Tutorial by Examples: c

Exceptions represent programmer-level bugs like trying to access an array element that doesn’t exist. Errors are user-level issues like trying load a file that doesn’t exist. Because errors are expected during the normal execution of a program. Example: NSArray *inventory = @[@"Sam"...

Before we download and install Composer, we need to make sure our server has all dependencies installed. First, update the package manager cache by running: sudo apt-get update Now, let's install the dependencies. We'll need curl in order to download Composer and php5-cli for installing and run...

Using raw values directly from the accelerometer sensor to move or rotate a GameObject can cause problems such as jerky movements or vibrations. It is recommended to smooth out the values before using them. In fact, values from the accelerometer sensor should always be smoothed out before use. This ...

If a bean is defined with singleton scope, there will only be one single object instance initialized in the Spring container. All requests to this bean will return the same shared instance. This is the default scope when defining a bean. Given the following MyBean class: public class MyBean { ...

A prototype-scoped bean is not pre-created on Spring container startup. Instead, a new fresh instance will be created every time a request to retrieve this bean is sent to the container. This scope is recommended for stateful objects, since its state won't be shared by other components. In order to...

First make utility class or use this method in class needed public class UIUtils { public static BitmapImageViewTarget getRoundedImageTarget(@NonNull final Context context, @NonNull final ImageView imageView, final float radius) { retur...

The following examples will use this class hierarchy: struct A { int m; }; struct B : A {}; struct C : B {}; The conversion from derived class type to base class type is preferred to user-defined conversions. This applies when passing by value or by reference, as well as when converting pointe...

To create a simple variable and assign it to a value or string use the SET command: SET var=10 Here, the code declares a new variable var with a value of 10. By default all variables are stored internally as strings; this means that the value 10 is no different to foo1234 or Hello, World! Notes...

Warning: The functions atoi, atol, atoll and atof are inherently unsafe, because: If the value of the result cannot be represented, the behavior is undefined. (7.20.1p1) #include <stdio.h> #include <stdlib.h> int main(int argc, char** argv) { int val; if (argc < 2) ...

The contents of files and network messages may represent encoded characters. They often need to be converted to unicode for proper display. In Python 2, you may need to convert str data to Unicode characters. The default ('', "", etc.) is an ASCII string, with any values outside of ASCII ...

This command: :s/foo/bar/g substitutes each occurrence of foo with bar on the current line. fool around with a foodie becomes barl around with a bardie If you leave off the last /g, it will only replace the first occurence on the line. For example, :s/foo/bar On the previous line wou...

Add 'exception' as a suffix Custom exception names should be suffixed with "-Exception". Below are correctly named exceptions: public class MyCustomException : Exception public class FooException : Exception

map Overview A key sequence can be re-mapped to another key sequence using one of the map variants. As an example, the following typical map will exit Insert mode when you press jk in quick sequence: :inoremap jk <Esc> map Operator There are multiple variants of :map for different modes...

VBA is compiled in run-time, which has a huge negative impact on it's performance, everything built-in will be faster, try to use them. As an example I'm comparing SUM and COUNTIF functions, but you can use if for anything you can solve with WorkSheetFunctions. A first attempt for those would be t...

This example shows how to mock out a function call that is irrelevant to our unit test, and then use the defer statement to re-assign the mocked function call back to its original function. var validate = validateDTD // ParseXML parses b for XML elements and values, and returns them as a map of ...

Although available, defining a class from scratch is not recommended in modern Perl. Use one of helper OO systems which provide more features and convenience. Among these systems are: Moose - inspired by Perl 6 OO design Class::Accessor - a lightweight alternative to Moose Class::Tiny...

In this example we create a goroutine (a function running in a separate thread) that accepts a chan parameter, and simply loops, sending information into the channel each time. In the main we have a for loop and a select. The select will block processing until one of the case statements becomes tru...

So here, I have removed the for loops, and made a timeout by adding a second case to the select that returns after 3 seconds. Because the select just waits until ANY case is true, the second case fires, and then our script ends, and chatter() never even gets a chance to finish. // Use of the select...

Subroutine arguments in Perl are passed by reference, unless they are in the signature. This means that the members of the @_ array inside the sub are just aliases to the actual arguments. In the following example, $text in the main program is left modified after the subroutine call because $_[0] in...

1.7+ Timing out an HTTP request with a context can be accomplished with only the standard library (not the subrepos) in 1.7+: import ( "context" "net/http" "time" ) req, err := http.NewRequest("GET", `https://example.net`, nil) ctx, _ := ...