string.indexof c# return value code example
Example 1: 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 2: strinng.indexOf c#
int index = String.IndexOf(char x);
int index = String.IndexOf(string x);