StringCompareVsCompareOrdinal.txt

String.Compare: Compares two specified String objects and returns an integer that indicates their relative position in the sort order.
String.CompareOrdinal: Compares two String objects by evaluating the numeric values of the corresponding Char objects in each string.

----------
20190927

This following example demonstrates that CompareOrdinal and Compare use different sort orders. 

using System;
using System.Globalization;

class Test 
{
	public static void Main(String[] args) 
	{
	String strLow = "abc";
	String strCap = "ABC";
	String result = "equal to ";
	int x = 0;
	int pos = 1;

// The Unicode codepoint for 'b' is greater than the codepoint for 'B'.
// Unicode 中, 字元 'b' 排在 'B' 之後.
	x = String.CompareOrdinal(strLow, pos, strCap, pos, 1);
	if (x < 0) result = "less than";
	if (x > 0) result = "greater than";
	Console.WriteLine("CompareOrdinal(\"{0}\"[{2}], \"{1}\"[{2}]):", strLow, strCap, pos);
	Console.WriteLine("   '{0}' is {1} '{2}'", strLow[pos], result, strCap[pos]);

// In U.S. English culture, 'b' is linguistically less than 'B'.
// 在 美式文化 中, 字元 'b' 語言排在 'B' 之前
	x = String.Compare(strLow, pos, strCap, pos, 1, false, new CultureInfo("en-US"));
	if (x < 0) result = "less than";
	else if (x > 0) result = "greater than";
	Console.WriteLine("Compare(\"{0}\"[{2}], \"{1}\"[{2}]):", strLow, strCap, pos);
	Console.WriteLine("   '{0}' is {1} '{2}'", strLow[pos], result, strCap[pos]);
	}
}

The indexA, indexB, and length parameters must be nonnegative. 
The number of characters compared is the lesser of the length of strA less indexA, the length of strB less indexB, and length. 
This method performs a case-sensitive comparison using ordinal sort rules. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions. To perform a case-insensitive comparison using ordinal sort rules, call the Compare(String, Int32, String, Int32, Int32, StringComparison) method with the comparisonType argument set to StringComparison.OrdinalIgnoreCase. 
Because CompareOrdinal(String, String) is a static method, strA and strB can be null. If both values are null, the method returns 0 (zero), which indicates that strA and strB are equal. If only one of the values is null, the method considers the non-null value to be greater.



The following example performs and ordinal comparison of two strings that only differ in case. 

// Sample for String.CompareOrdinal(String, String)
using System;

class Sample {
    public static void Main() {
    String str1 = "ABCD";
    String str2 = "abcd";
    String str;
    int result;

    Console.WriteLine();
    Console.WriteLine("Compare the numeric values of the corresponding Char objects in each string.");
    Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);
    result = String.CompareOrdinal(str1, str2);
    str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
    Console.Write("String '{0}' is ", str1);
    Console.Write("{0} ", str);
    Console.WriteLine("String '{0}'.", str2);
    }
}
/*
This example produces the following results:

Compare the numeric values of the corresponding Char objects in each string.
str1 = 'ABCD', str2 = 'abcd'
String 'ABCD' is less than String 'abcd'.
*/

This method performs a case-sensitive comparison using ordinal sort rules. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions. To perform a case-insensitive comparison using ordinal sort rules, call the Compare(String, String, StringComparison) method with the comparisonType argument set to StringComparison.OrdinalIgnoreCase. 
Because CompareOrdinal(String, String) is a static method, strA and strB can be null. If both values are null, the method returns 0 (zero), which indicates that strA and strB are equal. If only one of the values is null, the method considers the non-null value to be greater.