Csharp/C Sharp/Data Types/String Compare

Compare strings

/*
C#: The Complete Reference 
by Herbert Schildt 
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Compare strings. 
 
using System; 
 
public class CompareDemo { 
  public static void Main() { 
    string str1 = "one"; 
    string str2 = "one"; 
    string str3 = "ONE"; 
    string str4 = "two"; 
    string str5 = "one, too"; 
 
 
    if(String.rupare(str1, str2) == 0) 
      Console.WriteLine(str1 + " and " + str2 + 
                        " are equal."); 
    else 
      Console.WriteLine(str1 + " and " + str2 + 
                        " are not equal."); 
 
 
    if(String.rupare(str1, str3) == 0) 
      Console.WriteLine(str1 + " and " + str3 + 
                        " are equal."); 
    else 
      Console.WriteLine(str1 + " and " + str3 + 
                        " are not equal."); 
 
    if(String.rupare(str1, str3, true) == 0) 
      Console.WriteLine(str1 + " and " + str3 + 
                        " are equal ignoring case."); 
    else 
      Console.WriteLine(str1 + " and " + str3 + 
                        " are not equal ignoring case."); 
 
     if(String.rupare(str1, str5) == 0) 
      Console.WriteLine(str1 + " and " + str5 + 
                        " are equal."); 
    else 
      Console.WriteLine(str1 + " and " + str5 + 
                        " are not equal."); 
  
    if(String.rupare(str1, 0, str5, 0, 3) == 0) 
      Console.WriteLine("First part of " + str1 + " and " + 
                        str5 + " are equal."); 
    else 
      Console.WriteLine("First part of " + str1 + " and " + 
                        str5 + " are not equal."); 
 
    int result = String.rupare(str1, str4); 
    if(result < 0) 
      Console.WriteLine(str1 + " is less than " + str4); 
    else if(result > 0) 
      Console.WriteLine(str1 + " is greater than " + str4); 
    else 
      Console.WriteLine(str1 + " equals " + str4); 
  } 
}

Comparing a String to the Beginning or End of a Second String

using System;
using System.Data;
using System.Text.RegularExpressions;
using System.Text;
class Class1{
        static void Main(string[] args){
      string head = "str";
      string test = "strVarName";
      Console.WriteLine(test.StartsWith(head));
      string tail = "Name";
      test = "strVarName";
      Console.WriteLine(test.EndsWith(tail));
        
    
    
      head = "str";
      test = "strVarName";
      Console.WriteLine(string.rupare(head, 0, test, 0, head.Length, true));
      tail = "Name";
      test = "strVarName";
      Console.WriteLine(string.rupare(tail, 0, test, (test.Length - tail.Length), tail.Length, true));
        }
}

String copy and equal

/*
Learning C# 
by Jesse Liberty
Publisher: O"Reilly 
ISBN: 0596003765
*/
 using System;
 namespace StringManipulation
 {
    public class TesterStringCopyEqual
    {
       public void Run()
       {
           string s1 = "abcd";
           string s2 = "ABCD";
           // the string copy method
           string s5 = string.Copy(s2);
           Console.WriteLine(
               "s5 copied from s2: {0}", s5);
           // copy with the overloaded operator
           string s6 = s5;
           Console.WriteLine("s6 = s5: {0}", s6);
           // member method
           Console.WriteLine(
               "\nDoes s6.Equals(s5)?: {0}",
               s6.Equals(s5));
           // static method
           Console.WriteLine(
               "Does Equals(s6,s5)?: {0}",
               string.Equals(s6,s5));
           // overloaded operator
           Console.WriteLine(
               "Does s6==s5?: {0}", s6 == s5);
       }
       static void Main()
       {
          TesterStringCopyEqual t = new TesterStringCopyEqual();
          t.Run();
       }
    }
 }

Test for equality between stings.

 
using System;
using System.Text;
class StringApp {
    static void Main(string[] args) {
        string s1 = "Hello ";
        string s2 = "World!";
        Console.WriteLine("s1 == s2: {0}", s1 == s2);
        Console.WriteLine();
    }
}

use the Compare() method to compare strings

 
using System;
class MainClass {
    public static void Main() {
        int result;
        result = String.rupare("bbc", "abc");
        Console.WriteLine("String.rupare(\"bbc\", \"abc\") = " + result);
        result = String.rupare("abc", "bbc");
        Console.WriteLine("String.rupare(\"abc\", \"bbc\") = " + result);
        result = String.rupare("bbc", "bbc");
        Console.WriteLine("String.rupare(\"bbc\", \"bbc\") = " + result);
        result = String.rupare("bbc", "BBC", true);
        Console.WriteLine("String.rupare(\"bbc\", \"BBC\", true) = " + result);
        result = String.rupare("bbc", "BBC", false);
        Console.WriteLine("String.rupare(\"bbc\", \"BBC\", false) = " + result);
        result = String.rupare("Hello World", 6, "Goodbye World", 8, 5);
        Console.WriteLine("String.rupare(\"Hello World\", 6, " + "\"Goodbye World\", 8, 5) = " + result);
    
    }
}

use the Equals() method and equality operator to check if two strings are equal

 
using System;
class MainClass {
    public static void Main() {
        string myString = String.Concat("Friends, ", "Romans");
        string myString2 = String.Concat("Friends");
        bool boolResult;
        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);
    }
}