static void Main(string[] args)
{
// non-generic version of collection
Stack myStack = new Stack();
myStack.Push("a string");
myStack.Push(123);
myStack.Push(3.3);
myStack.Push(myStack);
Console.WriteLine(myStack);
//Console.WriteLine(myStack.Pop().GetType());
//double aDobule = (double)myStack.Pop();
//Console.WriteLine(myStack.Pop().GetType());
//Console.WriteLine(myStack.Pop().GetType());
//Console.WriteLine(myStack.Pop().GetType());
// generic version of collections
Stack <string> stringStack = new Stack <string>();
stringStack.Push("a string");
//stringStack.Push(123);
string myStr = stringStack.Pop();
var intStack = new Stack <int>();
intStack.Push(123);
//intStack.Push("a string");
short aShort = 10;
intStack.Push(aShort);
long aLong = 100L;
intStack.Push((int)aLong);
GenericList <int> intList = new GenericList <int>();
intList.AddHead(1);
intList.AddHead(2);
intList.AddHead(3);
Console.WriteLine(intList);
GenericList <string> strList = new GenericList <string>();
strList.AddHead("Added First, Displayed Last!");
strList.AddHead("Added Second, Displayed Second!");
strList.AddHead("Added Last, Displayed First!");
Console.WriteLine(strList);
var doubleList = new GenericList <double>();
doubleList.AddHead(1.1);
doubleList.AddHead(2.2);
doubleList.AddHead(3.3);
Console.WriteLine(doubleList);
foreach (var item in doubleList)
{
Console.WriteLine(item + " - ");
}
// value types:
int intVal = 10;
// reference types:
object intValAsRefType = intVal; // boxing
int anotherVal = (int)intValAsRefType; // unboxing
// type-safety
//foreach (int item in myStack)
//{
// Console.WriteLine(item);
//}// end of foreach loop
int x = 5;
int y = 10;
Swap(ref x, ref y);
Console.WriteLine("x = " + x + ", y = " + y);
double d1 = 2.2;
double d2 = 5.5;
Swap(ref d1, ref d2);
Console.WriteLine("d1 = " + d1 + ", d2 = " + d2);
string s1 = "first";
string s2 = "second";
Swap(ref s1, ref s2);
Console.WriteLine("s1 = " + s1 + ", s2 = " + s2);
GenericList <int> anotherList = new GenericList <int>();
anotherList.AddHead(111);
anotherList.AddHead(222);
anotherList.AddHead(333);
Swap(ref intList, ref anotherList);
Console.WriteLine(intList);
Console.WriteLine(anotherList);
}// end of Main()
static void Main(string[] args)
{
// non-generic version of a collection
Stack myStack = new Stack();
myStack.Push("a string");
myStack.Push(123);
myStack.Push(3.3);
//myStack.Push(myStack);
Console.WriteLine(myStack.Peek());
Console.WriteLine(myStack.Peek().GetType());
double aDouble = (double)myStack.Pop(); //unboxing
Console.WriteLine(aDouble + " unboxed");
Console.WriteLine(myStack.Peek().GetType());
//double aInt = (double)myStack.Pop(); //since the current item is an int. it will give a invalidCastException
Console.WriteLine(myStack.Peek().GetType());
// generic version of a collection
Stack <string> stringStack = new Stack <string>();
stringStack.Push("Apples");
stringStack.Push("Grapes");
//stringStack.Push(123); //compiler won't let you add different types (C#&Java are strongly typed)
string myStr = stringStack.Pop(); // pop grapes
Console.WriteLine(stringStack.Pop());
var intStack = new Stack <int>();
intStack.Push(123);
//intStack.Push(3.3); // can't put double in intstack
Console.WriteLine(intStack.Pop());
short aShort = 10;
intStack.Push(aShort); //implicit conversion from short to int happens
long aLong = 10505050505050L;
//intStack.Push(aLong); //implicit conversion doesn't work from long to int
intStack.Push((int)aLong); // this works because you convert it first, but the
// value might change when you cast long to int
Console.WriteLine(intStack.Pop());
GenericList <string> strList = new GenericList <string>();
strList.AddHead("Apples");
strList.AddHead("Grapes");
strList.AddHead("Peaches");
strList.AddHead("Pears");
Console.WriteLine(strList);
strList.AddFoot("Nectarines");
strList.AddFoot("Raspberries");
Console.WriteLine(strList);
GenericList <int> intList = new GenericList <int>();
intList.AddHead(5);
intList.AddHead(2);
intList.AddHead(9);
intList.AddHead(4);
Console.WriteLine(intList);
intList.AddFoot(1);
intList.AddFoot(8);
Console.WriteLine(intList);
var doubleList = new GenericList <double>();
doubleList.AddHead(5.5);
doubleList.AddHead(2.2);
doubleList.AddHead(9.9);
doubleList.AddHead(4.4);
Console.WriteLine(doubleList);
doubleList.AddFoot(1.8);
doubleList.AddFoot(8.85);
Console.WriteLine(doubleList);
foreach (var item in strList)
{
Console.WriteLine(item + " -");
}
foreach (var item in intList)
{
Console.WriteLine(item + " -");
}
foreach (var item in doubleList)
{
Console.WriteLine(item + " -");
}
// value types:
int intVal = 10;
// reference types:
object IntValAsRefType = intVal; //boxing
int anotherVal = (int)IntValAsRefType;
// you can only convert if you know what the type is otherwise it could act weird.
Console.WriteLine(anotherVal);
//All the collections store references to objects not the full objects themselves
// so the stuff in nongeneric myStack above is being boxed as on object reference with each Push
// this causes extra time.
// Type-safety
/*foreach (var item in myStack)
* {
* Console.WriteLine(item);
* } */
int x = 5;
int y = 10;
Swap(ref x, ref y);
Console.WriteLine("x=" + x + ", y=" + y);
double d1 = 2.2;
double d2 = 5.5;
Swap(ref d1, ref d2);
Console.WriteLine("d1=" + d1 + ", d2=" + d2);
string s1 = "first";
string s2 = "second";
Swap(ref s1, ref s2);
Console.WriteLine("s1=" + s1 + ", s2=" + s2);
String st1 = "aaa";
String st2 = "zzz";
Swap(ref st1, ref st2);
Console.WriteLine("st1=" + st1 + ", st2=" + st2);
var anotherList = new GenericList <int>();
anotherList.AddFoot(20);
anotherList.AddHead(50);
Console.WriteLine(intList);
Console.WriteLine(anotherList);
Swap(ref intList, ref anotherList); // types must be the same
Console.WriteLine("s1=" + d1 + ", s2=" + d2);
// simple arrays
string[] fruits = { "Apple", "Orange", "Grapes" };
Console.WriteLine(fruits[1]);
fruits[2] = "Banana";
int[] weights = new int[10];
Console.WriteLine(weights[0]);
string[,] sections = new string[3, 2];
sections[0, 0] = "top left";
sections[0, 1] = "top right";
//List
var fruitlist = new List <string>();
fruitlist.Add("apple");
fruitlist.Add("orange");
fruitlist.Add("banana");
Console.WriteLine(fruitlist);
foreach (var item in fruitlist)
{
Console.WriteLine(item);
}
fruitlist.Sort();
foreach (var item in fruitlist)
{
Console.WriteLine(item);
}
// Dictionary
var inventory = new Dictionary <string, double>();
inventory.Add("Apple", 19);
inventory.Add("Orange", 49);
inventory.Add("Banana", 57);
var keys = inventory.Keys;
foreach (var item in keys)
{
Console.WriteLine("Key: " + item);
Console.WriteLine("Value: " + inventory[item]);
// if key doesn't exist the line above will have an exception
}
double value;
//Try to get the value of key 'watermelon' which doesn't exit
if (inventory.TryGetValue("Watermelon", out value))
{
Console.WriteLine("Watermelon inventory: " + value);
}
else
{
Console.WriteLine("Watermelon not found in inventory");
}
if (inventory.TryGetValue("Apple", out value))
{
Console.WriteLine("Apples left: " + inventory["Apple"]);
Console.WriteLine("Costumer bought 15 apples");
inventory["Apple"] = value - 15; // person bought 19-4=15 apples 4 left
Console.WriteLine("Apples left: " + inventory["Apple"]);
}
var prices = new Dictionary <string, double>();
prices.Add("Apple", .79);
prices.Add("Orange", 1.15);
prices.Add("Banana", .54);
// a better way would be to search both lists
double totalBeforeTax = 0;
if (prices.TryGetValue("Apple", out value))
{
Console.WriteLine("Apples cost: " + prices["Apple"]);
Console.WriteLine("Costumer bought 15 apples");
totalBeforeTax = prices["Apple"] * 15; // person bought 19-4=15 apples 4 left
Console.WriteLine("Apples Total cost before tax: " + totalBeforeTax + "\n");
}
//sorted list
var sortedList = new SortedList <string, string>();
sortedList.Add("first", "David");
sortedList.Add("second", "Smith");
sortedList.Add("last", "Jack");
var skeys = sortedList.Keys;
foreach (var item in skeys)
{
Console.WriteLine("key = " + item + ", Value = " + sortedList[item]);
}
var days = new SortedList <int, string>();
days.Add(1, "Sunday");
days.Add(2, "Monday");
days.Add(4, "Wednesday");
days.Add(7, "Saturday");
days.Add(6, "Friday");
days.Add(3, "Tuesday");
days.Add(5, "Thursday");
var dkeys = days.Keys;
foreach (var item in dkeys)
{
Console.WriteLine("Day: " + item + ", Value = " + days[item]);
}
sortedList.Remove("first");
} // endof main
