Tutorial by Examples: ch

For the character entity character(len=5), parameter :: greeting = "Hello" a substring may be referenced with the syntax greeting(2:4) ! "ell" To access a single letter it isn't sufficient to write greeting(1) ! This isn't the letter "H" but greeting(1:...

Asynchronously var fs = require('fs'); fs.stat('path/to/file', function(err) { if (!err) { console.log('file or directory exists'); } else if (err.code === 'ENOENT') { console.log('file or directory does not exist'); } }); Synchronously here, we must wr...

You've made a stash and wish to checkout only some of the files in that stash. git checkout stash@{0} -- myfile.txt

Watchers needed for watch some value and detect that this value is changed. After call $watch() or $watchCollection new watcher add to internal watcher collection in current scope. So, what is watcher? Watcher is a simple function, which is called on every digest cycle, and returns some value. An...

foreach is a construct, which enables you to iterate over arrays and objects easily. $array = [1, 2, 3]; foreach ($array as $value) { echo $value; } Outputs: 123. To use foreach loop with an object, it has to implement Iterator interface. When you iterate over associative arrays: $arra...

Assuming we want to modify bit n of an integer primitive, i (byte, short, char, int, or long): (i & 1 << n) != 0 // checks bit 'n' i |= 1 << n; // sets bit 'n' to 1 i &= ~(1 << n); // sets bit 'n' to 0 i ^= 1 << n; // toggles the value of bit 'n' Us...

C++11 std::string supports iterators, and so you can use a ranged based loop to iterate through each character: std::string str = "Hello World!"; for (auto c : str) std::cout << c; You can use a "traditional" for loop to loop through every character: std::stri...

It should be noted that Fetch does not support progress callbacks. See: https://github.com/github/fetch/issues/89. The alternative is to use XMLHttpRequest https://developer.mozilla.org/en-US/docs/Web/Events/progress. fetch('https://mywebsite.com/mydata.json').then(json => console.log(json)); ...

While it's often tempting to catch every Exception: try: very_difficult_function() except Exception: # log / try to reconnect / exit gratiously finally: print "The END" # it runs no matter what execute. Or even everything (that includes BaseException and all its c...

There are a few ways to catch multiple exceptions. The first is by creating a tuple of the exception types you wish to catch and handle in the same manner. This example will cause the code to ignore KeyError and AttributeError exceptions. try: d = {} a = d[1] b = d.non_existing_fiel...

If you don't know which options you should use, you may be interested in the :options command. This will open a split with all Vim options listed and with their current value displayed. There are 26 sections to display all options you can try. e.g. 4 displaying text scroll number of lines t...

During development, when certain code paths must be prevented from the reach of control flow, you may use assert(0) to indicate that such a condition is erroneous: switch (color) { case COLOR_RED: case COLOR_GREEN: case COLOR_BLUE: break; default: assert(0); ...

Log into a running container A user can enter a running container in a new interactive bash shell with exec command. Say a container is called jovial_morse then you can get an interactive, pseudo-TTY bash shell by running: docker exec -it jovial_morse bash Log into a running container with a s...

The two possible ways of issuing a context.become (replacing or adding the new behavior) are offered separately to enable a clutter-free notation of nested receives: val a = actor(new Act { become { // this will replace the initial (empty) behavior case "info" ⇒ sender() ! "A...

Open Control Panel -> Programs and Features, choose the Visual Studio 2015 item, and then choose the Change button. In the setup wizard for Visual Studio, choose the Modify button. In the list of optional features to install, select the HTML/JavaScript (Apache Cordova) checkbox, c...

In Visual Studio, choose Tools->Extensions and Updates. In the Updates tab of the Extensions and Updates dialog box, choose Product Updates. If an update for Visual Studio Tools for Apache appears, select it, and then choose the Update button.

C# statements executes in either checked or unchecked context. In a checked context, arithmetic overflow raises an exception. In an unchecked context, arithmetic overflow is ignored and the result is truncated. short m = 32767; short n = 32767; int result1 = checked((short)(m + n)); //will ...

A good example of a feature that request platform specific code is when you want to implement text-to-speech (tts). This example assumes that you are working with shared code in a PCL library. A schematic overview of our solution would look like the image underneath. In our shared code we define...

[\+\-]?\d+(\.\d*)? This will match any signed float, if you don't want signs or are parsing an equation remove [\+\-]? so you have \d+(\.\d+)? Explanation: \d+ matches any integer ()? means the contents of the parentheses are optional but always have to appear together '\.' matches '.', we ...

Let's say that we want to have an alternative greeting that is accessible through a different URL. We might create a new function or even a new controller for that, but a best practice is to optimize what we already have, to make it work at it's best! To do this, we'll keep the same view as in the ...