// Code in the main function is executed
static void Main(string[] args)
{
// ---------- STRUCTS ----------
Customers bob = new Customers();
bob.createCust("Bob", 15.50, 12345);
bob.showCust();
}
// Code in the main function is executed
static void Main(string[] args)
{
// Prints string out to the console with a line break (Write = No Line Break)
Console.WriteLine("What is your name : ");
// Accept input from the user
string name = Console.ReadLine();
// You can combine Strings with +
Console.WriteLine("Hello " + name);
// ---------- DATA TYPES ----------
// Booleans are true or false
bool canVote = true;
// Characters are single 16 bit unicode characters
char grade = 'A';
// Integer with a max number of 2,147,483,647
int maxInt = int.MaxValue;
// Long with a max number of 9,223,372,036,854,775,807
long maxLong = long.MaxValue;
// Decimal has a maximum value of 79,228,162,514,264,337,593,543,950,335
// If you need something bigger look up BigInteger
decimal maxDec = decimal.MaxValue;
// A float is a 32 bit number with a maxValue of 3.402823E+38 with 7 decimals of precision
float maxFloat = float.MaxValue;
// A float is a 32 bit number with a maxValue of 1.797693134E+308 with 15 decimals of precision
double maxDouble = double.MaxValue;
// You can combine strings with other values with +
Console.WriteLine("Max Int : " + maxDouble);
// The dynamic data type is defined at run time
dynamic otherName = "Paul";
otherName = 1;
// The var data type is defined when compiled and then can't change
var anotherName = "Tom";
// ERROR : anotherName = 2;
Console.WriteLine("Hello " + anotherName);
// How to get the type and how to format strings
Console.WriteLine("anotherName is a {0}", anotherName.GetTypeCode());
// ---------- MATH ----------
Console.WriteLine("5 + 3 = " + (5 + 3));
Console.WriteLine("5 - 3 = " + (5 - 3));
Console.WriteLine("5 * 3 = " + (5 * 3));
Console.WriteLine("5 / 3 = " + (5 / 3));
Console.WriteLine("5.2 % 3 = " + (5.2 % 3));
int i = 0;
Console.WriteLine("i++ = " + (i++));
Console.WriteLine("++i = " + (++i));
Console.WriteLine("i-- = " + (i--));
Console.WriteLine("--i = " + (--i));
Console.WriteLine("i += 3 " + (i += 3));
Console.WriteLine("i -= 2 " + (i -= 2));
Console.WriteLine("i *= 2 " + (i *= 2));
Console.WriteLine("i /= 2 " + (i /= 2));
Console.WriteLine("i %= 2 " + (i %= 2));
// Casting : If no magnitude is lost casting happens automatically, but otherwise it must be done
// like this
double pi = 3.14;
int intPi = (int)pi; // put the data type to convert to between braces
// Math Functions
// Acos, Asin, Atan, Atan2, Cos, Cosh, Exp, Log, Sin, Sinh, Tan, Tanh
double number1 = 10.5;
double number2 = 15;
Console.WriteLine("Math.Abs(number1) " + (Math.Abs(number1)));
Console.WriteLine("Math.Ceiling(number1) " + (Math.Ceiling(number1)));
Console.WriteLine("Math.Floor(number1) " + (Math.Floor(number1)));
Console.WriteLine("Math.Max(number1, number2) " + (Math.Max(number1, number2)));
Console.WriteLine("Math.Min(number1, number2) " + (Math.Min(number1, number2)));
Console.WriteLine("Math.Pow(number1, 2) " + (Math.Pow(number1, 2)));
Console.WriteLine("Math.Round(number1) " + (Math.Round(number1)));
Console.WriteLine("Math.Sqrt(number1) " + (Math.Sqrt(number1)));
// Random Numbers
Random rand = new Random();
Console.WriteLine("Random Number Between 1 and 10 " + (rand.Next(1, 11)));
// ---------- CONDITIONALS ----------
// Relational Operators : > < >= <= == !=
// Logical Operators : && || ^ !
// If Statement
int age = 17;
if ((age >= 5) && (age <= 7))
{
Console.WriteLine("Go to elementary school");
}
else if ((age > 7) && (age < 13))
{
Console.WriteLine("Go to middle school");
}
else
{
Console.WriteLine("Go to high school");
}
if ((age < 14) || (age > 67))
{
Console.WriteLine("You shouldn't work");
}
Console.WriteLine("! true = " + (!true));
// Ternary Operator
bool canDrive = age >= 16 ? true : false;
// Switch is used when you have limited options
// Fall through isn't allowed with C# unless there are no statements between cases
// You can't check multiple values at once
switch (age)
{
case 0:
Console.WriteLine("Infant");
break;
case 1:
case 2:
Console.WriteLine("Toddler");
// Goto can be used to jump to a label elsewhere in the code
goto Cute;
default:
Console.WriteLine("Child");
break;
}
// Lable we can jump to with Goto
Cute:
Console.WriteLine("Toddlers are cute");
// ---------- LOOPING ----------
int i = 0;
while (i < 10)
{
// If i = 7 then skip the rest of the code and start with i = 8
if (i == 7)
{
i++;
continue;
}
// Jump completely out of the loop if i = 9
if (i == 9)
{
break;
}
// You can't convert an int into a bool : Print out only odds
if ((i % 2) > 0)
{
Console.WriteLine(i);
}
i++;
}
// The do while loop will go through the loop at least once
string guess;
do
{
Console.WriteLine("Guess a Number ");
guess = Console.ReadLine();
} while (!guess.Equals("15")); // How to check String equality
// Puts all changes to the iterator in one place
for (int j = 0; j < 10; j++)
{
if ((j % 2) > 0)
{
Console.WriteLine(j);
}
}
// foreach cycles through every item in an array or collection
string randStr = "Here are some random characters";
foreach (char c in randStr)
{
Console.WriteLine(c);
}
// ---------- STRINGS ----------
// Escape Sequences : \' \" \\ \b \n \t
string sampString = "A bunch of random words";
// Check if empty
Console.WriteLine("Is empty " + String.IsNullOrEmpty(sampString));
Console.WriteLine("Is empty " + String.IsNullOrWhiteSpace(sampString));
Console.WriteLine("String Length " + sampString.Length);
// Find a string index (Starts with 0)
Console.WriteLine("Index of bunch " + sampString.IndexOf("bunch"));
// Get a substring
Console.WriteLine("2nd Word " + sampString.Substring(2, 6));
string sampString2 = "More random words";
// Are strings equal
Console.WriteLine("Strings equal " + sampString.Equals(sampString2));
// Compare strings
Console.WriteLine("Starts with A bunch " + sampString.StartsWith("A bunch"));
Console.WriteLine("Ends with words " + sampString.EndsWith("words"));
// Trim white space at beginning and end or (TrimEnd / TrimStart)
sampString = sampString.Trim();
// Replace words or characters
sampString = sampString.Replace("words", "characters");
Console.WriteLine(sampString);
// Remove starting at a defined index up to the second index
sampString = sampString.Remove(0, 2);
Console.WriteLine(sampString);
// Join values in array and save to string
string[] names = new string[3] {
"Matt", "Joe", "Paul"
};
Console.WriteLine("Name List " + String.Join(", ", names));
// Formatting : Currency, Decimal Places, Before Decimals, Thousands Separator
string fmtStr = String.Format("{0:c} {1:00.00} {2:#.00} {3:0,0}", 1.56, 15.567, .56, 1000);
Console.WriteLine(fmtStr.ToString());
// ---------- STRINGBUILDER ----------
// Each time you create a string you actually create another string in memory
// StringBuilders are used when you want to be able to edit a string without creating new ones
StringBuilder sb = new StringBuilder();
// Append a string to the StringBuilder (AppendLine also adds a newline at the end)
sb.Append("This is the first sentence.");
// Append a formatted string
sb.AppendFormat("My name is {0} and I live in {1}", "Derek", "Pennsylvania");
// Clear the StringBuilder
// sb.Clear();
// Replaces every instance of the first with the second
sb.Replace("a", "e");
// Remove characters starting at the index and then up to the defined index
sb.Remove(5, 7);
// Out put everything
Console.WriteLine(sb.ToString());
// ---------- ARRAYS ----------
// Declare an array
int[] randNumArray;
// Declare the number of items an array can contain
int[] randArray = new int[5];
// Declare and initialize an array
int[] randArray2 = { 1, 2, 3, 4, 5 };
// Get array length
Console.WriteLine("Array Length " + randArray2.Length);
// Get item at index
Console.WriteLine("Item 0 " + randArray2[0]);
// Cycle through array
for (int i = 0; i < randArray2.Length; i++)
{
Console.WriteLine("{0} : {1}", i, randArray2[i]);
}
// Cycle with foreach
foreach (int num in randArray2)
{
Console.WriteLine(num);
}
// Get the index of an item or -1
Console.WriteLine("Where is 1 " + Array.IndexOf(randArray2, 1));
string[] names = { "Tom", "Paul", "Sally" };
// Join an array into a string
string nameStr = string.Join(", ", names);
Console.WriteLine(nameStr);
// Split a string into an array
string[] nameArray = nameStr.Split(',');
// Create a multidimensional array
int[,] multArray = new int[5, 3];
// Create and initialize a multidimensional array
int[,] multArray2 = { { 0, 1 }, { 2, 3 }, { 4, 5 } };
// Cycle through multidimensional array
foreach (int num in multArray2)
{
Console.WriteLine(num);
}
// Cycle and have access to indexes
for (int x = 0; x < multArray2.GetLength(0); x += 1)
{
for (int y = 0; y < multArray2.GetLength(1); y += 1)
{
Console.WriteLine("{0} | {1} : {2}", x, y, multArray2[x, y]);
}
}
// ---------- LISTS ----------
// A list unlike an array automatically resizes
// Create a list and add values
List <int> numList = new List <int>();
numList.Add(5);
numList.Add(15);
numList.Add(25);
// Add an array to a list
int[] randArray = { 1, 2, 3, 4, 5 };
numList.AddRange(randArray);
// Clear a list
// numList.Clear();
// Copy an array into a List
List <int> numList2 = new List <int>(randArray);
// Create a List with array
List <int> numList3 = new List <int>(new int[] { 1, 2, 3, 4 });
// Insert in a specific index
numList.Insert(1, 10);
// Remove a specific value
numList.Remove(5);
// Remove at an index
numList.RemoveAt(2);
// Cycle through a List with foreach or
for (int i = 0; i < numList.Count; i++)
{
Console.WriteLine(numList[i]);
}
// Return the index for a value or -1
Console.WriteLine("4 is in index " + numList3.IndexOf(4));
// Does the List contain a value
Console.WriteLine("5 in list " + numList3.Contains(5));
// Search for a value in a string List
List <string> strList = new List <string>(new string[] { "Tom", "Paul" });
Console.WriteLine("Tom in list " + strList.Contains("tom", StringComparer.OrdinalIgnoreCase));
// Sort the List
strList.Sort();
// ---------- EXCEPTION HANDLING ----------
// All the exceptions
// msdn.microsoft.com/en-us/library/system.systemexception.aspx#inheritanceContinued
try
{
Console.Write("Divide 10 by ");
int num = int.Parse(Console.ReadLine());
Console.WriteLine("10 / {0} = {1}", num, (10 / num));
}
// Specifically catches the divide by zero exception
catch (DivideByZeroException ex)
{
Console.WriteLine("Can't divide by zero");
// Get additonal info on the exception
Console.WriteLine(ex.GetType().Name);
Console.WriteLine(ex.Message);
// Throw the exception to the next inline
// throw ex;
// Throw a specific exception
throw new InvalidOperationException("Operation Failed", ex);
}
// Catches any other exception
catch (Exception ex)
{
Console.WriteLine("An error occurred");
Console.WriteLine(ex.GetType().Name);
Console.WriteLine(ex.Message);
}
// ---------- CLASSES & OBJECTS ----------
Animal bulldog = new Animal(13, 50, "Spot", "Woof");
Console.WriteLine("{0} says {1}", bulldog.name, bulldog.sound);
// Console.WriteLine("No. of Animals " + Animal.getNumOfAnimals());
// ---------- ENUMS ----------
Temperature micTemp = Temperature.Low;
Console.Write("What Temp : ");
Console.ReadLine();
switch (micTemp)
{
case Temperature.Freeze:
Console.WriteLine("Temp on Freezing");
break;
case Temperature.Low:
Console.WriteLine("Temp on Low");
break;
case Temperature.Warm:
Console.WriteLine("Temp on Warm");
break;
case Temperature.Boil:
Console.WriteLine("Temp on Boil");
break;
}
// ---------- STRUCTS ----------
Customers bob = new Customers();
bob.createCust("Bob", 15.50, 12345);
bob.showCust();
// ---------- ANONYMOUS METHODS ----------
// An anonymous method has no name and its return type is defined by the return used in the method
GetSum sum = delegate(double num1, double num2)
{
return(num1 + num2);
};
Console.WriteLine("5 + 10 = " + sum(5, 10));
// ---------- LAMBDA EXPRESSIONS ----------
// A lambda expression is used to act as an anonymous function or expression tree
// You can assign the lambda expression to a function instance
Func <int, int, int> getSum = (x, y) => x + y;
Console.WriteLine("5 + 3 = " + getSum.Invoke(5, 3));
// Get odd numbers from a list
List <int> numList = new List <int> {
5, 10, 15, 20, 25
};
// With an Expression Lambda the input goes in the left (n) and the statements go on the right
List <int> oddNums = numList.Where(n => n % 2 == 1).ToList();
foreach (int num in oddNums)
{
Console.Write(num + ", ");
}
// ---------- FILE I/O ----------
// The StreamReader and StreamWriter allows you to create text files while reading and
// writing to them
string[] custs = new string[] { "Tom", "Paul", "Greg" };
using (StreamWriter sw = new StreamWriter("custs.txt"))
{
foreach (string cust in custs)
{
sw.WriteLine(cust);
}
}
string custName = "";
using (StreamReader sr = new StreamReader("custs.txt"))
{
while ((custName = sr.ReadLine()) != null)
{
Console.WriteLine(custName);
}
}
Console.Write("Hit Enter to Exit");
string exitApp = Console.ReadLine();
}
