C# String Compare() (With Examples) - Programiz

The Compare() method compares two strings in the alphabetical order.

Example

using System; namespace CsharpString { class Test { public static void Main(string [] args) { string str1 = "C#"; string str2 = "Programiz"; // compares str1 with str2 // returns -1 because C# comes before Programiz in alphabetical order int result = String.Compare(str1, str2); Console.WriteLine(result); Console.ReadLine(); } } } // Output: -1

Compare() Syntax

The syntax of the string Compare() method is:

String.Compare(string str1, string str2)

Here, Compare() is a method of class String.

Compare() Parameters

The Compare() method takes the following parameters:

• str1 - first string for comparison
• str2 - second string for comparison

Compare() Return Value

The Compare() method returns:

• 0 - if the strings are equal
• positive integer - if the first string comes after the second string in the alphabetical order
• negative integer - if the first string comes before the second string in the alphabetical order

Example 1: C# String Compare()

using System; namespace CsharpString { class Test { public static void Main(string [] args) { string str1 = "C#"; string str2 = "C#"; string str3 = "Programiz"; int result; // compares str1 with str2 result = String.Compare(str1, str2); Console.WriteLine(result); //compares str1 with str3 result = String.Compare(str1, str3); Console.WriteLine(result); //compares str3 with str1 result = String.Compare(str3, str1); Console.WriteLine(result); Console.ReadLine(); } } }

Output

0 -1 1

Here,

• String.Compare(str1, str2) returns 0 since str1 and str2 are equal
• String.Compare(str1, str3) returns -1 since str1 comes before str3
• String.Compare(str3, str1) returns 1 since str3 comes after str1

Example 2: Check if Two Strings Are Equal

using System; namespace CsharpString { class Test { public static void Main(string [] args) { string str1 = "C#"; string str2 = "C#"; // if str1 and str2 are equal, the result is 0 if(String.Compare(str1, str2) == 0) { Console.WriteLine("str1 and str2 are equal"); } else { Console.WriteLine("str1 and str2 are not equal."); } Console.ReadLine(); } } }

Output

str1 and str2 are equal

Since, str1 is equal to str2, String.Compare(str1, str2) returns 0.

Example 3: C# String Compare() With Case

using System; namespace CsharpString { class Test { public static void Main(string [] args) { string str1 = "Programiz"; string str2 = "programiz"; int result; // compares str1 and str2 result = String.Compare(str1, str2); Console.WriteLine(result); Console.ReadLine(); } } }

Output

1

When "Programiz" is compared to "programiz", we do not get 0. It is because the Compare() method considers the letter case.

Example 4: C# String Compare() - Ignore Case

using System; namespace CsharpString { class Test { public static void Main(string [] args) { string str1 = "Programiz"; string str2 = "programiz"; int result; bool ignoreCase = true; // compares by ignoring case result = String.Compare(str1, str2, ignoreCase); Console.WriteLine(result); Console.ReadLine(); } } }

Output

0

When "Programiz" is compared to "programiz", we get 0. This is because we have the Boolean value true in the method parameter, which ignores the case during string comparison.

Notes:

• Boolean value false considers the letter case during string comparison.
• We can have additional parameters in the String.Compare() method, like bool ignorecase.