1. Additional string operators
length
size
find
substr

2. The “length” function
If we apply length function to a string, it will return the number
of characters in that string.
Examples:
string firstName;
string lastname;
firstName = “Cynthia”;
cout << firstName . length() << endl; // prints 7
lastName = “Lokker”;
Cout << lastName . Length() << endl; // prints 6

3. Error message If you forget to use dot notation and write simply:
length()
You will get a syntax error message:
“undeclared identifier.”
Compiler will think you are trying to call an ordinary function,
named length without declaration.
Compiler will not recognize that you are trying to call the length
function associated with the string type.

4. The find function
We use “find” function to find the first occurrence of a particular
Substring.
The function “find” returns an integer to indicate the position of
the substring in the searching string.
Examples:
string str;
str = “Introduction to programming”;
Function calls Value returned by function
str . find(“tion”)
str . find(“Intro”)
str . find(“prog”)
Str . Find(“or”) string::npos, a largest
possible value

5. The substr function
We use the “substr” function to get a particular substring of a string.
The “substr” function has two parameters:
first parameter gives the position of the first character of the
substring in the string
second parameter gives the length of the substring.
Examples:
string str;
str = “Introduction to programming”;
Function call Value returned by the function
str . substr(0, 12) Introduction
str . substr(8, 7) tion to
str . substr(40, 10) None. Program terminates
with an execution error