System.String.Compare Method

Compares substrings of two specified string objects using the specified rules, and returns an integer that indicates their relative position in the sort order.


public static int Compare (string strA, int indexA, string strB, int indexB, int length, StringComparison comparisonType)


The first string to use in the comparison.
The position of the substring within strA.
The second string to use in the comparison.
The position of the substring within strB.
The maximum number of characters in the substrings to compare.
One of the enumeration values that specifies the rules to use in the comparison.


A 32-bit signed integer that indicates the lexical relationship between the two comparands.

Less than zero

The substring in the strA parameter is less than the substring in the strB parameter.


The substrings are equal, or the length parameter is zero.

Greater than zero

The substring in strA is greater than the substring in strB.


The substrings to compare start in strA at indexA and in strB at indexB. Both indexA and indexB are zero-based; that is, the first character in strA and strB is at position zero, not position one. The length of the first substring is equal to the length of strA minus indexA plus one. The length of the second substring is equal to the length of strB minus indexB plus one.

The number of characters to compare is the lesser of the lengths of the two substrings, and length. The indexA, indexB, and length parameters must be nonnegative.

The comparisonType parameter indicates whether the comparison should use the current or invariant culture, honor or ignore the case of the comparands, or use word (culture-sensitive) or ordinal (culture-insensitive) sort rules.

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both substrings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, the string with remaining characters is considered greater. The return value is the result of the last comparison performed.

Unexpected results can occur when comparisons are affected by culture-specific casing rules. For example, in Turkish, the following example yields the wrong results because the file system in Turkish does not use linguistic casing rules for the letter "i" in "file".

code reference: System.String.Compare#8

Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:

code reference: System.String.Compare#9


Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions:,
Since: .NET 2.0