O'Reilly logo

C# Cookbook by Jay Hilyard, Stephen Teilhet

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

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

Problem

You need to determine whether a string is at the head or tail of a second string. In addition, the case sensitivity of the search needs to be controlled.

Solution

Use the EndsWith or StartsWith instance methods on a string object. Comparisons with EndsWith and StartsWith are always case-sensitive. The following code compares the value in the string variable head to the beginning of the string Test:

string head = "str";
string test = "strVarName";
bool isFound = test.StartsWith(head);

The following example compares the value in the string variable Tail to the end of the string test:

string tail = "Name";
string test = "strVarName";
bool isFound = test.EndsWith(tail);

In both examples, the isFound Boolean variable is set to true, since each string is found in test.

To do a case-insensitive comparison, employ the static string.Compare method. The following two examples modify the previous two examples by performing a case-insensitive comparison. The first is equivalent to a case-insensitive StartsWith string search:

string head = "str";
string test = "strVarName";
int isFound = string.Compare(head, 0, test, 0, head.Length, true);

The second is equivalent to a case-insensitive EndsWith string search:

string tail = "Name";
string test = "strVarName";
int isFound = string.Compare(tail, 0, test, (test.Length - tail.Length), 
                             tail.Length, true);

Discussion

Use the BeginsWith or EndsWith instance methods to do a case-sensitive ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required