Usually, a Python dictionary throws a KeyError if you try to get an item with a key that is not currently in the dictionary. The defaultdict in contrast will simply create any items that you try to access (provided of course they do not exist yet). To create such a “default” item, it calls the … Read more
For future reference, I have to include the HTML5 way to do this. <input name=”Email” type=”text” id=”Email” value=”[email protected]” placeholder=”What’s your programming question ? be specific.” /> If you have a HTML5 doctype and a HTML5-compliant browser, this will work. However, many browsers do not currently support this, so at least Internet Explorer users will not … Read more
You can use application/octet-stream for unknown types. RFC 2046 states in section 4.5.1: The “octet-stream” subtype is used to indicate that a body contains arbitrary binary data.
Your code (simplified): struct X { int mem; void f(int param = mem); //ERROR }; You want to use a non-static member data as default value for a parameter of a member function. The first question which comes to mind is this : which specific instance of the class the default value mem belongs to? … Read more
This should be faster for larger arrays. For smaller arrays any method will do. $existingKeys = array_keys($array); //you can use any value instead of null $newKeys = array_fill_keys(range(min($existingKeys), max($existingKeys)), null); $array += $newKeys; //optional, probably not needed ksort($array);
The default value for a Boolean (object) is null. The default value for a boolean (primitive) is false.
Yes you can use array_merge in this case: $a = array(‘a’ => ‘some value’, ‘b’ => ‘some value’, ‘c’ => ‘some value’); $b = array(‘a’ => ‘another value’, ‘d’ => ‘another value’, ‘e’ => ‘another value’, ‘f’ => ‘another value’); $c = array(‘b’ => ‘some more value’, ‘x’ => ‘some more value’, ‘y’ => ‘some … Read more
This is defined in the standard, yes. map is performing “default initialization” in this case. As you say, for class types, that calls a no-arguments constructor. For built-in types, in the ’98 standard, see section 8.5, “Initializers”: To default-initialize an object of type T means: if T is a non-POD … if T is an … Read more
It’s still not possible.
The scope is as you would expect. The perhaps surprising thing is that the default value is only calculated once and reused, so each time you call the function you get the same list, not a new list initialized to []. The list is stored in f.__defaults__ (or f.func_defaults in Python 2.) def f(a, L=[]): … Read more