IndexOf usage of C #

IndexOf ()
　　Finds the position of the first occurrence of a specified character or string in a string, and returns the value of the first index;

return value

　　The index position of value if the character is found, or 1 if not found;

But sometimes we need to find the first text of a character or string from the right side of the string, and then you can't use indexof (), but use LastIndexOf ();

LastIndexOf ()

　　Reports the index position of the last occurrence of the specified string within this instance.

Example:

string " ABCDEFGABC "  = str. IndexOf ("a"// returns 0label2.text = str. LastIndexOf ("a"). ToString (); // returns 7

IndexOf usage of C #