String Manipulation in C#

string start = "This is a ";
string end = "concatenated string!";

string concat = start + end;    
// concat = "This is a concatenated string!"

string start = "This is a ";
string end = "concatenated string!";

start += end;                 // start = "This is a concatenated string!"

string s1 = "String to compare.";
string s2 = "String to compare.";
string s3 = "String to Compare.";   // Note the capital 'C'
bool result;

result = s1 == s2;                  // result = true
result = s1 == s3;                  // result = false
result = s1 != s2;                  // result = false
result = s1 != s3;                  // result = true

string notNullString = "A string";
string nullString = null;
string nullTestString;

nullTestString = notNullString ?? "Null";     // nullTestString = "A string"
nullTestString = nullString ?? "Null";       // nullTestString = "Null"

string notNullString = "A string";
string nullString = null;
string nullTestString;

// Mimic the functionality of the null coalescing operator
nullTestString = notNullString == null ? "Null": notNullString;    
// "A string"
nullTestString = nullString == null ? "Null": nullString;    // "Null"

// Convert a string to an integer
int stringToInt = System.Convert.ToInt32("25");

// Convert a string to a decimal
decimal stringToDecimal = System.Convert.ToDecimal("25.5");

// Booleans can be converted too
bool stringToBoolean = System.Convert.ToBoolean("true");

decimal originalValue = 25.5M;
//Converting floating point number to an integer type
int converted = Convert.ToInt32(originalValue);     // Result is 26
//Casting floating point number to an integer type
int casted = (int)originalValue;                    // Result is 25

string toConvert = "100";
//Convert from string to int
int convertedInt = int.Parse(toConvert);            // Result is 100
//Convert from string to float
float convertedFloat = float.Parse(toConvert);      // Result is 100.0

// Conversion including thousands separator
int thousands = int.Parse("1,000", NumberStyles.AllowThousands);

// Conversion of value including a decimal point
float withDecimal = float.Parse("5.50", NumberStyles.AllowDecimalPoint);

// Conversion of value including a currency symbol
// (Make sure you change the currency symbol to match your local currency)
int withCurrency = int.Parse("£5", NumberStyles.AllowCurrencySymbol);

// Conversion of value including a decimal point and currency symbol
float multiple = float.Parse("£5.50", 
  NumberStyles.AllowDecimalPoint | NumberStyles.AllowCurrencySymbol);

object anObject = new object();
Console.WriteLine(anObject.ToString());     // Outputs "System.Object"

int quantity = 1500;
float price = 1.50F;

Console.WriteLine(quantity.ToString());            // Outputs "1500"
Console.WriteLine(price.ToString());               // Outputs "1.5"
Console.WriteLine(sold.ToString());                // Outputs "True"

int quantity = 1500;
float price = 1.50F;
float discount = 0.05F;

Console.WriteLine(quantity.ToString("n0"));        // Outputs "1,500"
Console.WriteLine(price.ToString("c"));            // Outputs "£1.50"
Console.WriteLine(discount.ToString("p1"));        // Outputs "5.0 %"

int small = 12;
int large = 123456;
float tiny = 1.234F;

Console.WriteLine(small.ToString("0000"));         // Outputs "0012"
Console.WriteLine(large.ToString("0000"));         // Outputs "123456"
Console.WriteLine(tiny.ToString("0000"));          // Outputs "0001"

int small = 12;
double large = 123456.789;
float tiny = 1.234F;

Console.WriteLine(small.ToString("00.00"));      // Outputs "12.00"
Console.WriteLine(large.ToString("00.00"));      // Outputs "123456.79"
Console.WriteLine(tiny.ToString("00.00"));       // Outputs "01.23"

int small = 12;
double large = 123456.789;
float tiny = 1.234F;

Console.WriteLine(small.ToString("##.##"));     // Outputs "12"
Console.WriteLine(large.ToString("##.##"));     // Outputs "123456.79"
Console.WriteLine(tiny.ToString("##.##"));      // Outputs "1.23"

int small = 12;
double large = 123456.789;
float tiny = 1.234F;

Console.WriteLine(small.ToString("#,#.00"));    // Outputs "12.00"
Console.WriteLine(large.ToString("#,#.##"));    // Outputs "123,456.79"
Console.WriteLine(tiny.ToString("#,#.##"));     // Outputs "1.23"

int small = 12;
double large = 123456.789;
float tiny = 0.0015F;

Console.WriteLine(small.ToString("#,#.#%"));  //Outputs "1,200%"
Console.WriteLine(large.ToString("#,#.#%"));  //Outputs "12,345,678.9%"
Console.WriteLine(tiny.ToString("#,#.#%"));   //Outputs ".2%"

int small = 12;
double large = 123456.789;
float tiny = 0.0015F;

Console.WriteLine(small.ToString("0.0E0"));      // Outputs "1.2E1"
Console.WriteLine(large.ToString("0.00e00"));    // Outputs "1.23e05"
Console.WriteLine(tiny.ToString("0.00E00"));     // Outputs "1.50E-03"

int small = 12;
double large = 123456.789;
float tiny = 0.0015F;

Console.WriteLine(small.ToString("0.0E-0"));      // Outputs "1.2E1"
Console.WriteLine(large.ToString("0.00e+00"));    // Outputs "1.23e+05"
Console.WriteLine(tiny.ToString("0.00E+00"));     // Outputs "1.50E-03"

Console.WriteLine(12345.ToString("00-00-00"));   // Outputs "01-23-45"
Console.WriteLine(12345.ToString("0'E'"));       // Outputs "12345E"

Console.WriteLine(123.45.ToString("\\'0.00\\'"));  //Outputs "'123.45'"
Console.WriteLine(12345.ToString("000\\\\000"));   //Outputs "012\345"

string output;
int selection = 5;

// Generate the output string
output = string.Format("You selected item {0} from the list.", selection);

Console.WriteLine(output);	 //Outputs "You selected item 5 from the list."

string output;
int selection = 5;
int count = 10;

// Generate the output string
output = string.Format("You selected item {0} from {1}.", selection, count);

Console.WriteLine(output);     //Outputs "You selected item 5 from 10."

string output;
int value = 100;

// Convert a number to hexadecimal
output = string.Format("The decimal value {0} = {0:X} in hex.", value);

Console.WriteLine(output);   // Outputs "The decimal value 100 = 64 in hex."

string output;
int value = 100;

// Convert a number to hexadecimal
output = string.Format("{{The decimal value {0} = {0:X} in hex.}}", value);

Console.WriteLine(output);   // Outputs "{The decimal value 100 = 64 in hex.}"

int value = 100;
// Convert a number to hexadecimal
Console.WriteLine("{{The decimal value {0} = {0:X} in hex.}}", value);

string inputted = "  BlackWasp  ";

Console.WriteLine(inputted.TrimStart());        //Outputs "BlackWasp  "
Console.WriteLine(inputted.TrimEnd());          // Outputs "BlackWasp"
Console.WriteLine(inputted.Trim());             // Outputs "BlackWasp"

string original = "  BlackWasp  ";
string trimmed = original.Trim();

Console.WriteLine(original);                    // Outputs "BlackWasp"  
Console.WriteLine(trimmed);                     // Outputs "BlackWasp"

string value1 = "£1.00";
string value2 = "£10.00";
string value3 = "£100.00";

// Output a right-aligned column
Console.WriteLine(value1.PadLeft(8));           // Outputs "   £1.00"
Console.WriteLine(value2.PadLeft(8));           // Outputs "  £10.00"
Console.WriteLine(value3.PadLeft(8));           // Outputs " £100.00"

// Output a left-aligned column
Console.WriteLine(value1.PadRight(8));          // Outputs "£1.00   "
Console.WriteLine(value2.PadRight(8));          // Outputs "£10.00  "
Console.WriteLine(value3.PadRight(8));          // Outputs "£100.00 "

// Trying to pad a string that is too long
Console.WriteLine(value1.PadRight(3));          // Outputs "£1.00"

string value = "£1.00";

Console.WriteLine(value.PadLeft(8,'.'));        // Outputs "...£1.00"
Console.WriteLine(value.PadRight(8,'_'));       // Outputs "£1.00___"

string webSite = "BlackWasp";

Console.WriteLine(webSite.ToLower());           // Outputs "blackwasp"
Console.WriteLine(webSite.ToUpper());           // Outputs "BLACKWASP"

string start = "This is a ";
string end = "concatenated string!";

string concat = start + end;    // concat = "This is a concatenated string!"

string start = "This is a ";
string end = "concatenated string!";

string concat = string.Concat(start, end);

string template = "Please ask for  on arrival.";
string tutor = "Ujjwal";

Console.WriteLine(template.Insert(15, tutor));

// Outputs: "Please ask for Ujjwal on arrival."

string sample = "The quick brown fox jumps over the lazy dog.";

string result = sample.Remove(16);  // result = "The quick brown "
result = sample.Remove(16, 24);     // result = "The quick brown dog."

string sample = "The quick brown fox jumps over the lazy dog.";

string result = sample.Substring(16);   // result = "fox jumps over the lazy dog."
result = sample.Substring(16, 24);      // result = "fox jumps over the lazy "

string sample = "The brown fox.";

string result = sample.Replace("brown", "red"));  // result = "The red fox."

string sample = "The brown fox.";

string result = string.Copy(sample);    // result = "The brown fox." ,

string s1 = "String to compare.";
string s2 = "String to compare.";
string s3 = "String to Compare.";   // Note the capital 'C'
bool result;

result = s1 == s2;                  // result = true
result = s1 == s3;                  // result = false
result = s1 != s2;                  // result = false
result = s1 != s3;                  // result = true

string animal1 = "Cat";
string animal2 = "Dog";
int result;

result = animal1.CompareTo("Cat");       // result is zero
result = animal2.CompareTo("Cat");       // result is greater than zero
result = animal1.CompareTo(animal2);     // result is less than zero

string animal = null;
int result;

result = animal.CompareTo("Cat");           // Causes an exception

string animal1 = "Cat";
string animal2 = "Dog";
int result;

result = String.Compare(animal1, "Cat");    //result is zero
result = String.Compare(animal2, "Cat");    //result is greater than zero
result = String.Compare(animal1, animal2);  //result is less than zero

string animal = "Cat";
int result;

result = String.Compare(animal, null);      // result is greater than     zero
result = String.Compare(null, animal);      // result is less than zero
result = String.Compare(null, null);        // result is zero

string animal1 = "Cat";
string animal2 = "cat";                      // Note use of lower case
int result;

result = String.Compare(animal1, animal2, true);   // Strings are equal
result = String.Compare(animal1, animal2, false);  // Strings are not equal

string animal1 = "Cat";
string animal2 = "cat";                       // Note use of lower case
int result;

result = String.Compare(animal1, animal2);  	//result is greater than zero
result = String.CompareOrdinal(animal1, animal2);   // result is less than zero

string animal = "Cat";
bool result;

result = animal.Equals("Cat");                      // result = true
result = animal.Equals("cat");                      // result = false
result = String.Equals(animal, "Cat");              // result = true
result = String.Equals(animal, "cat");              // result = false

string animal1 = "Cat";
string animal2 = "";
string animal3 = null;
bool result;

result = String.IsNullOrEmpty(animal1);             // result = false
result = String.IsNullOrEmpty(animal2);             // result = true
result = String.IsNullOrEmpty(animal3);             // result = true

string animal = "Dog";
int result;

result = animal.Length;                     // result is 3
result = "Elephant".Length;                 // result is 8

string phrase = "The quick brown fox jumps over the lazy dog.";
int result;

result = phrase.IndexOf("brown");           // result is 10
result = phrase.LastIndexOf("dog");         // result is 40
result = phrase.IndexOf("green");           // result is -1
result = phrase.LastIndexOf("blue");        // result is -1

string phrase = "The quick brown fox jumps over the lazy dog.";
int result;

result = phrase.IndexOf("he");              // result is 1
result = phrase.IndexOf("he", 1);           // result is 1
result = phrase.IndexOf("he", 2);           // result is 32
result = phrase.LastIndexOf("he");          // result is 32
result = phrase.LastIndexOf("he",33);       // result is 32
result = phrase.LastIndexOf("he",32);       // result is 1

string phrase = "The quick brown fox jumps over the lazy dog.";
int result;

result = phrase.IndexOf("brown");           // result is 10
result = phrase.IndexOf("brown", 5, 4);     // result is -1
result = phrase.LastIndexOf("fox");         // result is 16
result = phrase.LastIndexOf("he", 25, 5);   // result is -1

string phrase = "The quick brown fox jumps over the lazy dog.";
bool result;

result = phrase.StartsWith("The quick");    // result is true
result = phrase.StartsWith("lazy dog.");    // result is false
result = phrase.EndsWith("lazy dog.");      // result is true
result = phrase.EndsWith("The quick");      // result is false

string phrase = "The quick brown fox jumps over the lazy dog.";
bool result;

result = phrase.Contains("brown fox");      // result is true
result = phrase.Contains("lazy fox.");      // result is false

using System;
using System.Collections.Generic;
using System.Text;

namespace testEnum
{
    //declare enum
    public enum Volume
    {
        Low,
        Medium,
        High
    }

    class Program
    {
        static void Main(string[] args)
        {
            Volume myVol=new Volume();
            string choice;
            for (int i = 1; i > 0; )
            {
                Console.WriteLine("1. Low");
                Console.WriteLine("2. Medium");
                Console.WriteLine("3. High");
                Console.WriteLine("Please enter your choice....");
                choice = Console.ReadLine();
                // create and initialize instance of enum type
                if (choice == "1")
                {
                    myVol = Volume.Low;
                    i++;
                }
                else if (choice == "2")
                {
                    myVol = Volume.Medium;
                    i++;
                }
                else if (choice == "3")
                {
                    myVol = Volume.High;
                    i++;
                }
                else
                {
                    Console.WriteLine("This is invalid choice." );
                    i = 0;
                    break;
                }

                // make decision based on enum value
                switch (myVol)
                {
                    case Volume.Low:
                        Console.WriteLine("The volume has been turned Down.");
                        break;
                    case Volume.Medium:
                        Console.WriteLine("The volume is in the middle.");
                        break;
                    case Volume.High:
                        Console.WriteLine("The volume has been turned up.");
                        break;
                }
                Console.ReadLine();
            } 
        }
    }
}

using System;
using System.Collections.Generic;
using System.Text;

namespace testArray
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] myIntArray;          // Declare the array.

            myIntArray = new int[11];   // Instantiate the array.

            for (int i = 0; i < 11; i++)   // Set the values.
                myIntArray[i] = i * 10;

            // Read and display the values of each element.
            for (int i = 0; i < 11; i++)
                Console.WriteLine("Value of element {0} = {1}", i, myIntArray[i]);
            Console.ReadLine();
        }
    }
}