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BigInteger is in an immutable object, so you need to assign the results of any mathematical operation, to a new BigInteger instance. Addition: 10 + 10 = 20 BigInteger value1 = new BigInteger("10"); BigInteger value2 = new BigInteger("10"); BigInteger sum = value1.add(value...

It is undefined behavior to access an index that is out of bounds for an array (or standard library container for that matter, as they are all implemented using a raw array): int array[] = {1, 2, 3, 4, 5}; array[5] = 0; // Undefined behavior It is allowed to have a pointer pointing to the en...

Assuming a source file of hello_world.v and a top level module of hello_world. The code can be run using various simulators. Most simulators are compiled simulators. They require multiple steps to compile and execute. Generally the First step is to compile the Verilog design. Second step is to ...

The syntax for Java generics bounded wildcards, representing the unknown type by ? is: ? extends T represents an upper bounded wildcard. The unknown type represents a type that must be a subtype of T, or type T itself. ? super T represents a lower bounded wildcard. The unknown type repres...

DataFrame: import pandas as pd import numpy as np np.random.seed(5) df = pd.DataFrame(np.random.randint(100, size=(5, 5)), columns = list("ABCDE"), index = ["R" + str(i) for i in range(5)]) df Out[12]: A B C D E R0 99 78 61 16 73...

Extension methods can be used for writing strongly typed wrappers for dictionary-like objects. For example a cache, HttpContext.Items at cetera... public static class CacheExtensions { public static void SetUserInfo(this Cache cache, UserInfo data) => cache["UserInfo"] ...

MySQL3.19 DROP TABLE IF EXISTS MyTable; PostgreSQL8.x DROP TABLE IF EXISTS MyTable; SQL Server2005 If Exists(Select * From Information_Schema.Tables Where Table_Schema = 'dbo' And Table_Name = 'MyTable') Drop Table dbo.MyTable SQLite3.0 DROP TABLE IF EXI...

Sometimes, programmers who are new Java will use primitive types and wrappers interchangeably. This can lead to problems. Consider this example: public class MyRecord { public int a, b; public Integer c, d; } ... MyRecord record = new MyRecord(); record.a = 1; // OK ...

Use this option if you don't need an Application subclass. This is the simplest option, but this way you can't provide your own Application subclass. If an Application subclass is needed, you will have to switch to one of the other options to do so. For this option, simply specify the fully-quali...

Use this option if your project requires an Application subclass. Specify this Application subclass using the android:name property in the manifest file inside the application tag. In the Application subclass, add the attachBaseContext() method override, and in that method call MultiDex.install():...

init Called synchronously after the instance has been initialized and prior to any initial data observation. created Called synchronously after the instance is created. This occurs prior to $el setup, but after data observation, computed properties, watch/event callbacks, and methods ha...

The goal is to generate the following XML document: <FruitBasket xmlns="http://www.fruitauthority.fake"> <Fruit ID="F0001"> <FruitName>Banana</FruitName> <FruitColor>Yellow</FruitColor> </Fruit> <Fruit ID="F000...

STEP 1: Installation Before you can use Angular-UI Router you must include AngularJS itself in your project. For a detailed guide on that see this documentation. You can download Angular-UI Router either from their GitHub-Page or from NuGet, NPM, Bower respectively. After you have included the J...

Helpful when you want to grab a copy of a production database to play around with locally. mongodump --host some-mongo-host.com:1234 -d DATABASE_NAME -u DATABASE_USER -p DATABASE_PASSWORD This will create a local dump directory; within that directory you'll see a directory with your DATABASE_NAME...

Matplotlib axes are two-dimensional by default. In order to create three-dimensional plots, we need to import the Axes3D class from the mplot3d toolkit, that will enable a new kind of projection for an axes, namely '3d': import matplotlib.pyplot as plt from mpl_toolkits.mplot3d import Axes3D fi...

If you want two or more arguments to be mutually exclusive. You can use the function argparse.ArgumentParser.add_mutually_exclusive_group(). In the example below, either foo or bar can exist but not both at the same time. import argparse parser = argparse.ArgumentParser() group = parser.add_mut...

To modify an existing column in Rails with a migration, run the following command: rails g migration change_column_in_table This will create a new migration file in db/migration directory (if it doesn’t exist already), which will contain the file prefixed with timestamp and migration file name w...

In order to enable a multidex configuration you need: to change your Gradle build configuration to use a MultiDexApplication or enable the MultiDex in your Application class Gradle configuration In app/build.gradle add these parts: android { compileSdkVersion 24 buildToolsVersion ...

The dexcount plugin counts methods and class resource count after a successful build. Add the plugin in the app/build.gradle: apply plugin: 'com.android.application' buildscript { repositories { mavenCentral() // or jcenter() } dependencies { classpath 'com.ge...

A series is a one-dimension data structure. It's a bit like a supercharged array, or a dictionary. import pandas as pd s = pd.Series([10, 20, 30]) >>> s 0 10 1 20 2 30 dtype: int64 Every value in a series has an index. By default, the indices are integers, running fro...