Tutorial by Examples: le

<?php while ($condition): do_something(); endwhile; ?> <?php while ($condition): ?> <p>Do something in HTML</p> <?php endwhile; ?>

Python uses the C3 linearization algorithm to determine the order in which to resolve class attributes, including methods. This is known as the Method Resolution Order (MRO). Here's a simple example: class Foo(object): foo = 'attr foo of Foo' class Bar(object): foo = 'attr foo o...

The UITableViewDelegate is used to control how the table is displayed, and UITableViewDataSource is used to define the UITableView's data. There are two required methods and many optional ones which can be used to customize size, sections, headings, and cells in the UITableView. UITableViewDataSo...

To change the default stack order positioned elements (position property set to relative, absolute or fixed), use the z-index property. The higher the z-index, the higher up in the stacking context (on the z-axis) it is placed. Example In the example below, a z-index value of 3 puts green on to...

Sometimes it's not a good practice expose an internal collection since it can lead to a malicious code vulnerability due to it's mutable characteristic. In order to provide "read-only" collections java provides its unmodifiable versions. An unmodifiable collection is often a copy of a mod...

If you are using the default bash prompt on Linux, you should see the name of the virtual environment at the start of your prompt. (my-project-env) user@hostname:~$ which python /home/user/my-project-env/bin/python

By default, the various Collection types are not thread-safe. However, it's fairly easy to make a collection thread-safe. List<String> threadSafeList = Collections.synchronizedList(new ArrayList<String>()); Set<String> threadSafeSet = Collections.synchronizedSet(new HashSet<S...

Now that the router is configured and our app knows how to handle the routes, we need to show the actual components that we configured. To do so, configure your HTML template/file for your top-level (app) component like so: //app.ts import {Component} from '@angular/core'; import {Router, ROUT...

The @import CSS at-rule is used to import style rules from other style sheets. These rules must precede all other types of rules, except @charset rules; as it is not a nested statement, @import cannot be used inside conditional group at-rules. @import. How to use @import You can use @import rule ...

To generate a controller (for example Posts), navigate to your project directory from a command line or terminal, and run: $ rails generate controller Posts You can shorten this code by replacing generate with g, for example: $ rails g controller Posts If you open up the newly generated app/...

docker rm can be used to remove a specific containers like this: docker rm <container name or id> To remove all containers you can use this expression: docker rm $(docker ps -qa) By default docker will not delete a container that is running. Any container that is running will produce a...

This code can be added to any event like a listener, button, etc. A blocking JDialog will appear and will remain until the process is complete. final JDialog loading = new JDialog(parentComponent); JPanel p1 = new JPanel(new BorderLayout()); p1.add(new JLabel("Please wait..."), BorderLa...

You can use the clearRect method to clear any rectangular section of the canvas. // Clear the entire canvas ctx.clearRect(0, 0, canvas.width, canvas.height); Note: clearRect is dependent on the transformation matrix. To deal with this, it's possible to reset the transformation matrix befor...

Files opened in a non-binary mode (e.g. 'r' or 'w') deal with strings. The deafult encoding is 'utf8'. open(fn, mode='r') # opens file for reading in utf8 open(fn, mode='r', encoding='utf16') # opens file for reading utf16 # ERROR: cannot write bytes when a string is expecte...

Create a ModelForm from an existing Model class, by subclassing ModelForm: from django import forms class OrderForm(forms.ModelForm): class Meta: model = Order fields = ['item', 'order_date', 'customer', 'status']

In Go, an interface is just a set of methods. We use an interface to specify a behavior of a given object. type Painter interface { Paint() } The implementing type need not declare that it is implementing the interface. It is enough to define methods of the same signature. type Rembrandt ...

The jQuery UI framework helps to extend and increase the User Interface controls for jQuery JavaScript library. When you wish to use jQuery UI, you will need to add these libraries to your HTML. A quick way to start is using the Content Delivery Network available code sources: jQuery Libraries ht...

You can create a tuple and use a switch like so: var str: String? = "hi" var x: Int? = 5 switch (str, x) { case (.Some,.Some): print("Both have values") case (.Some, nil): print("String has a value") case (nil, .Some): print("Int has a value&...

This example of the Sortable using a Placeholder is common usage. Sortable is applied to a group of DOM elements, allowing the user to move items around in the list via Drag'n Drop style actions. <!doctype html> <html lang="en"> <head> <meta charset="utf-8&q...

While the math.sqrt function is provided for the specific case of square roots, it's often convenient to use the exponentiation operator (**) with fractional exponents to perform nth-root operations, like cube roots. The inverse of an exponentiation is exponentiation by the exponent's reciprocal. S...