Tutorial by Examples: b

Just some methods of an object can be mocked using spy() of mockito. For example, imagine that method class requires some web service to work. public class UserManager { List<User> users; public UserManager() { user = new LinkedLisk<User>(); } ...

The following example shows a basic main GUI window with a label widget, a toolbar, and a status bar using PyQt4. import sys from PyQt4 import QtGui class App(QtGui.QApplication): def __init__(self, sys_argv): super(App, self).__init__(sys_argv) self.build_ui() ...

hashlib.new requires the name of an algorithm when you call it to produce a generator. To find out what algorithms are available in the current Python interpreter, use hashlib.algorithms_available: import hashlib hashlib.algorithms_available # ==> {'sha256', 'DSA-SHA', 'SHA512', 'SHA224', 'dsa...

An easier approach for some would be to use an existing JavaScript library. This is because it can be tricky to guarantee browser detection is correct, so it can make sense to use a working solution if one is available. One popular browser-detection library is Bowser. Usage example: if (bowser.ms...

When you are copying a string into a malloced buffer, always remember to add 1 to strlen. char *dest = malloc(strlen(src)); /* WRONG */ char *dest = malloc(strlen(src) + 1); /* RIGHT */ strcpy(dest, src); This is because strlen does not include the trailing \0 in the length. If you take the ...

The following code broadcasts the contents in buffer among all the processes belonging to the MPI_COMM_WORLD communicator (i.e. all the processes running in parallel) using the MPI_Bcast operation. int rank; int res; res = MPI_Comm_rank (MPI_COMM_WORLD, &rank); if (res != MPI_SUCCESS) { ...

Floating point types (float, double and long double) cannot precisely represent some numbers because they have finite precision and represent the values in a binary format. Just like we have repeating decimals in base 10 for fractions such as 1/3, there are fractions that cannot be represented fini...

The pickle module implements an algorithm for turning an arbitrary Python object into a series of bytes. This process is also called serializing the object. The byte stream representing the object can then be transmitted or stored, and later reconstructed to create a new object with the same charact...

Using the calendar module import calendar from datetime import date def monthdelta(date, delta): m, y = (date.month+delta) % 12, date.year + ((date.month)+delta-1) // 12 if not m: m = 12 d = min(date.day, calendar.monthrange(y, m)[1]) return date.replace(day=d,month=m, year=...

#include <stdlib.h> #include <stdio.h> int main(void) { result = EXIT_SUCCESS; char file_name[] = "outbut.bin"; char str[] = "This is a binary file example"; FILE * fp = fopen(file_name, "wb"); if (fp == NULL) /* If an erro...

To install v6.x update the packages curl -sL https://deb.nodesource.com/setup_6.x | sudo -E bash - Using the apt package manager sudo apt-get install -y nodejs

Adding a Conditional attribute from System.Diagnostics namespace to a method is a clean way to control which methods are called in your builds and which are not. #define EXAMPLE_A using System.Diagnostics; class Program { static void Main() { ExampleA(); // This method will ...

Immutability is common in functional programming and rare in object oriented programming. Create, for example, an address type with mutable state: public class Address () { public string Line1 { get; set; } public string Line2 { get; set; } public string City { get; set; } } ...

Before using your own object as key you must override hashCode() and equals() method of your object. In simple case you would have something like: class MyKey { private String name; MyKey(String name) { this.name = name; } @Override public boolean equals(Object ...

Creating a custom directive with isolated scope will separate the scope inside the directive from the outside scope, in order to prevent our directive from accidentally change the data in the parent scope and restricting it from reading private data from the parent scope. To create an isolated scop...

iex> my_string = "Lorem ipsum dolor sit amet, consectetur adipiscing elit." iex> String.slice my_string, 6..10 "ipsum"

The IEnumerable<T> interface has a single method, GetEnumerator(), which returns an IEnumerator<T>. While the yield keyword can be used to directly create an IEnumerable<T>, it can also be used in exactly the same way to create an IEnumerator<T>. The only thing that changes ...

Following is most basic expression tree that is created by lambda. Expression<Func<int, bool>> lambda = num => num == 42; To create expression trees 'by hand', one should use Expression class. Expression above would be equivalent to: ParameterExpression parameter = Expression.Pa...

5.1 JavaScript does not directly support enumerators but the functionality of an enum can be mimicked. // Prevent the enum from being changed const TestEnum = Object.freeze({ One:1, Two:2, Three:3 }); // Define a variable with a value from the enum var x = TestEnum.Two; // Prin...

Keyword for storing the Boolean values true and false. bool is an alias of System.Boolean. The default value of a bool is false. bool b; // default value is false b = true; // true b = ((5 + 2) == 6); // false For a bool to allow null values it must be initialized as a bool?. The default val...