strings
DESCRIPTION
string s for dot netTRANSCRIPT
Declaration of string
1. strings are objects.2. string is a reference type.
1. static string Copy(string str)
2. int CompareTo(string str)
3. int IndexOf(string str)
4. int LastIndexOf(string str)
5. string ToLower( )
6. string ToUpper( )A string is a set of characters enclosed by double quotes. For example,
"this is a test"
is a string.
using System;
class MainClass{ static void Main(string[] args) { string MyString = "Hello World"; string Path = @"c:\Program Files"; string Path2 = "c:\\Program Files";
string Name = "Joe";
}}
String is object
using System;
class MainClass{ static void Main(string[] args) { string strOriginal = "Original String"; Console.WriteLine( "Value of strOriginal before call: {0}", strOriginal );
TryToAlterString( strOriginal );
Console.WriteLine( "Value of strOriginal after call: {0}", strOriginal ); }
static void TryToAlterString(string str) { str = "Modified String"; }}
Empty string
using System;using System.IO;using System.Text;
public class MainClass{ public static void Main(string[] args) { string address = String.Empty; }}
Use Indexer to reference chars in a string
using System;
class MainClass{
public static void Main() { string myString = "To be or not to be";
for (int count = 0; count < myString.Length; count++) { Console.WriteLine("myString[" + count + "] = " + myString[count]); }
}
}
Use the Compare() method to compare strings
using System;
class MainClass{
public static void Main() { int result; result = String.Compare("bbc", "abc"); Console.WriteLine("String.Compare(\"bbc\", \"abc\") = " + result); result = String.Compare("abc", "bbc"); Console.WriteLine("String.Compare(\"abc\", \"bbc\") = " + result); result = String.Compare("bbc", "bbc"); Console.WriteLine("String.Compare(\"bbc\", \"bbc\") = " + result); result = String.Compare("bbc", "BBC", true); Console.WriteLine("String.Compare(\"bbc\", \"BBC\", true) = " + result); result = String.Compare("bbc", "BBC", false); Console.WriteLine("String.Compare(\"bbc\", \"BBC\", false) = " + result); result = String.Compare("Hello World", 6, "Goodbye World", 8, 5); Console.WriteLine("String.Compare(\"Hello World\", 6, " + "\"Goodbye World\", 8, 5)
}
}
Use the Concat() method to concatenate strings
using System;
class MainClass{
public static void Main() { string myString4 = String.Concat("A, ", "B"); Console.WriteLine("String.Concat(\"A, \", \"B\") = "+ myString4); string myString5 = String.Concat("A, ", "B, ", "and countrymen"); Console.WriteLine("String.Concat(\"A, \", \"B, \", " + "\"and countrymen\") = " + myString5); }
}
Use the addition operator (+) to concatenate strings
using System;
class MainClass{
public static void Main() { string myString6 = "To be, " + "or not to be"; Console.WriteLine("\"To be, \" + \"or not to be\" = " + myString6); }
}
Use the Copy() method to copy a string
using System;
class MainClass{
public static void Main() { string myString4 = "string4"; Console.WriteLine("myString4 = " + myString4); Console.WriteLine("Copying myString4 to myString7 using Copy()"); string myString7 = String.Copy(myString4); Console.WriteLine("myString7 = " + myString7); }
}
Use the Equals() method and equality operator to check if two strings are equal
using System;
class MainClass{
public static void Main() { bool boolResult; string myString = "str"; string myString2 = "str2"; boolResult = String.Equals("bbc", "bbc"); Console.WriteLine("String.Equals(\"bbc\", \"bbc\") is " + boolResult); boolResult = myString.Equals(myString2); Console.WriteLine("myString.Equals(myString2) is " + boolResult); boolResult = myString == myString2; Console.WriteLine("myString == myString2 is " + boolResult); }
}
Use the Format() method to format a string
using System;
class MainClass{
public static void Main() { float myFloat = 1234.56789f; string myString8 = String.Format("{0, 10:f3}", myFloat); Console.WriteLine("String.Format(\"{0, 10:f3}\", myFloat) = " + myString8); }
}
Use the Format() method to format a string
using System;
class MainClass{
public static void Main() { float myFloat = 1234.56789f; string myString8 = String.Format("{0, 10:f3}", myFloat); Console.WriteLine("String.Format(\"{0, 10:f3}\", myFloat) = " + myString8); }
}
Use the Join() method to join strings
using System;
class MainClass{
public static void Main() { string[] myStrings = {"To", "be", "or", "not", "to", "be"}; string myString9 = String.Join(".", myStrings); Console.WriteLine("myString9 = " + myString9); }
}
Use the Split() method to split strings
using System;
class MainClass{
public static void Main() { string[] myStrings = {"To", "be", "or", "not", "to", "be"}; string myString9 = String.Join(".", myStrings); myStrings = myString9.Split('.'); foreach (string mySplitString in myStrings) { Console.WriteLine("mySplitString = " + mySplitString); } }
}
Use the IndexOfAny() and LastIndexOfAny() methods to search for character arrays in a string
using System;
class MainClass{
public static void Main() {
string[] myStrings = {"To", "be", "or", "not", "to", "be"}; string myString = String.Join(".", myStrings); char[] myChars = {'b', 'e'}; int index = myString.IndexOfAny(myChars); Console.WriteLine("'b' and 'e' occur at index " + index + " of myString"); index = myString.LastIndexOfAny(myChars); Console.WriteLine("'b' and 'e' last occur at index " + index + " of myString");
}}
Use the Insert(), Remove(), and Replace() methods to modify strings
using System;
class MainClass{
public static void Main() { string[] myStrings = {"To", "be", "or", "not", "to", "be"}; string myString = String.Join(".", myStrings); string myString10 = myString.Insert(6, "A, "); Console.WriteLine("myString.Insert(6, \"A, \") = " + myString10); string myString11 = myString10.Remove(14, 7); Console.WriteLine("myString10.Remove(14, 7) = " + myString11); string myString12 = myString11.Replace(',', '?'); Console.WriteLine("myString11.Replace(',', '?') = " + myString12); string myString13 = myString12.Replace("to be", "Or not to be A"); Console.WriteLine("myString12.Replace(\"to be\", \"Or not to be A\") = " + myString13); }
}
Use the PadLeft() and PadRight() methods to align strings
using System;
class MainClass{
public static void Main() { string[] myStrings = {"To", "be", "or", "not", "to", "be"}; string myString = String.Join(".", myStrings); string myString14 = '(' + myString.PadLeft(20) + ')'; Console.WriteLine("'(' + myString.PadLeft(20) + ')' = " + myString14); string myString15 = '(' + myString.PadLeft(20, '.') + ')'; Console.WriteLine("'(' + myString.PadLeft(20, '.') = " + myString15); string myString16 = '(' + myString.PadRight(20) + ')'; Console.WriteLine("'(' + myString.PadRight(20) + ')' = " + myString16); string myString17 = '(' + myString.PadRight(20, '.') + ')'; Console.WriteLine("'(' + myString.PadRight(20, '.') + ')' = " + myString17);
}
}
Use the Trim(), TrimStart(), and TrimEnd() methods to trim strings
using System;
class MainClass{
public static void Main() { string myString18 = '(' + " Whitespace ".Trim() + ')'; Console.WriteLine("'(' + \" Whitespace \".Trim() + ')' = " + myString18); string myString19 = '(' + " Whitespace ".TrimStart() + ')'; Console.WriteLine("'(' + \" Whitespace \".TrimStart() + ')' = " + myString19); string myString20 = '(' + " Whitespace ".TrimEnd() + ')'; Console.WriteLine("'(' + \" Whitespace \".TrimEnd() + ')' = " + myString20);
}
}
Use the Substring() method to retrieve substrings
using System;
class MainClass{
public static void Main() { string[] myStrings = {"To", "be", "or", "not", "to", "be"}; string myString = String.Join(".", myStrings); string myString21 = myString.Substring(3); Console.WriteLine("myString.Substring(3) = " + myString21); string myString22 = myString.Substring(3, 2); Console.WriteLine("myString.Substring(3, 2) = " + myString22);
}
}