String::IndexOf Method (String, Int32)
Reports the zero-based index of the first occurrence of the specified string in this instance. The search starts at a specified character position.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- value
- Type: System::String
The string to seek.
- startIndex
- Type: System::Int32
The search starting position.
Return Value
Type: System::Int32The zero-based index position of value if that string is found, or -1 if it is not. If value is String::Empty, the return value is startIndex.
| Exception | Condition |
|---|---|
| ArgumentNullException | value is nullptr. |
| ArgumentOutOfRangeException | startIndex is negative. -or- startIndex is less than zero or greater than the length of this string. |
Index numbering starts from zero. The startIndex parameter can range from 0 to the length of the string instance. If startIndex equals the length of the string instance, the method returns -1.
This method performs a word (case-sensitive and culture-sensitive) search using the current culture. The search begins at the startIndex character position of this instance and continues until the last character position.
Notes to CallersAs explained in Best Practices for Using Strings in the .NET Framework, we recommend that you avoid calling string comparison methods that substitute default values and instead call methods that require parameters to be explicitly specified. To find the first index of a substring that occurs after a particular character position by using the comparison rules of the current culture, call the IndexOf(String, Int32, StringComparison) method overload with a value of StringComparison::CurrentCulture for its comparisonType parameter.
The following example searches for all occurrences of a specified string within a target string.
using namespace System; int main() { String^ strSource = "This is the string which we will perform the search on"; Console::WriteLine( "The search string is: {0}\"{1}\" {0}", Environment::NewLine, strSource ); String^ strTarget = ""; int found = 0; int totFinds = 0; do { Console::Write( "Please enter a search value to look for in the above string (hit Enter to exit) ==> " ); strTarget = Console::ReadLine(); if ( !strTarget->Equals( "" ) ) { for ( int i = 0; i < strSource->Length; i++ ) { found = strSource->IndexOf( strTarget, i ); if ( found > 0 ) { totFinds++; i = found; } else break; } } else return 0; Console::WriteLine( "{0}The search parameter '{1}' was found {2} times. {0}", Environment::NewLine, strTarget, totFinds ); totFinds = 0; } while ( true ); }
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.