Description |
Returns the index of the Needle string in the current (haystack) string.
If not found, then -1 is returned.
The scan is case sensitive.
The scan starts at the beginning and continues until either the Needle is found, or the string is exhausted.
The scan can be forced to commence from the Start character, and can be limited to Count scan characters.
|
| Notes | Very Important : Methods in .Net treat strings as starting at 0, unlike traditional Delphi where they started at 1.
|
|
Microsoft MSDN Links |
system
system.String
|
|
|
A simple example |
program Project1;
{$APPTYPE CONSOLE}
var
strA : String;
result : Integer;
begin
strA := '123456789';
Console.WriteLine('strA = ' + strA);
result := strA.IndexOf('45');
Console.WriteLine('Index of 45 = ' + result.ToString);
result := strA.IndexOf('54');
Console.WriteLine('Index of 54 = ' + result.ToString);
Console.ReadLine;
end.
| Show full unit code | strA = 123456789
Index of 45 = 3
Index of 54 = -1
| | Specifying a start position | program Project1;
{$APPTYPE CONSOLE}
var
strA : String;
result : Integer;
begin
strA := 'ABCABCABC';
result := strA.IndexOf('AB', 5);
Console.WriteLine('strA = ' + strA);
Console.WriteLine('Looking for AB, starting from index 5');
Console.WriteLine('Result = ' + result.ToString);
Console.ReadLine;
end.
| Show full unit code | strA = ABCABCABC
Looking for AB, starting from index 5
Result = 6
| | Specifying a start position and limit in the character scan | program Project1;
{$APPTYPE CONSOLE}
var
strA : String;
result : Integer;
begin
strA := 'ABCABCABC';
Console.WriteLine('Guide= 0123456789');
Console.WriteLine('strA = ' + strA);
result := strA.IndexOf('ABC', 5, 3);
Console.WriteLine('Looking for ABC, starting @ 5 for count of 3');
Console.WriteLine('Result = ' + result.ToString);
result := strA.IndexOf('ABC', 5, 4);
Console.WriteLine('Looking for ABC, starting @ 5 for count of 4');
Console.WriteLine('Result = ' + result.ToString);
Console.ReadLine;
end.
| Show full unit code | Guide= 0123456789
strA = ABCABCABC
Looking for ABC, starting @ 5 for count of 3
Result = -1
Looking for ABC, starting @ 5 for count of 4
Result = 6
|
|
|
|