C++ string manipulation

Find a string within a string
Searching a string within another string is a breeze with std::string. The Standard Library defines several specialized overloaded versions of string::find() that take const string&, const char *, or just char as a sought-after value (the substring). Here, I will only show how to use the first version for locating a string object within another string objects; implementing other versions should be a cinch.

string verse="Franco's rain in Spain";
string sought = "rain";
int pos=verse.find(sought); // pos=9

Substring Replacement
Suppose you want to replace the sought-after value with another substring, just as your word processor does when you use "search and replace." The replace() function (which also has several overloaded versions) does the trick. The canonical version takes three arguments: the position, or offset into which the replacement string should be written; the length of the substring to be replaced; and an overriding string. For example, the following code corrects the typo in phrase by replacing "rain" with "reign":

phrase.replace(pos, sought.size(), replacement);
cout<