsh.name';
}
PHP:
$ua = strtolower($_SERVER['HTTP_USER_AGENT']);
if(stripos($ua,'android') !== false) { // &&...
What is the difference between packaged_task and async
...
Actually the example you just gave shows the differences if you use a rather long function, such as
//! sleeps for one second and returns 1
auto sleep = [](){
std::this_thread::sleep_for(std::chrono::seconds(1));
return 1;
};
Packaged task
A packaged_task won...
How do I add a class to a given element?
...
If you're only targeting modern browsers:
Use element.classList.add to add a class:
element.classList.add("my-class");
And element.classList.remove to remove a class:
element.classList.remove("my-class");
If you need t...
What are “connecting characters” in Java identifiers?
...t i = Character.MIN_CODE_POINT; i <= Character.MAX_CODE_POINT; i++)
if (Character.isJavaIdentifierStart(i) && !Character.isAlphabetic(i))
System.out.print((char) i + " ");
}
prints
$ _ ¢ £ ¤ ¥ ؋ ৲ ৳ ৻ ૱ ௹ ฿ ៛ ‿ ⁀ ⁔ ₠ ₡ ₢ ₣ ₤ ₥ ₦ ₧ ...
Length of an integer in Python
...
If you want the length of an integer as in the number of digits in the integer, you can always convert it to string like str(133) and find its length like len(str(123)).
...
How do I exchange keys with values in a dictionary?
...
What if values are not unique? Then the keys should be a list... for example: d = {'a':3, 'b': 2, 'c': 2} {v:k for k,v in d.iteritems()} {2: 'b', 3: 'a'} should be {2: ['b','c'], 3: 'a'}
– Hanan Shteingart
...