index of string c# code example

Example 1: get string character by index c#

//Returns a char
myString.[0];

//Returns a string
myString.[0].ToString();

Example 2: c# find index of character in string

string str = "Now is the time.";
int index = str.IndexOf("h");

Example 3: c sharp index of substring

// To find the index of the first substring in a string use
// 'IndexOf()'
string str = "Hello World!"
str.IndexOf("o"); // Output: 4

// You can give a starting index and a length to search at
str.IndexOf("o", 6, 4); // Output: 7

// To find the last instance of a substring use 'LastIndexOf()'
str.LastIndexOf("o"); // Output: 7

Example 4: index of string c#

string br1 = "0----+----1----+----2----+----3----+----4----+----5----+----6----+---";
string br2 = "012345678901234567890123456789012345678901234567890123456789012345678";
string str = "Now is the time for all good men to come to the aid of their country.";
int start;
int at;
int end;
int count;

end = str.Length;
start = end/2;
Console.WriteLine();
Console.WriteLine("All occurrences of 'he' from position {0} to {1}.", start, end-1);
Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str);
Console.Write("The string 'he' occurs at position(s): ");

count = 0;
at = 0;
while((start <= end) && (at > -1))
{
    // start+count must be a position within -str-.
    count = end - start;
    at = str.IndexOf("he", start, count);
    if (at == -1) break;
    Console.Write("{0} ", at);
    start = at+1;
}
Console.WriteLine();

/*
This example produces the following results:

All occurrences of 'he' from position 34 to 68.
0----+----1----+----2----+----3----+----4----+----5----+----6----+---
012345678901234567890123456789012345678901234567890123456789012345678
Now is the time for all good men to come to the aid of their country.

The string 'he' occurs at position(s): 45 56

*/

Example 5: letter at index of string c#

string s = "hello";
char c = s[1];
// now c == 'e'

Example 6: strinng.indexOf c#

int index = String.IndexOf(char x);
int index = String.IndexOf(string x);