Csharp/C Sharp by API/System.Collections.Generic/List

extends List

<source lang="csharp"> using System; using System.Collections.Generic; using System.Text; public static class VectorDelegates {

   public static int Compare(Vector x, Vector y) {
       if (x.R > y.R) {
           return 1;
       } else if (x.R < y.R) {
           return -1;
       }
       return 0;
   }
   public static bool TopRightQuadrant(Vector target) {
       if (target.Theta >= 0.0 && target.Theta <= 90.0) {
           return true;
       } else {
           return false;
       }
   }

} public class Vectors : List<Vector> {

   public Vectors() {
   }
   public Vectors(IEnumerable<Vector> initialItems) {
       foreach (Vector vector in initialItems) {
           Add(vector);
       }
   }
   public string Sum() {
       StringBuilder sb = new StringBuilder();
       Vector currentPoint = new Vector(0.0, 0.0);
       sb.Append("origin");
       foreach (Vector vector in this) {
           sb.AppendFormat(" + {0}", vector);
           currentPoint += vector;
       }
       sb.AppendFormat(" = {0}", currentPoint);
       return sb.ToString();
   }

} public class Vector {

   public double? R = null;
   public double? Theta = null;
   public double? ThetaRadians {
       get {
           return (Theta * Math.PI / 180.0);
       }
   }
   public Vector(double? r, double? theta) {
       if (r < 0) {
           r = -r;
           theta += 180;
       }
       theta = theta % 360;
       R = r;
       Theta = theta;
   }
   public static Vector operator +(Vector op1, Vector op2) {
       try {
           double newX = op1.R.Value * Math.Sin(op1.ThetaRadians.Value)
              + op2.R.Value * Math.Sin(op2.ThetaRadians.Value);
           double newY = op1.R.Value * Math.Cos(op1.ThetaRadians.Value)
              + op2.R.Value * Math.Cos(op2.ThetaRadians.Value);
           double newR = Math.Sqrt(newX * newX + newY * newY);
           double newTheta = Math.Atan2(newX, newY) * 180.0 / Math.PI;
           return new Vector(newR, newTheta);
       } catch {
           return new Vector(null, null);
       }
   }
   public static Vector operator -(Vector op1) {
       return new Vector(-op1.R, op1.Theta);
   }
   public static Vector operator -(Vector op1, Vector op2) {
       return op1 + (-op2);
   }
   public override string ToString() {
       string rString = R.HasValue ? R.ToString() : "null";
       string thetaString = Theta.HasValue ? Theta.ToString() : "null";
       return string.Format("({0}, {1})", rString, thetaString);
   }

} class Program {

   static void Main(string[] args) {
       Vectors route = new Vectors();
       route.Add(new Vector(2.0, 90.0));
       route.Add(new Vector(1.0, 180.0));
       route.Add(new Vector(0.5, 45.0));
       route.Add(new Vector(2.5, 315.0));
       Console.WriteLine(route.Sum());
       Comparison<Vector> sorter = new Comparison<Vector>(VectorDelegates.rupare);
       route.Sort(sorter);
       Console.WriteLine(route.Sum());
       Predicate<Vector> searcher = new Predicate<Vector>(VectorDelegates.TopRightQuadrant);
       Vectors topRightQuadrantRoute = new Vectors(route.FindAll(searcher));
       Console.WriteLine(topRightQuadrantRoute.Sum());
   }

}

 </source>

List.Add

<source lang="csharp"> using System; using System.Collections.Generic; public class MainClass {

   static void Main() {
       List<int> intList = new List<int>();
       intList.Add( 1 );
       intList.Add( 2 );
       intList.Add( 3 );
       intList.Add( 4 );
       foreach( int n in CreateReverseIterator(intList) ) {
           Console.WriteLine( n );
       }
   }
   static IEnumerable<T> CreateReverseIterator<T>( IList<T> list ) {
       int count = list.Count;
       for( int i = count-1; i >= 0; --i ) {
           yield return list[i];
       }
   }

}

 </source>

List.AsReadOnly()

<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Text; public class MainClass {

   public static void Main()
   {
       List<int> intList = new List<int>(new int[] { 3, 5, 15, 1003, 25 });
       ReadOnlyCollection<int> roList = intList.AsReadOnly();
   }

}

 </source>

List.Capacity

<source lang="csharp"> using System; using System.Collections.Generic;

class MainClass {

 public static void Main() {  
   List<char> lst = new List<char>();  
     
   Console.WriteLine("Initial number of elements: " +  
                      lst.Count);  
 
   Console.WriteLine();  
 
   Console.WriteLine("Adding 6 elements");  
   lst.Add("C");  
   lst.Add("A");  
   lst.Add("E");  
   lst.Add("B");  
   lst.Add("D");  
   lst.Add("F");  
 
   Console.WriteLine("Number of elements: " +  
                      lst.Count);  
 
    Console.WriteLine("Adding 20 more elements");  
   // Add enough elements to force lst to grow.  
   for(int i=0; i < 20; i++)  
     lst.Add((char)("a" + i));  
   Console.WriteLine("Current capacity: " +  
                      lst.Capacity);  
   Console.WriteLine("Number of elements after adding 20: " +  
                      lst.Count);  
   Console.Write("Contents: ");  
   foreach(char c in lst)  
     Console.Write(c + " ");  
   Console.WriteLine("\n");  
 }

}

 </source>

List.ConvertAll

<source lang="csharp">

using System; using System.Collections; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Text; public class MainClass {

   public static void Main()
   {
       List<string> stringList1 = new List<string>(new string[] { "99", "182", "15" });
       List<int> intList1 = stringList1.ConvertAll<int>(Convert.ToInt32);
   }

}

 </source>

List.Count

<source lang="csharp">

using System; using System.Collections.Generic;

class MainClass {

 public static void Main() {  
   List<char> lst = new List<char>();  
     
   Console.WriteLine("Initial number of elements: " +  
                      lst.Count);  
 
   Console.WriteLine();  
 
   Console.WriteLine("Adding 6 elements");  
   lst.Add("C");  
   lst.Add("A");  
   lst.Add("E");  
   lst.Add("B");  
   lst.Add("D");  
   lst.Add("F");  
 
   Console.WriteLine("Number of elements: " +  
                      lst.Count);  
 
   Console.Write("Current contents: ");  
   for(int i=0; i < lst.Count; i++)  
     Console.Write(lst[i] + " ");  
   Console.WriteLine("\n");  
 }

}

 </source>

List.ForEach

<source lang="csharp"> using System; using System.Collections; using System.Collections.Generic; using System.Collections.ObjectModel; using System.Text; public class MainClass {

   public static void Main()
   {
       List<int> intList = new List<int>(new int[] { 3, 5, 15, 1003, 25 });
       
       intList.ForEach(delegate(int x) { Console.WriteLine(x); });
   }

}

 </source>

List.Remove()

<source lang="csharp"> using System; using System.Collections.Generic;

class MainClass {

 public static void Main() {  
   List<char> lst = new List<char>();  
     
   Console.WriteLine("Initial number of elements: " +  
                      lst.Count);  
 
   Console.WriteLine();  
 
   Console.WriteLine("Adding 6 elements");  
   lst.Add("C");  
   lst.Add("A");  
   lst.Add("E");  
   lst.Add("B");  
   lst.Add("D");  
   lst.Add("F");  
 
   Console.WriteLine("Number of elements: " +  
                      lst.Count);  
 
   Console.WriteLine("Removing 2 elements");  
   // Remove elements from the array list.  
   lst.Remove("F");  
   lst.Remove("A");  
 
   Console.WriteLine("Number of elements: " +  
                      lst.Count);  
 }

}

 </source>

new List<T>()

<source lang="csharp"> using System.Collections.Generic; using System;

class MainClass {

   public static void Main(string[] args)
   {
       List<MyClass> list = new List<MyClass>();
       list.Add(new MyClass());
       MyClass ass2 = list[0];
       Console.WriteLine("\nFound in list: {0}", ass2);
   }

} class MyClass {

  public override string ToString(){
   
     return "my class";
  }
   

}

 </source>