Tutorial by Examples: le

If no ordering function is passed, std::sort will order the elements by calling operator< on pairs of elements, which must return a type contextually convertible to bool (or just bool). Basic types (integers, floats, pointers etc) have already build in comparison operators. We can overload this ...

To add a new unique column email to users, run the following command: rails generate migration AddEmailToUsers email:string:uniq This will create the following migration: class AddEmailToUsers < ActiveRecord::Migration[5.0] def change add_column :users, :email, :string add_index...

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...

Model with ForeignKey We will work with these models : from django.db import models class Book(models.Model): name= models.CharField(max_length=50) author = models.ForeignKey(Author) class Author(models.Model): name = models.CharField(max_length=50) Suppose we often (always) access ...

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 ...

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...

Alamofire.request(.GET, "https://httpbin.org/get", parameters: ["foo": "bar"]) .validate() .response { request, response, data, error in print(request) print(response) print(data) print(error) }

Alamofire.request(.GET, "https://httpbin.org/get") .validate() .responseString { response in print("Response String: \(response.result.value)") } .responseJSON { response in print("Response JSON: \(response.result.value)") ...

public static Unsafe getUnsafe() { try { Field unsafe = Unsafe.class.getDeclaredField("theUnsafe"); unsafe.setAccessible(true); return (Unsafe) unsafe.get(null); } catch (IllegalAccessException e) { // Handle } catch (IllegalArgumentExcept...

Drop Table MyTable;

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 ...

When you do a groupby you can select either a single column or a list of columns: In [11]: df = pd.DataFrame([[1, 1, 2], [1, 2, 3], [2, 3, 4]], columns=["A", "B", "C"]) In [12]: df Out[12]: A B C 0 1 1 2 1 1 2 3 2 2 3 4 In [13]: g = df.groupby(...

SELECT s.name + '.' + t.NAME AS TableName, SUM(a.used_pages)*8 AS 'TableSizeKB' --a page in SQL Server is 8kb FROM sys.tables t JOIN sys.schemas s on t.schema_id = s.schema_id LEFT JOIN sys.indexes i ON t.OBJECT_ID = i.object_id LEFT JOIN sys.partitions p ON i.object_id = ...

Caller info attributes can be used to pass down information about the invoker to the invoked method. The declaration looks like this: using System.Runtime.CompilerServices; public void LogException(Exception ex, [CallerMemberName]string callerMemberName = "", ...

Boolean(...) will convert any data type into either true or false. Boolean("true") === true Boolean("false") === true Boolean(-1) === true Boolean(1) === true Boolean(0) === false Boolean("") === false Boolean("1") === true Boolean("0") === t...

XML elements often nest, have data in attributes and/or as character data. The way to capture this data is by using ,attr and ,chardata respectively for those cases. var doc = ` <parent> <child1 attr1="attribute one"/> <child2>and some cdata</child2> </p...

You can mix normal parameters and parameter arrays: public class LotteryTicket : IEnumerable{ public int[] LuckyNumbers; public string UserName; public void Add(string userName, params int[] luckyNumbers){ UserName = userName; Lottery = luckyNumbers; } } ...

/** * Created by Alex Sullivan on 7/21/16. */ public class Foo implements Parcelable { private final int myFirstVariable; private final String mySecondVariable; private final long myThirdVariable; public Foo(int myFirstVariable, String mySecondVariable, long myThirdVariab...

Inline style You can manipulate the inline CSS style of an HTML element by simply reading or editing its style property. Assume the following element: <div id="element_id" style="color:blue;width:200px;">abc</div> With this JavaScript applied: var element = doc...

import "reflect" value := reflect.ValueOf(4) // Interface returns an interface{}-typed value, which can be type-asserted value.Interface().(int) // 4 // Type gets the reflect.Type, which contains runtime type information about // this value value.Type().Name() // int value.SetInt(5)...