Since you’re referring to instance variables, I’m assuming that you’re working in an object-oriented language. To some degree, when to use instance variables, how to define their scope, and when to use local variables is subjective, but there are a couple of rules of thumb you can follow whenever creating your classes. Instance variables are … Read more
As to the cause, the <f:attribute> is specific to the component itself (populated during view build time), not to the iterated row (populated during view render time). There are several ways to achieve the requirement. If your servletcontainer supports a minimum of Servlet 3.0 / EL 2.2, then just pass it as an argument of … Read more
urls.py: #… url(r’element/update/(?P<pk>\d+)/$’, ‘element.views.element_update’, name=”element_update”), views.py: from django.shortcuts import redirect from .models import Element def element_info(request): # … element = Element.object.get(pk=1) return redirect(‘element_update’, pk=element.id) def element_update(request, pk) # …
If you don’t need anything fancy like delaying the evaluation of the function name or its arguments, you don’t need eval: function x() { echo “Hello world”; } function around() { echo before; $1; echo after; } around x does what you want. You can even pass the function and its arguments this way: function … Read more
In Effective Java, Chapter 7 (Methods), Item 40 (Design method signatures carefully), Bloch writes: There are three techniques for shortening overly long parameter lists: break the method into multiple methods, each which require only a subset of the parameters create helper classes to hold group of parameters (typically static member classes) adapt the Builder pattern … Read more
e is the short var reference for event object which will be passed to event handlers. The event object essentially has lot of interesting methods and properties that can be used in the event handlers. In the example you have posted is a click handler which is a MouseEvent $(<element selector>).click(function(e) { // does something … Read more
When passing an array as a parameter, this void arraytest(int a[]) means exactly the same as void arraytest(int *a) so you are modifying the values in main. For historical reasons, arrays are not first class citizens and cannot be passed by value.
With Bash version 4.3 and above, you can make use of a nameref so that the caller can pass in the array name and the callee can use a nameref to populate the named array, indirectly. #!/usr/bin/env bash create_array() { local -n arr=$1 # use nameref for indirection arr=(one “two three” four) } use_array() { … Read more
Timer.Elapsed expects method of specific signature (with arguments object and EventArgs). If you want to use your PlayMusicEvent method with additional argument evaluated during event registration, you can use lambda expression as an adapter: myTimer.Elapsed += new ElapsedEventHandler((sender, e) => PlayMusicEvent(sender, e, musicNote)); Edit: you can also use shorter version: myTimer.Elapsed += (sender, e) => … Read more
What I have done in this case is pass an array, where the key is the parameter name, and the value is the value. $optional = array( “param” => $param1, “param2” => $param2 ); function func($required, $requiredTwo, $optional) { if(isset($optional[“param2”])) { doWork(); } }