Tutorial by Examples: io

The Problem The abstract equality and inequality operators (== and !=) convert their operands if the operand types do not match. This type coercion is a common source of confusion about the results of these operators, in particular, these operators aren't always transitive as one would expect. &...

InterruptedException is a confusing beast - it shows up in seemingly innocuous methods like Thread.sleep(), but handling it incorrectly leads to hard-to-manage code that behaves poorly in concurrent environments. At its most basic, if an InterruptedException is caught it means someone, somewhere, c...

QML comes with newer Version of the cross-platform application framework Qt. You can find the newest Version of Qt in the Downloads section. To create a new QML Project in the Qt Creator IDE, select "File -> New ..." and under "Applications" select "Qt Quick-Application...

3.0 Check if a string consists in exactly 8 digits: $ date=20150624 $ [[ $date =~ ^[0-9]{8}$ ]] && echo "yes" || echo "no" yes $ date=hello $ [[ $date =~ ^[0-9]{8}$ ]] && echo "yes" || echo "no" no

If you want to get the versioned project's data, but you don't need any of the version control capabilities offered by Subversion, you could run svn export <URL> command. Here is an example: $ svn export https://svn.example.com/svn/MyRepo/MyProject/trunk As a result, you will get the proje...

Binaries Lua binaries are provided by most GNU/Linux distributions as a package. For example, on Debian, Ubuntu, and their derivatives it can be acquired by executing this: sudo apt-get install lua50 sudo apt-get install lua51 sudo apt-get install lua52 There are some semi-of...

Evaluates its first operand, and, if the resulting value is not equal to zero, evaluates its second operand. Otherwise, it evaluates its third operand, as shown in the following example: a = b ? c : d; is equivalent to: if (b) a = c; else a = d; This pseudo-code represents it : c...

In order to get const char* access to the data of a std::string you can use the string's c_str() member function. Keep in mind that the pointer is only valid as long as the std::string object is within scope and remains unchanged, that means that only const methods may be called on the object. C++1...

The lambda keyword creates an inline function that contains a single expression. The value of this expression is what the function returns when invoked. Consider the function: def greeting(): return "Hello" which, when called as: print(greeting()) prints: Hello This can ...

Before publishing a package you have to version it. npm supports semantic versioning, this means there are patch, minor and major releases. For example, if your package is at version 1.2.3 to change version you have to: patch release: npm version patch => 1.2.4 minor release: npm version min...

This demonstrates a filter on a for-loop, and the use of yield to create a 'sequence comprehension': for ( x <- 1 to 10 if x % 2 == 0) yield x The output for this is: scala.collection.immutable.IndexedSeq[Int] = Vector(2, 4, 6, 8, 10) A for comprehension is useful when you need to crea...

Go is a statically typed language, meaning you generally have to declare the type of the variables you are using. // Basic variable declaration. Declares a variable of type specified on the right. // The variable is initialized to the zero value of the respective type. var x int var s string va...

Using the Java-SDK 3.0.1 CountDownLatch lock = new CountDownLatch(1); SpeechToText service = new SpeechToText(); service.setUsernameAndPassword("<username>", "<password>"); FileInputStream audio = new FileInputStream("filename.wav"); RecognizeOpti...

This example shows how to use the IBM Watson Speech to Text service to recognize the type of an audio file and produce a transcription of the spoken text in that file. This example requires Speech to Text service credentials and Node.js Install the npm module for the Watson Developer Cloud N...

The first operand must be a function pointer (a function designator is also acceptable because it will be converted to a pointer to the function), identifying the function to call, and all other operands, if any, are collectively known as the function call's arguments. Evaluates into the return valu...

The X-macro approach can be generalized a bit by making the name of the "X" macro an argument of the master macro. This has the advantages of helping to avoid macro name collisions and of allowing use of a general-purpose macro as the "X" macro. As always with X macros, the mas...

Node.js package configurations are contained in a file called package.json that you can find at the root of each project. You can setup a brand new configuration file by calling: npm init That will try to read the current working directory for Git repository information (if it exists) and enviro...

HTML input validation is done automatically by the browser based on special attributes on the input element. It could partially or completely replace JavaScript input validation. This kind of validation can be circumvented by the user via specially crafted HTTP requests, so it does not replace serve...

A bit counter-intuitive to the way most other languages' standard I/O libraries do it, Haskell's isEOF does not require you to perform a read operation before checking for an EOF condition; the runtime will do it for you. import System.IO( isEOF ) eofTest :: Int -> IO () eofTest line = do ...

In Google Chrome, you can pause execution without needing to place breakpoints. Pause on Exception: While this button is toggled on, if your program hits an unhandled exception, the program will pause as if it had hit a breakpoint. The button can be found near Execution Controls and is useful for ...