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Code Complete 2

High Quality Routines

Rountines includes functions(which has return value) and procedure(which has no return)

creating routine

• the reason for creating routine

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// refer to https://github.com/ardalis/GuardClauses/tree/main

public interface IGuardClause { }
  
public class Guard : IGuardClause
{
  private Guard() { }
  
  public static IGuardClause Against { get; } = new Guard();
}

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// https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-8.0/ranges

#region Indexable Example
//System.Index
// use '^' operator: means read from end = true
// '^' operator requires type is countable and have indexer:

interface IIndexable<T>{
    public int Length { get; } // need public property 'Length', which has get access 
    public T this[int index] { get; } // need public indexer, which takes a single int as the argument.

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/* 
 * just for learning 
 * key concept, LinkedList
 * refer https://blog.csdn.net/qq_16587307/article/details/104301877
 * refer https://medium.com/@bonnotguillaume/software-architecture-the-pipeline-design-pattern-from-zero-to-hero-b5c43d8a4e60
 */

namespace pipeline
{
    public class Program

zhangr4

A Summary of how to use httpClient in C#

httpClient class

Normal Use

httpClient class

Factory Pattern

why use HttpClientFactory

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 Console.WriteLine();
//  <-- Keep this information secure! -->
Console.WriteLine("UserName: {0}", Environment.UserName);

//this one can get domain and user name
string userName = System.Security.Principal.WindowsIdentity.GetCurrent().Name;
Console.WriteLine();
Console.WriteLine(userName);

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# get internal ip address
ipconfig

# get external ip address
Invoke-WebRequest ifconfig.me

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import java.util.Stack;

class Program {
    public static void main(String[] args) {
        
        for(int i = 0; i <= 10; i++) {
            System.out.print(fibonacci(i) + " ");
        }
        System.out.println();
        for(int i = 0; i <= 10; i++) {

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public class quickSort {
    
    public static void main(String[] args) {
        int[] test = new int[]{5,1,1,2,0,0};        
        quickSortArr(test, 0, test.length-1);
        printArr(test);

    }

    public static void printArr(int[] arr) {

zhangr4

import java.util.function.Function;
import java.util.function.Predicate;
import java.util.regex.Pattern;
import java.util.stream.Stream;
import java.util.Arrays;

/* raw problem and better solution: 
 https://stackoverflow.com/questions/57836937/call-custom-static-functions-from-filter-and-map-in-java-8-stream
*/
class Solution {